fisher control valve handbook
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CONTROL VALVEHANDBOOK
Fourth Edition
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NORTH AMERICAEmerson Process ManagementMarshalltown, Iowa 50158 USAT 1 (641) 754−3011F 1 (641) 754−2830www.EmersonProcess.com/Fisher
LATIN AMERICAEmerson Process ManagementSorocaba, Sao Paulo 18087 BrazilT +(55)(15)238−3788F +(55)(15)228−3300www.EmersonProcess.com/Fisher
EUROPEEmerson Process ManagementCernay 68700 FranceT +(33) (0)3 89 37 64 00F +(33) (0)3 89 37 65 18www.EmersonProcess.com/Fisher
MIDDLE EAST & AFRICAEmerson FZEDubai, United Arab EmiratesT +971 4 883 5235F +971 4 883 5312www.EmersonProcess.com/Fisher
ASIA PACIFICEmerson Process Management Singapore 128461 SingaporeT +(65) 6777 8211F +(65) 6777 0947www.EmersonProcess.com/Fisher
Fisher is a mark owned by Fisher Controls International LLC, a member of the EmersonProcess Management business division of Emerson Electric Co. The Emerson logo is atrademark and service mark of Emerson Electric Co. All other marks are the property of theirrespective owners.
The contents of this publication are presented for informational purposes only, and whileevery effort has been made to ensure their accuracy, they are not to be construed aswarranties or guarantees, express or implied, regarding the products or services describedherein or their use or applicability. We reserve the right to modify or improve the designs orspecifications of such products at any time without notice.
Neither Emerson, Emerson Process Management nor any of their affiliated entities assumesresponsibility for the selection, use and maintenance of any product. Responsibility for theselection, use and maintenance of any product remains with the purchaser and end-user.
Printed in U.S.A.
�Fisher Controls International LLC 2005
D101881X012
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Preface to Fourth Edition
Control valves are an increasingly vital component of modern manufacturing aroundthe world. Properly selected and maintained control valves increase efficiency, safe-ty, profitability, and ecology.
The Control Valve Handbook has been a primary reference since its first printing in1965. This fourth edition presents vital information on control valve performance andthe latest technologies.
� Chapter 1 offers an introduction to control valves including definitions forcommon control valve and instrumentation terminology.
� Chapter 2 develops the vital topic of control valve performance.
� Chapter 3 covers valve and actuator types.
� Chapter 4 describes digital valve controllers, analog positioners, boosters,and other control valve accessories.
� Chapter 5 is a comprehensive guide to selecting the best control valve foran application.
� Chapter 6 covers the selection and use of special control valves.
� Chapter 7 covers desuperheaters, steam conditioning valves, and turbinebypass systems.
� Chapter 8 offers typical control valve installation and maintenance proce-dures.
� Chapter 9 includes information on control valve standards and approvalagencies throughout the world.
� Chapter 10 offers useful tables of engineering reference data.
� Chapter 11 includes piping reference data.
� Chapter 12 is a handy resource for common conversions.
The Control Valve Handbook is both a textbook and a reference on the strongest linkin the control loop: the control valve and its accessories. This book includes exten-sive and proven knowledge from leading experts in the process control field includ-ing contributions from the ISA and the Crane Company.
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Table of Contents
Chapter 1. Introduction to Control Valves 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . What Is A Control Valve? 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Process Control Terminology 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sliding-Stem Control Valve Terminology 6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary-Shaft Control Valve Terminology 13. . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Functions and Characteristics Terminology 16. . . . . . . . . . . . . Other Process Control Terminology 18. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 2. Control Valve Performance 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Process Variability 23. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Dead Band 25. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Actuator-Positioner Design 27. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Response Time 29. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Type And Characterization 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Sizing 36. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Economic Results 37. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 39. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 3. Valve and Actuator Types 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valves 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Globe Valves 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Single-Port Valve Bodies 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Balanced-Plug Cage-Style Valve Bodies 43. . . . . . . . . . . . . . . . . . . . . . High Capacity, Cage-Guided Valve Bodies 43. . . . . . . . . . . . . . . . . . . . Port-Guided Single-Port Valve Bodies 44. . . . . . . . . . . . . . . . . . . . . . . . . Double-Ported Valve Bodies 44. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Three-Way Valve Bodies 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Rotary Valves 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Butterfly Valve Bodies 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . V-Notch Ball Control Valve Bodies 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . Eccentric-Disk Control Valve Bodies 46. . . . . . . . . . . . . . . . . . . . . . . . . . Eccentric-Plug Control Valve Bodies 47. . . . . . . . . . . . . . . . . . . . . . . . . .
Control Valve End Connections 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Screwed Pipe Threads 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bolted Gasketed Flanges 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Welding End Connections 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Body Bonnets 49. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Extension Bonnets 50. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bellows Seal Bonnets 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control Valve Packing 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PTFE V-Ring 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Laminated and Filament Graphite 52. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . USA Regulatory Requirements for Fugitive Emissions 53. . . . . . . . . . . . .
Single PTFE V-Ring Packing 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL� PTFE Packing 54. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL� Duplex Packing 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . KALREZ� Packing 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO−SEAL� Graphite ULF 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIGH-SEAL� Graphite ULF 55. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ENVIRO-SEAL� Graphite for Rotary Valves 57. . . . . . . . . . . . . . . . . . . . . Graphite Ribbon for Rotary Valves 57. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Characterization of Cage-Guided Valve Bodies 58. . . . . . . . . . . . . . . . . . . . . . Characterized Valve Plugs 59. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Plug Guiding 60. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Restricted-Capacity Control Valve Trim 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Actuators 61. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diaphragm Actuators 62. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Piston Actuators 63. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electrohydraulic Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manual Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rack and Pinion Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electric Actuators 64. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 4. Control Valve Accessories 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Positioners 67. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Control Valve Accessories 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Limit Switches 69. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Solenoid Valve Manifold 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Pressure Regulator 71. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pneumatic Lock-Up Systems 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fail-Safe Systems for Piston Actuators 72. . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Pneumatic Transducers 72. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Pneumatic Valve Positioners 72. . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Diagnostics 74. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 5. Control Valve Selection 75. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Body Materials 76. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Designations for the High Nickel Alloys 77. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure-Temperature Ratings for Standard Class 78. . . . . . . . . . . . . . . . . . .
Cast Carbon Steel (ASTM A216 Grade WCC) 78. . . . . . . . . . . . . . . . . . . . Cast Chromium-Molybdenum Steel (ASTM A217 Grade WC9) 79. . . . . . Cast Chromium-Molybdenum Steel (ASTM A217 Grade C5) 80. . . . . . . . Cast Type 304 Stainless Steel (ASTM A351 Grade CF3) 81. . . . . . . . . . . Cast Type 316 Stainless Steel (ASTM A351 Grades CF8M and CG8M) 82
Pressure-Temperature Ratings for ASTM A216 Cast Iron Valves 84. . . . . . . Pressure-Temperature Ratings for ASTM B61 and B62 Cast Bronze Valves 85. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Flanged Globe-Style Control Valves 86. . . . . Face-to-Face Dimensions for Buttweld-End Globe-Style Control Valves 88. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Socket Weld-End Globe-Style Control Valves 89. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Screwed-End Globe-Style Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Centerline Dimensions for Raised Face Globe-Style Angle Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Separable Flanged Globe-Style Control Valves 90. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for Flangeless, Partial-Ball Control Valves 91. . . Face-to-Face Dimensions for Single Flange (Lug-Type) and Flangeless (Wafer-Type) Butterfly Control Valves 91. . . . . . . . . . . . . . . . . . . . Face-to-Face Dimensions for High Pressure Butterfly Valves with Offset Design 92. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wear & Galling Resistance Chart Of Material Combinations 92. . . . . . . . . . . Control Valve Seat Leakage Classifications 93. . . . . . . . . . . . . . . . . . . . . . . . . Class VI Maximum Seat Leakage Allowable 94. . . . . . . . . . . . . . . . . . . . . . . . Typical Valve Trim Material Temperature Limits 94. . . . . . . . . . . . . . . . . . . . . . Service Temperature Limitations for Elastomers 95. . . . . . . . . . . . . . . . . . . . . Ambient Temperature Corrosion Information 96. . . . . . . . . . . . . . . . . . . . . . . Elastomer Information 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fluid Compatibility 104. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Flow Characteristics 108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flow Characteristics 108. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selection of Flow Characteristic 109. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Valve Sizing 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sizing Valves for Liquids 110. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Abbreviations and Terminology 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Equation Constants 113. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Determining Fp, the Piping Geometry Factor 114. . . . . . . . . . . . . . . . . . . . .
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Determining qmax (the Maximum Flow Rate) or �Pmax (the Allowable Sizing Pressure Drop) 115. . . . . . . . . . . . . . . . . . . . . . . . . . . Determining qmax (the Maximum Flow Rate) 115. . . . . . . . . . . . . . . . . . . . . Determining �Pmax (the Allowable Sizing Pressure Drop) 115. . . . . . . . . . Liquid Sizing Sample Problem 117. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sizing Valves for Compressible Fluids 119. . . . . . . . . . . . . . . . . . . . . . . . . . . Determining xTP, the Pressure Drop Ratio Factor 121. . . . . . . . . . . . . . . . . Compressible Fluid Sizing Sample Problem No. 1 121. . . . . . . . . . . . . . . . Compressible Fluid Sizing Sample Problem No. 2 123. . . . . . . . . . . . . . . . Representative Sizing Coefficients for Single-Ported Globe-Style Valve Bodies 126. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Representative Sizing Coefficients for Rotary-Shaft Valves 127. . . . . . .
Actuator Sizing 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Globe Valves 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A. Unbalance Force 129. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Typical Unbalance Areas of Control Valves 129. . . . . . . . . . . . . . . .
B. Force to Provide Seat Load 130. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. Packing Friction 131. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Packing Friction Values 132. . . . . . . . . . . . . . . . . . . . . . . . . . D. Additional Forces 132. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator Force Calculations 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rotary Actuator Sizing 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Torque Equations 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Breakout Torque 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dynamic Torque 133. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Rotary Shaft Valve Torque Factors 134. . . . . . . . . . . . . . . . . . . . . . . . . V-Notch Ball Valve with Composition Seal 134. . . . . . . . . . . . . . . . . . . . . . . . . High Performance Butterfly Valve with Composition Seal 134. . . . . . . . . . . . .
Maximum Rotation 134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-Destructive Test Procedures 134. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Magnetic Particle (Surface) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . Liquid Penetrant (Surface) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . . Radiographic (Volumetric) Examination 135. . . . . . . . . . . . . . . . . . . . . . . . . Ultrasonic (Volumetric) Examination 136. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cavitation and Flashing 136. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Choked Flow Causes Flashing and Cavitation 136. . . . . . . . . . . . . . . . . . . Valve Selection for Flashing Service 137. . . . . . . . . . . . . . . . . . . . . . . . . . . Valve Selection for Cavitation Service 138. . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Prediction 139. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Aerodynamic 139. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hydrodynamic 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Noise Control 140. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Noise Summary 143. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Packing Selection 144. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Packing Selection Guidelines for Sliding−Stem Valves 145. . . . . . . . . . . . . . . Packing Selection Guidelines for Rotary Valves 146. . . . . . . . . . . . . . . . . . . .
Chapter 6. Special Control Valves 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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High Capacity Control Valves 147. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Low Flow Control Valves 148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . High-Temperature Control Valves 148. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cryogenic Service Valves 149. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Customized Characteristics and Noise Abatement Trims 150. . . . . . . . . . . . . Control Valves for Nuclear Service in the USA 151. . . . . . . . . . . . . . . . . . . . . . Valves Subject to Sulfide Stress Cracking 151. . . . . . . . . . . . . . . . . . . . . . . . .
Pre-2003 Revisions of MR0175 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NACE MR0175/ISO 15156 152. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NACE MR0103 153. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 7. Steam Conditioning Valves 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Understanding Desuperheating 155. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Technical Aspects of Desuperheating 156. . . . . . . . . . . . . . . . . . . . . . . . . . Typical Desuperheater Designs 158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fixed Geometry Nozzle Design 158. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Variable Geometry Nozzle Design 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self-Contained Design 159. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steam Atomized Design 160. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Geometry-Assisted Wafer Design 161. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Understanding Steam Conditioning Valves 161. . . . . . . . . . . . . . . . . . . . . . . . Steam Conditioning Valves 162. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Steam Cooler 164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Steam Sparger 164. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Understanding Turbine Bypass Systems 165. . . . . . . . . . . . . . . . . . . . . . . . . . Turbine Bypass System Components 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Turbine Bypass Valves 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Turbine Bypass Water Control Valves 166. . . . . . . . . . . . . . . . . . . . . . . . . . Electro-Hydraulic System 166. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 8. Installation and Maintenance 167. . . . . . . . . . . . . . . . . . . . . . . . . . . Proper Storage and Protection 167. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Proper Installation Techniques 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Read the Instruction Manual 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Be Sure the Pipeline Is Clean 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Inspect the Control Valve 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Use Good Piping Practices 168. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Control Valve Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reactive Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Preventive Maintenance 169. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Predictive Maintenance 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Using Control Valve Diagnostics 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instrument Air Leakage 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Supply Pressure 170. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Travel Deviation and Relay Adjustment 171. . . . . . . . . . . . . . . . . . . . . . . .
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Instrument Air Quality 171. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . In-Service Friction and Friction Trending 171. . . . . . . . . . . . . . . . . . . . . . . Other Examples 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continued Diagnostics Development 172. . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator Diaphragm 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Stem Packing 172. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seat Rings 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Grinding Metal Seats 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Replacing Seat Rings 173. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bench Set 174. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 9. Standards and Approvals 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Control Valve Standards 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
American Petroleum Institute (API) 175. . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Society of Mechanical Engineers (ASME) 175. . . . . . . . . . . . . . European Committee for Standardization (CEN) 176. . . . . . . . . . . . . . . . .
European Industrial Valve Standards 176. . . . . . . . . . . . . . . . . . . . . . . . European Material Standards 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . European Flange Standards 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Controls Institute (FCI) 176. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Society of America (ISA) 177. . . . . . . . . . . . . . . . . . . . . . . . . . . . International Electrotechnical Commission (IEC) 177. . . . . . . . . . . . . . . . . International Standards Organization (ISO) 178. . . . . . . . . . . . . . . . . . . . . . Manufacturers Standardization Society (MSS) 178. . . . . . . . . . . . . . . . . . . NACE International 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Approvals for Hazardous (Classified) Locations 178. . . . . . . . . . . . . References 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Canadian Standards Association (CSA) Standards 178. . . . . . . . . . . . European Committee for Electrotechnical Standardization (CENELEC) Standards 178. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Instrument Society of America (ISA) Standards 178. . . . . . . . . . . . . . . . International Electrotechnical Commission (IEC) Standards 178. . . . . National Electrical Manufacturer’s Association (NEMA) Standards 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . National Fire Protection Association (NFPA) Standards 179. . . . . . . . .
North American Approvals 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Approval Agencies 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Types of Protection 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nomenclature 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazardous Location Classification 179. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Code 180. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NEMA Enclosure Rating 181. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Locations 181. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazardous (Classified) Locations 182. . . . . . . . . . . . . . . . . . . . . . . . . . .
CSA Enclosure Ratings 182. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intrinsically Safe Apparatus 182. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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Entity Concept 182. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CSA System Parameter Concept 183. . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop Schematic (Control Drawing) 183. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Comparison of Protection Techniques 183. . . . . . . . . . . . . . . . . . . . . . . . . .
Explosion-proof Technique 183. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 184. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 184. . . . . . . . . . . . . . . . . . . . . . . . . Installation Requirements 184. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Intrinsically Safe Technique 184. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 184. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 184. . . . . . . . . . . . . . . . . . . . . . . . .
Dust Ignition−proof Technique 184. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-Incendive Technique 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Advantages of this Technique 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 185. . . . . . . . . . . . . . . . . . . . . . . . .
European and Asia/Pacific Approvals 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Approval Agencies 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CENELEC Approvals 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Types of Protection 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flameproof 185. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Increased Safety 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Intrinsically Safe 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Non-Incendive 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hazardous Location Classification 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Group 186. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Zone 187. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Temperature Code 187. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . IEC Enclosure Rating 187. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NEMA and IEC Enclosure Rating Comparison 188. . . . . . . . . . . . . . . . . . . Comparison of Protection Techniques 188. . . . . . . . . . . . . . . . . . . . . . . . . .
Flameproof Technique 188. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 188. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 188. . . . . . . . . . . . . . . . . . . . . . . . .
Increased Safety Technique 188. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . .
Intrinsically Safe Technique 189. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . .
Type n Technique 189. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Advantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . . . . . Disadvantages of this Technique 189. . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 10. Engineering Data 191. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard Specifications For Valve Materials 191. . . . . . . . . . . . . . . . . . . . . . .
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Valve Materials Properties for Pressure−Containing Components 197. . . . . Physical Constants of Hydrocarbons 200. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specific Heat Ratio (K) 202. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Physical Constants of Various Fluids 203. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Refrigerant 717 (Ammonia) 206. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Properties of Water 211. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Properties of Saturated Steam 212. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Properties of Superheated Steam 219. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Velocity of Liquids in Pipe 226. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flow of Water Through Schedule 40 Steel Pipe 228. . . . . . . . . . . . . . . . . . . Flow of Air Through Schedule 40 Steel Pipe 232. . . . . . . . . . . . . . . . . . . . . . Calculations for Pipe Other than Schedule 40 236. . . . . . . . . . . . . . . . . . . . . .
Chapter 11. Pipe Data 237. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pipe Engagement 237. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Carbon and Alloy Steel − Stainless Steel 238. . . . . . . . . . . . . . . . . . . . . . . . . . American Pipe Flange Dimensions − Diameter of Bolt Circle�Inches 251. . American Pipe Flange Dimensions − Number of Stud Bolts and Diameter in Inches 252. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . American Pipe Flange Dimensions − Flange Diameter−Inches 253. . . . . . . . American Pipe Flange Dimensions − Flange Thickness for Flange Fittings 254. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 16 255. . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 25 256. . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 40 257. . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 63 258. . . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 100 259. . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 160 259. . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 250 260. . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 320 260. . . . . . . . . . . . . . . . . . . . . . . . . . . Cast Steel Flange Standard for PN 400 261. . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter 12. Conversions and Equivalents 263. . . . . . . . . . . . . . . . . . . . . . . . . Length Equivalents 263. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Whole Inch−Millimeter Equivalents 263. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fractional Inches To Millimeters 264. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Additional Fractional/Decimal Inch−Millimeter Equivalents 264. . . . . . . . . . . . Area Equivalents 266. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Volume Equivalents 266. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Volume Rate Equivalents 266. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mass Conversion—Pounds to Kilograms 267. . . . . . . . . . . . . . . . . . . . . . . . . . Pressure Equivalents 268. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure Conversion—Pounds per Square Inch to Bar 268. . . . . . . . . . . . . . Temperature Conversion Formulas 269. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Temperature Conversions 269. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.P.I. and Baumé Gravity Tables and Weight Factors 271. . . . . . . . . . . . . . .
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Equivalent Volume and Weight Flow Rates of Compressible Fluids 273. . . . Viscosity Conversion Nomograph 274. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Other Useful Conversions 275. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Metric Prefixes and Symbols 275. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subject Index 277. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
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1
Chapter 1
Introduction to Control Valves
What Is A Control Valve?Process plants consist of hundreds, oreven thousands, of control loops allnetworked together to produce a prod-uct to be offered for sale. Each ofthese control loops is designed tokeep some important process variablesuch as pressure, flow, level, temper-ature, etc. within a required operatingrange to ensure the quality of the endproduct. Each of these loops receivesand internally creates disturbancesthat detrimentally affect the processvariable, and interaction from otherloops in the network provides distur-bances that influence the processvariable.
To reduce the effect of these load dis-turbances, sensors and transmitterscollect information about the processvariable and its relationship to somedesired set point. A controller thenprocesses this information and de-
cides what must be done to get theprocess variable back to where itshould be after a load disturbance oc-curs. When all the measuring,comparing, and calculating are done,some type of final control elementmust implement the strategy selectedby the controller.
The most common final control ele-ment in the process control industriesis the control valve. The control valvemanipulates a flowing fluid, such asgas, steam, water, or chemical com-pounds, to compensate for the loaddisturbance and keep the regulatedprocess variable as close as possibleto the desired set point.
Many people who talk about controlvalves or valves are really referring toa control valve assembly. The controlvalve assembly typically consists ofthe valve body, the internal trim parts,an actuator to provide the motive pow-er to operate the valve, and a variety
Chapter 1. Introduction to Control Valves
2
of additional valve accessories, whichcan include positioners, transducers,supply pressure regulators, manualoperators, snubbers, or limit switches.Other chapters of this handbook sup-ply more detail about each of thesecontrol valve assembly components.
Whether it is called a valve, controlvalve or a control valve assembly isnot as important as recognizing thatthe control valve is a critical part of thecontrol loop. It is not accurate to saythat the control valve is the most im-portant part of the loop. It is useful tothink of a control loop as an instru-mentation chain. Like any other chain,the whole chain is only as good as itsweakest link. It is important to ensurethat the control valve is not the weak-est link.
Following are definitions for processcontrol, sliding-stem control valve,rotary-shaft control valve, and othercontrol valve functions and character-istics terminology.
NOTE:
Definitions with an as-terisk (*) are from theISA Control Valve Ter-minology standardS75.05, used with per-mission.
Process ControlTerminologyAccessory: A device that ismounted on the actuator to comple-ment the actuator’s function and makeit a complete operating unit. Examplesinclude positioners, supply pressureregulators, solenoids, and limitswitches.
Actuator*: A pneumatic, hydraulic,or electrically powered device thatsupplies force and motion to open orclose a valve.
Actuator Assembly: An actuator,including all the pertinent accessoriesthat make it a complete operating unit.
Backlash: The general name givento a form of dead band that resultsfrom a temporary discontinuity be-tween the input and output of a devicewhen the input of the device changesdirection. Slack, or looseness of a me-chanical connection is a typical exam-ple.
Capacity* (Valve): The rate of flowthrough a valve under stated condi-tions.
Closed Loop: The interconnectionof process control components suchthat information regarding the processvariable is continuously fed back tothe controller set point to provide con-tinuous, automatic corrections to theprocess variable.
Controller: A device that operatesautomatically by use of some estab-lished algorithm to regulate a con-trolled variable. The controller inputreceives information about the statusof the process variable and then pro-vides an appropriate output signal tothe final control element.
Control Loop: (See Closed Loop.)
Control Range: The range of valvetravel over which a control valve canmaintain the installed valve gain be-tween the normalized values of 0.5and 2.0.
Control Valve: (See Control ValveAssembly.)
Control Valve Assembly: Includesall components normally mounted onthe valve: the valve body assembly,actuator, positioner, air sets, transduc-ers, limit switches, etc.
Dead Band: The range throughwhich an input signal can be varied,upon reversal of direction, without ini-tiating an observable change in theoutput signal. Dead band is the namegiven to a general phenomenon thatcan apply to any device. For the valve
Chapter 1. Introduction to Control Valves
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Figure 1-1. Process Dead Band
A7152 / IL
assembly, the controller output (CO) isthe input to the valve assembly andthe process variable (PV) is the outputas shown in figure 1-1. When the termDead Band is used, it is essential thatboth the input and output variablesare identified, and that any tests tomeasure dead band be under fullyloaded conditions. Dead band is typi-cally expressed as a percent of theinput span.
Dead Time: The time interval (Td) inwhich no response of the system isdetected following a small (usually0.25% - 5%) step input. It is measuredfrom the time the step input is initiatedto the first detectable response of thesystem being tested. Dead Time canapply to a valve assembly or to theentire process. (See T63.)
Disk: A valve trim element used tomodulate the flow rate with either lin-ear or rotary motion. Can also be re-ferred to as a valve plug or closuremember.
Equal Percentage Characteristic*:An inherent flow characteristic that, forequal increments of rated travel, willideally give equal percentage changesof the flow coefficient (Cv) (figure 1-2).
Final Control Element: The devicethat implements the control strategydetermined by the output of the con-troller. While the final control elementcan be a damper, a variable speeddrive pump, or an on-off switching de-
vice, the most common final controlelement in the process control indus-tries is the control valve assembly.The control valve manipulates a flow-ing fluid, such as gasses, steam, wa-ter, or chemical compounds, to com-pensate for the load disturbance andkeep the regulated process variableas close as possible to the desired setpoint.
First-Order: A term that refers to thedynamic relationship between the in-put and output of a device. A first-or-der system or device is one that hasonly one energy storage device andwhose dynamic transient relationshipbetween the input and output is char-acterized by an exponential behavior.
Friction: A force that tends to op-pose the relative motion between twosurfaces that are in contact with eachother. The friction force is a function ofthe normal force holding these twosurfaces together and the characteris-tic nature of the two surfaces. Frictionhas two components: static frictionand dynamic friction. Static friction isthe force that must be overcome be-fore there is any relative motion be-tween the two surfaces. Once relativemovement has begun, dynamic fric-tion is the force that must be over-come to maintain the relative motion.Running or sliding friction are colloqui-al terms that are sometimes used todescribe dynamic friction. Stick/slip or“stiction” are colloquial terms that aresometimes used to describe static fric-tion. Static friction is one of the majorcauses of dead band in a valve as-sembly.
Gain: An all-purpose term that canbe used in many situations. In its mostgeneral sense, gain is the ratio of themagnitude of the output change of agiven system or device to the magni-tude of the input change that causedthe output change. Gain has two com-ponents: static gain and dynamicgain. Static gain is the gain relation-ship between the input and output andis an indicator of the ease with whichthe input can initiate a change in the
Chapter 1. Introduction to Control Valves
4
Figure 1-2. Inherent ValveCharacteristics
A3449/IL
output when the system or device is ina steady-state condition. Sensitivity issometimes used to mean static gain.Dynamic gain is the gain relationshipbetween the input and output whenthe system is in a state of movementor flux. Dynamic gain is a function offrequency or rate of change of the in-put.
Hysteresis*: The maximum differ-ence in output value for any single in-put value during a calibration cycle,excluding errors due to dead band.
Inherent Characteristic*: The rela-tionship between the flow coefficientand the closure member (disk) travelas it is moved from the closed positionto rated travel with constant pressuredrop across the valve.
Typically these characteristics areplotted on a curve where the horizon-tal axis is labeled in percent travel andthe vertical axis is labeled as percentflow (or Cv) (figure 1-2). Becausevalve flow is a function of both thevalve travel and the pressure dropacross the valve, conducting flowcharacteristic tests at a constant pres-sure drop provides a systematic wayof comparing one valve characteristicdesign to another. Typical valve char-acteristics conducted in this manner
are named Linear, Equal-Percentage,and Quick Opening (figure 1-2).
Inherent Valve Gain: The magni-tude ratio of the change in flowthrough the valve to the change invalve travel under conditions ofconstant pressure drop. Inherentvalve gain is an inherent function ofthe valve design. It is equal to theslope of the inherent characteristiccurve at any travel point and is a func-tion of valve travel.
Installed Characteristic*: The rela-tionship between the flow rate and theclosure member (disk) travel as it ismoved from the closed position torated travel as the pressure dropacross the valve is influenced by thevarying process conditions. (SeeValve Type and Characterization inChapter 2 for more details on how theinstalled characteristic is determined.)
Installed Valve Gain: The magni-tude ratio of the change in flowthrough the valve to the change invalve travel under actual process con-ditions. Installed valve gain is thevalve gain relationship that occurswhen the valve is installed in a specif-ic system and the pressure drop is al-lowed to change naturally accordingto the dictates of the overall system.The installed valve gain is equal to theslope of the installed characteristiccurve, and is a function of valve travel.(See Valve Type and Characterizationin Chapter 2 for more details on howthe installed gain is determined.)
I/P: Shorthand for current-to-pres-sure (I-to-P). Typically applied to inputtransducer modules.
Linearity*: The closeness to which acurve relating to two variables approx-imates a straight line. (Linearity alsomeans that the same straight line willapply for both upscale and downscaledirections. Thus, dead band as de-fined above, would typically be con-sidered a non-linearity.)
Linear Characteristic*: An inherentflow characteristic that can be repre-
Chapter 1. Introduction to Control Valves
5
sented by a straight line on a rectan-gular plot of flow coefficient (Cv) ver-sus rated travel. Therefore equalincrements of travel provide equal in-crements of flow coefficient, Cv (figure1-2).
Loop: (See Closed Loop.)
Loop Gain: The combined gain of allthe components in the loop whenviewed in series around the loop.Sometimes referred to as open-loopgain. It must be clearly specifiedwhether referring to the static loopgain or the dynamic loop gain at somefrequency.
Manual Control: (See Open Loop.)
Open Loop: The condition wherethe interconnection of process controlcomponents is interrupted such thatinformation from the process variableis no longer fed back to the controllerset point so that corrections to theprocess variable are no longer pro-vided. This is typically accomplishedby placing the controller in the manualoperating position.
Packing: A part of the valve assem-bly used to seal against leakagearound the valve disk or stem.
Positioner*: A position controller(servomechanism) that is mechanical-ly connected to a moving part of a fi-nal control element or its actuator andthat automatically adjusts its output tothe actuator to maintain a desiredposition in proportion to the input sig-nal.
Process: All the combined elementsin the control loop, except the control-ler. The process typically includes thecontrol valve assembly, the pressurevessel or heat exchanger that is beingcontrolled, as well as sensors, pumps,and transmitters.
Process Gain: The ratio of thechange in the controlled process vari-able to a corresponding change in theoutput of the controller.
Process Variability: A precise statis-tical measure of how tightly the pro-cess is being controlled about the setpoint. Process variability is defined inpercent as typically (2s/m), where m isthe set point or mean value of themeasured process variable and s isthe standard deviation of the processvariable.
Quick Opening Characteristic*: Aninherent flow characteristic in which amaximum flow coefficient is achievedwith minimal closure member travel(figure 1-2).
Relay: A device that acts as a poweramplifier. It takes an electrical, pneu-matic, or mechanical input signal andproduces an output of a large volumeflow of air or hydraulic fluid to the ac-tuator. The relay can be an internalcomponent of the positioner or a sep-arate valve accessory.
Resolution: The minimum possiblechange in input required to produce adetectable change in the output whenno reversal of the input takes place.Resolution is typically expressed as apercent of the input span.
Response Time: Usually measuredby a parameter that includes bothdead time and time constant. (SeeT63, Dead Time, and Time Constant.)When applied to the valve, it includesthe entire valve assembly.
Second-Order: A term that refers tothe dynamic relationship between theinput and output of a device. A sec-ond-order system or device is one thathas two energy storage devices thatcan transfer kinetic and potential ener-gy back and forth between them-selves, thus introducing the possibilityof oscillatory behavior and overshoot.
Sensor: A device that senses thevalue of the process variable and pro-vides a corresponding output signal toa transmitter. The sensor can be anintegral part of the transmitter, or itmay be a separate component.
Chapter 1. Introduction to Control Valves
6
Set Point: A reference value repre-senting the desired value of the pro-cess variable being controlled.
Shaft Wind-Up: A phenomenonwhere one end of a valve shaft turnsand the other does not. This typicallyoccurs in rotary-style valves where theactuator is connected to the valve clo-sure member by a relatively longshaft. While seal friction in the valveholds one end of the shaft in place,rotation of the shaft at the actuatorend is absorbed by twisting of theshaft until the actuator input transmitsenough force to overcome the friction.
Sizing (Valve): A systematic proce-dure designed to ensure the correctvalve capacity for a set of specifiedprocess conditions.
Stiction: (See Friction.)
T63 (Tee-63): A measure of deviceresponse. It is measured by applyinga small (usually 1-5%) step input tothe system. T63 is measured from thetime the step input is initiated to thetime when the system output reaches63% of the final steady-state value. Itis the combined total of the systemDead Time (Td) and the system TimeConstant (t). (See Dead Time andTime Constant.)
Time Constant: A time parameterthat normally applies to a first-orderelement. It is the time interval mea-sured from the first detectable re-sponse of the system to a small (usu-ally 0.25% - 5%) step input until thesystem output reaches 63% of its finalsteady-state value. (See T63.) Whenapplied to an open-loop process, thetime constant is usually designated as� (Tau). When applied to a closed-loopsystem, the time constant is usuallydesignated as λ (Lambda).
Transmitter: A device that sensesthe value of the process variable andtransmits a corresponding output sig-nal to the controller for comparisonwith the set point.
Travel*: The movement of the closuremember from the closed position to anintermediate or rated full open posi-tion.
Travel Indicator: A pointer and scaleused to externally show the position ofthe closure member typically withunits of opening percent of travel ordegrees of rotation.
Trim*: The internal components of avalve that modulate the flow of thecontrolled fluid.
Valve: (See Control Valve Assembly.)
Volume Booster: A stand-alonerelay is often referred to as a volumebooster or simply booster because itboosts, or amplifies, the volume of airsupplied to the actuator. (See Relay.)
Sliding-Stem ControlValve TerminologyThe following terminology applies tothe physical and operating character-istics of standard sliding-stem controlvalves with diaphragm or piston ac-tuators. Some of the terms, particular-ly those pertaining to actuators, arealso appropriate for rotary-shaft con-trol valves. Many of the definitionspresented are in accordance with ISAS75.05, Control Valve Terminology,although other popular terms are alsoincluded. Additional explanation isprovided for some of the more com-plex terms. Component part namesare called out on accompanying fig-ures 1-3 through 1-6. Separate sec-tions follow that define specificrotary-shaft control valve terminology,control valve functions and character-istics terminology, and other processcontrol terminology.
Actuator Spring: A spring, or groupof springs, enclosed in the yoke or ac-tuator casing that moves the actuatorstem in a direction opposite to thatcreated by diaphragm pressure.
Actuator Stem: The part that con-nects the actuator to the valve stem
Chapter 1. Introduction to Control Valves
7
Figure 1-3. Major Components of Typical Sliding-Stem Control Valve Assemblies
W0989
LOADING PRESSURE CONNECTION
DIAPHRAGM CASING
DIAPHRAGM AND STEMSHOWN IN UP POSITION
DIAPHRAGM PLATE
ACTUATOR SPRING
ACTUATOR STEM
SPRING SEAT
SPRING ADJUSTOR
STEM CONNECTORYOKE
TRAVEL INDICATOR
INDICATOR SCALE
W0363-1
BONNETGASKET
SPIRAL WOUND GASKET
CAGEGASKET
VALVE BODY
SEATRING
VALVE PLUG STEMPACKING FLANGE
ACTUATOR YOKE LOCKNUT
PACKINGPACKING BOX
BONNET
VALVE PLUG
CAGE
SEAT RING GASKET
PUSH-DOWN-
TO-CLOSE
VALVE BODY
ASSEMBLY
DIRECT-ACTING
ACTUATOR
W8486-3
COMPACT FIELD-REVERSIBLEMULTI-SPRING ACTUATOR
INTEGRATED POSITIONERMOUNTING
NAMUR POSITIONERMOUNTING CAPABILITY
ONE-PIECE SCREWEDPACKING FOLLOWER
CLAMPED BONNET DESIGN
STANDARD LIVE-LOADEDPACKING
INTEGRAL PNEUMATICPASSAGEWAYS
AIR-TO-OPEN
VALVE ASSEMBLY
Chapter 1. Introduction to Control Valves
8
Figure 1-4. Typical Reverse-Acting Diaphragm Actuator
DIAPHRAGM CASINGS
DIAPHRAGM ANDSTEM SHOWN INDOWN POSITION
DIAPHRAGMPLATE
LOADING PRESSURECONNECTION
ACTUATOR SPRING
ACTUATOR STEM
SPRING SEAT
SPRING ADJUSTOR
STEM CONNECTOR
YOKE
TRAVEL INDICATOR
INDICATOR SCALE
W0364-1/IL
Figure 1-5. Extension Bonnet
W0667/IL
and transmits motion (force) from theactuator to the valve.
Actuator Stem Extension: An ex-tension of the piston actuator stem toprovide a means of transmitting piston
Figure 1-6. Bellows Seal BonnetW6434/IL
motion to the valve positioner (figure1-7).
Actuator Stem Force: The net forcefrom an actuator that is available foractual positioning of the valve plug.
Chapter 1. Introduction to Control Valves
9
Figure 1-7. Typical Double-Acting Piston Actuator with Bias Spring
W7447-1/IIL
PISTON SEAL
CYLINDERCLOSURE SEAL
ACTUATOR STEM
STEM CONNECTOR
YOKE
TRAVEL INDICATOR
TRAVELINDICATOR SCALE
SEAL BUSHING
CYLINDER SEAL
ACTUATORSTEM SEAL
PISTON
CYLINDER
Angle Valve: A valve design in whichone port is co-linear with the valvestem or actuator, and the other port isat a right angle to the valve stem.(See also Globe Valve.)
Bellows Seal Bonnet: A bonnet thatuses a bellows for sealing againstleakage around the closure memberstem (figure 1-6).
Bonnet: The portion of the valve thatcontains the packing box and stemseal and can guide the stem. It pro-vides the principal opening to thebody cavity for assembly of internalparts or it can be an integral part ofthe valve body. It can also provide forthe attachment of the actuator to thevalve body. Typical bonnets arebolted, threaded, welded,pressure-seals, or integral with thebody. (This term is often used in refer-ring to the bonnet and its includedpacking parts. More properly, thisgroup of component parts should becalled the bonnet assembly.)
Bonnet Assembly: (Commonly Bon-net, more properly Bonnet Assembly):An assembly including the partthrough which a valve stem movesand a means for sealing against leak-age along the stem. It usually pro-vides a means for mounting the actua-tor and loading the packing assembly.
Bottom Flange: A part that closes avalve body opening opposite the bon-net opening. It can include a guidebushing and/or serve to allow reversalof the valve action.
Bushing: A device that supports and/or guides moving parts such as valvestems.
Cage: A part of a valve trim that sur-rounds the closure member and canprovide flow characterization and/or aseating surface. It also provides stabil-ity, guiding, balance, and alignment,and facilitates assembly of other partsof the valve trim. The walls of thecage contain openings that usuallydetermine the flow characteristic of
Chapter 1. Introduction to Control Valves
10
Figure 1-8. Characterized Cages for Globe-Style Valve Bodies
W0958/IL W0959/ILW0957/IL
QUICK OPENING EQUAL PERCENTAGELINEAR
the control valve. Various cage stylesare shown in figure 1-8.
Closure Member: The movable partof the valve that is positioned in theflow path to modify the rate of flowthrough the valve.
Closure Member Guide: That por-tion of a closure member that alignsits movement in either a cage, seatring, bonnet, bottom flange, or anytwo of these.
Cylinder: The chamber of a pistonactuator in which the piston moves(figure 1-7).
Cylinder Closure Seal: The sealingelement at the connection of the pis-ton actuator cylinder to the yoke.
Diaphragm: A flexible, pressure re-sponsive element that transmits forceto the diaphragm plate and actuatorstem.
Diaphragm Actuator: A fluid pow-ered device in which the fluid actsupon a flexible component, the dia-phragm.
Diaphragm Case: A housing, con-sisting of top and bottom section,used for supporting a diaphragm andestablishing one or two pressurechambers.
Diaphragm Plate: A plate concentricwith the diaphragm for transmittingforce to the actuator stem.
Direct Actuator: A diaphragm actua-tor in which the actuator stem extendswith increasing diaphragm pressure.
Extension Bonnet: A bonnet withgreater dimension between the pack-ing box and bonnet flange for hot orcold service.
Globe Valve: A valve with a linearmotion closure member, one or moreports, and a body distinguished by aglobular shaped cavity around the portregion. Globe valves can be furtherclassified as: two-way single-ported;two-way double-ported (figure 1-9);angle-style (figure 1-10); three-way(figure 1-11); unbalanced cage-guided(figure 1-3); and balance cage-guided(figure 1-12).
Lower Valve Body: A half housingfor internal valve parts having oneflow connection. The seat ring is nor-mally clamped between the uppervalve body and the lower valve bodyin split valve constructions.
Offset Valve: A valve constructionhaving inlet and outlet line connec-tions on different planes but 180 de-grees opposite each other.
Packing Box (Assembly): The partof the bonnet assembly used to sealagainst leakage around the closure
Chapter 1. Introduction to Control Valves
11
Figure 1-9. Reverse Double-PortedGlobe-Style Valve Body
W0467/IL
Figure 1-10. Flanged Angle-Style Con-trol Valve Body
W0971/IL
member stem. Included in the com-plete packing box assembly are vari-ous combinations of some or all of thefollowing component parts: packing,packing follower, packing nut, lanternring, packing spring, packing flange,packing flange studs or bolts, packingflange nuts, packing ring, packing wip-er ring, felt wiper ring, bellevillesprings, anti-extrusion ring. Individual
Figure 1-11. Three-Way Valve withBalanced Valve Plug
W0665/IL
Figure 1-12. Valve Body withCage-Style Trim, Balanced Valve
Plug, and Soft Seat
W0992/IL
packing parts are shown in figure1-13.
Piston: A movable pressure respon-sive element that transmits force tothe piston actuator stem (figure 1-7).
Piston Type Actuator: A fluid pow-ered device in which the fluid actsupon a movable piston to provide mo-tion to the actuator stem. Piston typeactuators (figure 1-7) are classified aseither double-acting, so that full power
Chapter 1. Introduction to Control Valves
12
Figure 1-13. Comprehensive Packing Material Arrangementsfor Globe-Style Valve Bodies
B2565 / IL LOCATION OF SACRIFICIAL ZINC WASHER,IF USED.
GRAPHITE PACKING ARRANGEMENTS
14A1849-E
1
12A7837-A
STANDARD
TFE V-RING
13A9775-E
can be developed in either direction,or as spring-fail so that upon loss ofsupply power, the actuator moves thevalve in the required direction of trav-el.
Plug: A term frequently used to referto the closure member.
Port: The flow control orifice of acontrol valve.
Retaining Ring: A split ring that isused to retain a separable flange on avalve body.
Reverse Actuator: A diaphragm ac-tuator in which the actuator stem re-tracts with increasing diaphragm pres-sure. Reverse actuators have a sealbushing (figure 1-4) installed in theupper end of the yoke to prevent leak-age of the diaphragm pressure alongthe actuator stem.
Rubber Boot: A protective device toprevent entrance of damaging foreignmaterial into the piston actuator sealbushing.
Seal Bushing: Top and bottom bush-ings that provide a means of sealing
the piston actuator cylinder againstleakage. Synthetic rubber O-rings areused in the bushings to seal the cylin-der, the actuator stem, and the actua-tor stem extension (figure 1-7).
Seat: The area of contact betweenthe closure member and its matingsurface that establishes valve shut-off.
Seat Load: The net contact force be-tween the closure member and seatwith stated static conditions. In prac-tice, the selection of an actuator for agiven control valve will be based onhow much force is required to over-come static, stem, and dynamic un-balance with an allowance made forseat load.
Seat Ring: A part of the valve bodyassembly that provides a seating sur-face for the closure member and canprovide part of the flow control orifice.
Separable Flange: A flange that fitsover a valve body flow connection. Itis generally held in place by means ofa retaining ring.
Spring Adjustor: A fitting, usuallythreaded on the actuator stem or into
Chapter 1. Introduction to Control Valves
13
the yoke, to adjust the spring com-pression.
Spring Seat: A plate to hold thespring in position and to provide a flatsurface for the spring adjustor to con-tact.
Static Unbalance: The net force pro-duced on the valve stem by the fluidpressure acting on the closure mem-ber and stem with the fluid at rest andwith stated pressure conditions.
Stem Connector: The device thatconnects the actuator stem to thevalve stem.
Trim: The internal components of avalve that modulate the flow of thecontrolled fluid. In a globe valve body,trim would typically include closuremember, seat ring, cage, stem, andstem pin.
Trim, Soft-Seated: Valve trim with anelastomeric, plastic or other readilydeformable material used either in theclosure component or seat ring to pro-vide tight shutoff with minimal actuatorforces.
Upper Valve Body: A half housingfor internal valve parts and having oneflow connection. It usually includes ameans for sealing against leakagealong the stem and provides a meansfor mounting the actuator on the splitvalve body.
Valve Body: The main pressureboundary of the valve that also pro-vides the pipe connecting ends, thefluid flow passageway, and supportsthe seating surfaces and the valveclosure member. Among the mostcommon valve body constructionsare: a) single-ported valve bodieshaving one port and one valve plug; b)double-ported valve bodies havingtwo ports and one valve plug; c)two-way valve bodies having two flowconnections, one inlet and one outlet;d) three-way valve bodies havingthree flow connections, two of whichcan be inlets with one outlet (for con-
verging or mixing flows), or one inletand two outlets (for diverging or di-verting flows). The term valve body, oreven just body, frequently is used inreferring to the valve body togetherwith its bonnet assembly and includedtrim parts. More properly, this group ofcomponents should be called thevalve body assembly.
Valve Body Assembly (CommonlyValve Body or Valve, more properlyValve Body Assembly): An assemblyof a valve, bonnet assembly, bottomflange (if used), and trim elements.The trim includes the closure member,which opens, closes, or partially ob-structs one or more ports.
Valve Plug: A term frequently inter-changed with plug in reference to theclosure member.
Valve Stem: In a linear motion valve,the part that connects the actuatorstem with the closure member.
Yoke: The structure that rigidly con-nects the actuator power unit to thevalve.
Rotary-Shaft Control ValveTerminology
The definitions that follow apply spe-cifically to rotary-shaft control valves.
Actuator Lever: Arm attached torotary valve shaft to convert linear ac-tuator stem motion to rotary force toposition disk or ball of rotary-shaftvalve. The lever normally is positivelyconnected to the rotary shaft by closetolerance splines or other means tominimize play and lost motion.
Ball, Full: The flow-controlling mem-ber of rotary-shaft control valves usinga complete sphere with a flow pas-sage through it. The flow passageequals or matches the pipe diameter.
Chapter 1. Introduction to Control Valves
14
W6213/ILECCENTRIC DISK VALVE
Figure 1-14. Typical Rotary-Shaft Control Valve Constructions
W5477/IL
W4920/IL
W4641
CONVENTIONAL DISK
BUTTERFLY VALVE
SEGMENTED BALL VALVE
CONTOURED DISK BUTTERFLY VALVE
Chapter 1. Introduction to Control Valves
15
Ball, Segmented: The flow-control-ling member of rotary shaft controlvalves using a partial sphere with aflow passage through it.
Ball, V-notch: The most commontype of segmented ball control valve.The V-notch ball includes a polishedor plated partial-sphere surface thatrotates against the seal ring through-out the travel range. The V-shapednotch in the ball permits wide range-ability and produces an equal percent-age flow characteristic.
Note:
The balls mentionedabove, and the diskswhich follow, perform afunction comparable tothe valve plug in aglobe-style controlvalve. That is, as theyrotate they vary the sizeand shape of the flow-stream by opening moreor less of the seal areato the flowing fluid.
Disk, Conventional: The symmetri-cal flow-controlling member used inthe most common varieties of butterflyrotary valves. High dynamic torquesnormally limit conventional disks to 60degrees maximum rotation in throttlingservice.
Disk, Dynamically Designed: A but-terfly valve disk contoured to reducedynamic torque at large increments ofrotation, thereby making it suitable forthrottling service with up to 90 de-grees of disk rotation.
Disk, Eccentric: Common name forvalve design in which the positioningof the valve shaft/disk connectionscauses the disk to take a slightly ec-centric path on opening. This allowsthe disk to be swung out of contactwith the seal as soon as it is opened,thereby reducing friction and wear.
Flangeless Valve: Valve style com-mon to rotary-shaft control valves.
Flangeless valves are held betweenANSI-class flanges by longthrough-bolts (sometimes also calledwafer-style valve bodies).
Plug, Eccentric: Style of rotary con-trol valve with an eccentrically rotatingplug which cams into and out of theseat, which reduces friction and wear.This style of valve has been wellsuited for erosive applications.
Reverse Flow: Flow from the shaftside over the back of the disk, ball, orplug. Some rotary-shaft control valvesare capable of handling flow equallywell in either direction. Other rotarydesigns might require modification ofactuator linkage to handle reverseflow.
Rod End Bearing: The connectionoften used between actuator stem andactuator lever to facilitate conversionof linear actuator thrust to rotary forcewith minimum of lost motion. Use of astandard reciprocating actuator on arotary-shaft valve body commonly re-quires linkage with two rod end bear-ings. However, selection of an actua-tor specifically designed forrotary-shaft valve service requiresonly one such bearing and thereby re-duces lost motion.
Rotary-Shaft Control Valve: A valvestyle in which the flow closure mem-ber (full ball, partial ball, disk or plug)is rotated in the flowstream to controlthe capacity of the valve (figure 1-14).
Seal Ring: The portion of arotary-shaft control valve assemblycorresponding to the seat ring of aglobe valve. Positioning of the disk orball relative to the seal ring deter-mines the flow area and capacity ofthe unit at that particular increment ofrotational travel. As indicated above,some seal ring designs permit bi-di-rectional flow.
Shaft: The portion of a rotary-shaftcontrol valve assembly correspondingto the valve stem of a globe valve.Rotation of the shaft positions the disk
Chapter 1. Introduction to Control Valves
16
or ball in the flowstream and therebycontrols capacity of the valve.
Sliding Seal: The lower cylinder sealin a pneumatic piston-style actuatordesigned for rotary valve service. Thisseal permits the actuator stem tomove both vertically and laterally with-out leakage of lower cylinder pres-sure.
Standard Flow: For thoserotary-shaft control valves having aseparate seal ring or flow ring, theflow direction in which fluid enters thevalve body through the pipeline adja-cent to the seal ring and exits from theside opposite the seal ring. Some-times called forward flow. (See alsoReverse Flow.)
Trunnion Mounting: A style ofmounting the disk or ball on the valveshaft or stub shaft with two bearingsdiametrically opposed.
Control Valve Functionsand CharacteristicsTerminologyBench Set: The calibration of the ac-tuator spring range of a control valveto account for the in-service processforces.
Capacity: Rate of flow through avalve under stated conditions.
Clearance Flow: That flow below theminimum controllable flow with theclosure member not seated.
Diaphragm Pressure Span: Differ-ence between the high and low valuesof the diaphragm pressure range. Thiscan be stated as an inherent orinstalled characteristic.
Double-Acting Actuator: An actua-tor in which power is supplied in eitherdirection.
Dynamic Unbalance: The net forceproduced on the valve plug in anystated open position by the fluid pres-sure acting upon it.
Effective Area: In a diaphragm ac-tuator, the effective area is that part ofthe diaphragm area that is effective inproducing a stem force. The effectivearea of a diaphragm might change asit is stroked, usually being a maximumat the start and a minimum at the endof the travel range. Molded dia-phragms have less change in effectivearea than flat sheet diaphragms; thus,molded diaphragms are recom-mended.
Equal Percentage Flow Character-istic: (See Process Control Terminol-ogy: Equal Percentage Flow Charac-teristic.)
Fail-Closed: A condition wherein thevalve closure member moves to aclosed position when the actuating en-ergy source fails.
Fail-Open: A condition wherein thevalve closure member moves to anopen position when the actuating en-ergy source fails.
Fail-Safe: A characteristic of a valveand its actuator, which upon loss ofactuating energy supply, will cause avalve closure member to be fullyclosed, fully open, or remain in thelast position, whichever position is de-fined as necessary to protect the pro-cess. Fail-safe action can involve theuse of auxiliary controls connected tothe actuator.
Flow Characteristic: Relationshipbetween flow through the valve andpercent rated travel as the latter isvaried from 0 to 100 percent. Thisterm should always be designated aseither inherent flow characteristic orinstalled flow characteristic.
Flow Coefficient (Cv): A constant(Cv) related to the geometry of avalve, for a given travel, that can beused to establish flow capacity. It isthe number of U.S. gallons per minuteof 60�F water that will flow through avalve with a one pound per squareinch pressure drop.
High-Recovery Valve: A valve de-sign that dissipates relatively little
Chapter 1. Introduction to Control Valves
17
flow-stream energy due to streamlinedinternal contours and minimal flow tur-bulence. Therefore, pressure down-stream of the valve vena contracta re-covers to a high percentage of its inletvalue. Straight-through flow valves,such as rotary-shaft ball valves, aretypically high-recovery valves.
Inherent Diaphragm PressureRange: The high and low values ofpressure applied to the diaphragm toproduce rated valve plug travel withatmospheric pressure in the valvebody. This range is often referred toas a bench set range because it willbe the range over which the valve willstroke when it is set on the workbench.
Inherent Flow Characteristic: Therelationship between the flow rate andthe closure member travel as it ismoved from the closed position torated travel with constant pressuredrop across the valve.
Installed Diaphragm PressureRange: The high and low values ofpressure applied to the diaphragm toproduce rated travel with stated condi-tions in the valve body. It is becauseof the forces acting on the closuremember that the inherent diaphragmpressure range can differ from theinstalled diaphragm pressure range.
Installed Flow Characteristic: Therelationship between the flow rate andthe closure member travel as it ismoved from the closed position torated travel as the pressure dropacross the valve is influenced by thevarying process conditions.
Leakage: (See Seat Leakage.)
Linear Flow Characteristic: (SeeProcess Control Terminology: LinearCharacteristic.)
Low-Recovery Valve: A valve de-sign that dissipates a considerableamount of flowstream energy due toturbulence created by the contours ofthe flowpath. Consequently, pressure
downstream of the valve vena con-tracta recovers to a lesser percentageof its inlet value than is the case witha valve having a more streamlinedflowpath. Although individual designsvary, conventional globe-style valvesgenerally have low pressure recoverycapability.
Modified Parabolic Flow Character-istic: An inherent flow characteristicthat provides equal percent character-istic at low closure member travel andapproximately a linear characteristicfor upper portions of closure membertravel.
Normally Closed Valve: (SeeFail-Closed.)
Normally Open Valve: (SeeFail-Open.)
Push-Down-to-Close Construction:A globe-style valve construction inwhich the closure member is locatedbetween the actuator and the seatring, such that extension of the actua-tor stem moves the closure membertoward the seat ring, finally closing thevalve (figure 1-3). The term can alsobe applied to rotary-shaft valveconstructions where linear extensionof the actuator stem moves the ball ordisk toward the closed position. (Alsocalled direct acting.)
Push-Down-to-Open Construction:A globe-style valve construction inwhich the seat ring is located betweenthe actuator and the closure member,so that extension of the actuator stemmoves the closure member from theseat ring, opening the valve. The termcan also be applied to rotary-shaftvalve constructions where linear ex-tension of the actuator stem movesthe ball or disk toward the open posi-tion. (Also called reverse acting.)
Quick Opening Flow Characteristic:(See Process Control Terminology:Quick Opening Characteristic.)
Rangeability: The ratio of the largestflow coefficient (Cv) to the smallestflow coefficient (Cv) within which the
Chapter 1. Introduction to Control Valves
18
deviation from the specified flow char-acteristic does not exceed the statedlimits. A control valve that still does agood job of controlling when flow in-creases to 100 times the minimumcontrollable flow has a rangeability of100 to 1. Rangeability can also be ex-pressed as the ratio of the maximumto minimum controllable flow rates.
Rated Flow Coefficient (Cv): Theflow coefficient (Cv) of the valve atrated travel.
Rated Travel: The distance of move-ment of the closure member from theclosed position to the rated full-openposition. The rated full-open positionis the maximum opening recom-mended by the manufacturers.
Relative Flow Coefficient: The ratioof the flow coefficient (Cv) at a statedtravel to the flow coefficient (Cv) atrated travel.
Seat Leakage: The quantity of fluidpassing through a valve when thevalve is in the fully closed positionwith pressure differential and tempera-ture as specified. (ANSI leakage clas-sifications are outlined in Chapter 5.)
Spring Rate: The force change perunit change in length of a spring. Indiaphragm control valves, the springrate is usually stated in pounds forceper inch compression.
Stem Unbalance: The net force pro-duced on the valve stem in any posi-tion by the fluid pressure acting uponit.
Vena Contracta: The portion of aflow stream where fluid velocity is atits maximum and fluid static pressureand the cross-sectional area are attheir minimum. In a control valve, thevena contracta normally occurs justdownstream of the actual physical re-striction.
Other Process ControlTerminologyThe following terms and definitionsnot previously defined are frequentlyencountered by people associatedwith control valves, instrumentation,and accessories. Some of the terms(indicated with an asterisk) are quotedfrom the ISA standard, Process Instru-mentation Terminology, ISA 51.1. Oth-ers included are also popularly usedthroughout the control valve industry.
ANSI: Abbreviation for American Na-tional Standards Institute.
API: Abbreviation for American Pe-troleum Institute.
ASME: Abbreviation for AmericanSociety of Mechanical Engineers.
ASTM: Abbreviation for AmericanSociety for Testing and Materials.
Automatic Control System*: A con-trol system that operates without hu-man intervention.
Bode Diagram*: A plot of log ampli-tude ratio and phase angle values ona log frequency base for a transferfunction (figure 1-15). It is the mostcommon form of graphically present-ing frequency response data.
Calibration Curve*: A graphical rep-resentation of the calibration report(figure 1-15). Steady state output of adevice plotted as a function of itssteady state input. The curve is usual-ly shown as percent output span ver-sus percent input span.
Calibration Cycle*: The applicationof known values of the measured vari-able and the recording of correspond-ing values of output readings, over therange of the instrument, in ascendingand descending directions (figure1-15). A calibration curve obtained byvarying the input of a device in bothincreasing and decreasing directions.It is usually shown as percent outputspan versus percent input span andprovides a measurement of hystere-sis.
Chapter 1. Introduction to Control Valves
19
Figure 1-15. Graphic Representation of Various Control Terms
Chapter 1. Introduction to Control Valves
20
Clearance Flow: That flow below theminimum controllable flow with theclosure general member not seated.
Controller*: A device that operatesautomatically to regulate a controlledvariable.
Enthalpy: A thermodynamic quantitythat is the sum of the internal energyof a body and the product of its vol-ume multiplied by the pressure: H = U+ pV. (Also called the heat content.)
Entropy: The theoretical measure ofenergy that cannot be transformedinto mechanical work in a thermody-namic system.
Feedback Signal*: The return signalthat results from a measurement ofthe directly controlled variable. For acontrol valve with a positioner, the re-turn signal is usually a mechanical in-dication of closure member stem posi-tion that is fed back into the positioner.
FCI: Abbreviation for Fluid ControlsInstitute.
Frequency Response Characteris-tic*: The frequency-dependent rela-tion, in both amplitude and phase, be-tween steady-state sinusoidal inputsand the resulting fundamental sinusoi-dal outputs. Output amplitude andphase shift are observed as functionsof the input test frequency and used todescribe the dynamic behavior of thecontrol device.
Hardness: Resistance of metal toplastic deformation, usually by in-dentation. Resistance of plastics andrubber to penetration of an indentorpoint into its surface.
Hunting*: An undesirable oscillationof appreciable magnitude, prolongedafter external stimuli disappear.Sometimes called cycling or limitcycle, hunting is evidence of operationat or near the stability limit. In controlvalve applications, hunting would ap-pear as an oscillation in the loadingpressure to the actuator caused by
instability in the control system or thevalve positioner.
Hysteresis: A retardation of an effectwhen the forces acting upon a bodyare changed (as if from viscosity orinternal friction).
ISA: Abbreviation for the InstrumentSociety of America. Now recognizedas the International Society for Mea-surement and Control.
Instrument Pressure: The outputpressure from an automatic controllerthat is used to operate a control valve.
Loading Pressure: The pressureemployed to position a pneumatic ac-tuator. This is the pressure that actual-ly works on the actuator diaphragm orpiston and it can be the instrumentpressure if a valve positioner is notused.
NACE: Used to stand for NationalAssociation of Corrosion Engineers.As the scope of the organization be-came international, the name waschanged to NACE International.NACE is no longer an abbreviation.
OSHA: Abbreviation for OccupationalSafety and Health Act. (U.S.A.)
Operating Medium: This is the fluid,generally air or gas, used to supplythe power for operation of valve posi-tioner or automatic controller.
Operative Limits*: The range of op-erating conditions to which a devicecan be subjected without permanentimpairment of operating characteris-tics.
Range: The region between the limitswithin which a quantity is measured,received, or transmitted, expressed bystating the lower and upper range val-ues (for example: 3 to 15 psi; -40 to+212�F; -40 to +100�C).
Repeatability*: The closeness ofagreement among a number of con-secutive measurements of the outputfor the same value of the input underthe same operating conditions, ap-
Chapter 1. Introduction to Control Valves
21
proaching from the same direction, forfull range traverses. It is usually mea-sured as a non-repeatability and ex-pressed as repeatability in percent ofspan. It does not include hyesteresis(figure 1-15).
Sensitivity*: The ratio of the changein output magnitude to the change ofthe input that causes it after thesteady-state has been reached.
Signal*: A physical variable, one ormore parameters of which carry infor-mation about another variable the sig-nal represents.
Signal Amplitude Sequencing (SplitRanging)*: Action in which two ormore signals are generated or two ormore final controlling elements are ac-tuated by and input signal, each oneresponding consecutively, with or
without overlap, to the magnitude ofthat input signal (figure 1-15).
Span*: The algebraic difference be-tween the upper and lower range val-ues (for example: Range = 0 to150�F; Span = 150�F; Range = 3 to15 psig, Span = 12 psig).
Stiction: the force required to causeone body in contact with another tobegin to move.
Supply Pressure*: The pressure atthe supply port of a device. Commonvalues of control valve supply pres-sure are 20 psig for a 3 to 15 psigrange and 35 psig for a 6 to 30 psigrange.
Zero Error*: Error of a device operat-ing under specified conditions of usewhen the input is at the lower rangevalue. It is usually expressed as per-cent of ideal span.
Chapter 1. Introduction to Control Valves
22
23
Chapter 2
Control Valve Performance
In today’s dynamic business environ-ment, manufacturers are under ex-treme economic pressures. Marketglobalization is resulting in intensepressures to reduce manufacturingcosts to compete with lower wagesand raw material costs of emergingcountries. Competition exists betweeninternational companies to provide thehighest quality products and to maxi-mize plant throughputs with fewer re-sources, although meeting everchanging customer needs. Thesemarketing challenges must be met al-though fully complying with public andregulatory policies.
Process VariabilityTo deliver acceptable returns to theirshareholders, international industryleaders are realizing they must reduceraw material and scrap costs while in-creasing productivity. Reducing pro-
cess variability in the manufacturingprocesses through the application ofprocess control technology is recog-nized as an effective method to im-prove financial returns and meet glob-al competitive pressures.
The basic objective of a company is tomake a profit through the productionof a quality product. A quality productconforms to a set of specifications.Any deviation from the establishedspecification means lost profit due toexcessive material use, reprocessingcosts, or wasted product. Thus, alarge financial impact is obtainedthrough improving process control.Reducing process variability throughbetter process control allows optimiza-tion of the process and the productionof products right the first time.
The non-uniformity inherent in the rawmaterials and processes of productionare common causes of variation thatproduce a variation of the process
Chapter 2. Control Valve Performance
24
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Figure 2-1. Process Variability
2-Sigma 2-Sigma
variable both above and below the setpoint. A process that is in control, withonly the common causes of variationpresent, typically follows abell-shaped normal distribution (figure2-1).
A statistically derived band of valueson this distribution, called the +/-2 sig-ma band, describes the spread of pro-cess variable deviations from the setpoint. This band is the variability of theprocess. It is a measure of how tightlythe process is being controlled. Pro-cess Variability (see definition inChapter 1) is a precise measure oftightness of control and is expressedas a percentage of the set point.
If a product must meet a certain low-er-limit specification, for example, theset point needs to be established at a2 sigma value above this lower limit.Doing so will ensure that all the prod-uct produced at values to the right ofthe lower limit will meet the qualityspecification.
The problem, however, is that moneyand resources are being wasted bymaking a large percentage of theproduct to a level much greater thanrequired by the specification (see up-per distribution in figure 2-1).
The most desirable solution is to re-duce the spread of the deviation aboutthe set point by going to a controlvalve that can produce a smaller sig-ma (see lower distribution in figure2-1).
Reducing process variability is a keyto achieving business goals. Mostcompanies realize this, and it is notuncommon for them to spendhundreds of thousands of dollars oninstrumentation to address the prob-lem of process variability reduction.
Unfortunately, the control valve isoften overlooked in this effort becauseits impact on dynamic performance isnot realized. Extensive studies of con-trol loops indicate as many as 80% ofthe loops did not do an adequate jobof reducing process variability. Fur-thermore, the control valve was foundto be a major contributor to this prob-lem for a variety of reasons.
To verify performance, manufacturersmust test their products under dynam-ic process conditions. These are typi-cally performed in a flow lab in actualclosed-loop control (figure 2-2). Evalu-ating control valve assemblies underclosed-loop conditions provides theonly true measure of variability perfor-mance. Closed-loop performance dataproves significant reductions in pro-
Chapter 2. Control Valve Performance
25
Figure 2-2. Performance Test LoopW9127
cess variability can be achieved bychoosing the right control valve for theapplication.
The ability of control valves to reduceprocess variability depends uponmany factors. More than one isolatedparameter must be considered. Re-search within the industry has foundthe particular design features of thefinal control element, including thevalve, actuator, and positioner, arevery important in achieving good pro-cess control under dynamic condi-tions. Most importantly, the controlvalve assembly must be optimized ordeveloped as a unit. Valve compo-nents not designed as a complete as-sembly typically do not yield the bestdynamic performance. Some of themost important design considerationsinclude:
� Dead band
� Actuator/positioner design
� Valve response time
� Valve type and sizing
Each of these design features will beconsidered in this chapter to provideinsight into what constitutes a superiorvalve design.
Dead BandDead band is a major contributor toexcess process variability, and controlvalve assemblies can be a primarysource of dead band in an instrumen-tation loop due to a variety of causessuch as friction, backlash, shaftwind-up, relay or spool valve deadzone, etc..
Dead band is a general phenomenonwhere a range or band of controlleroutput (CO) values fails to produce achange in the measured process vari-able (PV) when the input signal re-verses direction. (See definitions ofthese terms in Chapter 1.) When aload disturbance occurs, the processvariable (PV) deviates from the setpoint. This deviation initiates a correc-tive action through the controller and
Chapter 2. Control Valve Performance
26
back through the process. However,an initial change in controller outputcan produce no corresponding correc-tive change in the process variable.Only when the controller output haschanged enough to progress throughthe dead band does a correspondingchange in the process variable occur.
Any time the controller output re-verses direction, the controller signalmust pass through the dead band be-fore any corrective change in the pro-cess variable will occur. The presenceof dead band in the process ensuresthe process variable deviation fromthe set point will have to increase untilit is big enough to get through thedead band. Only then can a correctiveaction occur.
Dead band has many causes, but fric-tion and backlash in the control valve,along with shaft wind-up in rotaryvalves, and relay dead zone are someof the more common forms. Becausemost control actions for regulatorycontrol consist of small changes (1%or less), a control valve with excessivedead band might not even respond tomany of these small changes. Awell-engineered valve should respondto signals of 1% or less to provideeffective reduction in process variabili-ty. However, it is not uncommon forsome valves to exhibit dead band asgreat as 5% or more. In a recent plantaudit, 30% of the valves had deadbands in excess of 4%. Over 65% ofthe loops audited had dead bandsgreater than 2%.
Figure 2-3 shows just how dramaticthe combined effects of dead bandcan be. This diagram represents anopen-loop test of three different con-trol valves under normal process con-ditions. The valves are subjected to aseries of step inputs which range from0.5% to 10%. Step tests under flowingconditions such as these are essentialbecause they allow the performanceof the entire valve assembly to beevaluated, rather than just the valveactuator assembly as would be the
Figure 2-3. Effect of Dead Band onValve Performance
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case under most bench test condi-tions.
Some performance tests on a valveassembly compare only the actuatorstem travel versus the input signal.This is misleading because it ignoresthe performance of the valve itself.
It is critical to measure dynamic per-formance of a valve under flowingconditions so the change in processvariable can be compared to thechange in valve assembly input sig-nal. It matters little if only the valvestem changes in response to achange in valve input because if thereis no corresponding change in thecontrolled variable, there will be nocorrection to the process variable.
In all three valve tests (figure 2-3), theactuator stem motion changes fairlyfaithfully in response to the input sig-nal changes. On the other hand, thereis a dramatic difference in each ofthese valve’s ability to change the flowin response to an input signal change.
For Valve A the process variable (flowrate) responds well to input signals aslow as 0.5. Valve B requires input sig-
Chapter 2. Control Valve Performance
27
nal changes as great as 5% before itbegins responding faithfully to each ofthe input signal steps. Valve C is con-siderably worse, requiring signalchanges as great as 10% before it be-gins to respond faithfully to each ofthe input signal steps. The ability ofeither Valve B or C to improve pro-cess variability is very poor.
Friction is a major cause of dead bandin control valves. Rotary valves areoften very susceptible to frictioncaused by the high seat loads re-quired to obtain shut-off with someseal designs. Because of the highseal friction and poor drive train stiff-ness, the valve shaft winds up anddoes not translate motion to the con-trol element. As a result, an improper-ly designed rotary valve can exhibitsignificant dead band that clearly hasa detrimental effect on process vari-ability.
Manufacturers usually lubricate rotaryvalve seals during manufacture, butafter only a few hundred cycles thislubrication wears off. In addition, pres-sure-induced loads also cause sealwear. As a result, the valve frictioncan increase by 400% or more forsome valve designs. This illustratesthe misleading performance conclu-sions that can result from evaluatingproducts using bench type data beforethe torque has stabilized. Valves Band C (figure 2-3) show the devastat-ing effect these higher friction torquefactors can have on a valve’s perfor-mance.
Packing friction is the primary sourceof friction in sliding-stem valves. Inthese types of valves, the measuredfriction can vary significantly betweenvalve styles and packing arrange-ments.
Actuator style also has a profound im-pact on control valve assembly fric-tion. Generally, spring-and-diaphragmactuators contribute less friction to thecontrol valve assembly than piston ac-tuators. An additional advantage ofspring-and-diaphragm actuators is
that their frictional characteristics aremore uniform with age. Piston actua-tor friction probably will increase sig-nificantly with use as guide surfacesand the O-rings wear, lubrication fails,and the elastomer degrades. Thus, toensure continued good performance,maintenance is required more oftenfor piston actuators than forspring-and-diaphragm actuators. Ifthat maintenance is not performed,process variability can suffer dramati-cally without the operator’s knowl-edge.
Backlash (see definition in Chapter 1)is the name given to slack, or loose-ness of a mechanical connection. Thisslack results in a discontinuity of mo-tion when the device changes direc-tion. Backlash commonly occurs ingear drives of various configurations.Rack-and-pinion actuators are particu-larly prone to dead band due to back-lash. Some valve shaft connectionsalso exhibit dead band effects. Splineconnections generally have much lessdead band than keyed shafts ordouble-D designs.
While friction can be reduced signifi-cantly through good valve design, it isa difficult phenomenon to eliminateentirely. A well-engineered controlvalve should be able to virtually elimi-nate dead band due to backlash andshaft wind-up.
For best performance in reducing pro-cess variability, the total dead band forthe entire valve assembly should be1% or less. Ideally, it should be as lowas 0.25%.
Actuator-Positioner DesignActuator and positioner design mustbe considered together. The combina-tion of these two pieces of equipmentgreatly affects the static performance(dead band), as well as the dynamicresponse of the control valve assem-bly and the overall air consumption ofthe valve instrumentation.
Positioners are used with the majorityof control valve applications specified
Chapter 2. Control Valve Performance
28
today. Positioners allow for precisepositioning accuracy and faster re-sponse to process upsets when usedwith a conventional digital control sys-tem. With the increasing emphasisupon economic performance of pro-cess control, positioners should beconsidered for every valve applicationwhere process optimization is impor-tant.
The most important characteristic of agood positioner for process variabilityreduction is that it be a high gain de-vice. Positioner gain is composed oftwo parts: the static gain and the dy-namic gain.
Static gain is related to the sensitivityof the device to the detection of small(0.125% or less) changes of the inputsignal. Unless the device is sensitiveto these small signal changes, it can-not respond to minor upsets in theprocess variable. This high static gainof the positioner is obtained through apreamplifier, similar in function to thepreamplifier contained in high fidelitysound systems. In many pneumaticpositioners, a nozzle-flapper or similardevice serves as this high static gainpreamplifier.
Once a change in the process vari-able has been detected by the highstatic gain positioner preamplifier, thepositioner must then be capable ofmaking the valve closure membermove rapidly to provide a timely cor-rective action to the process variable.This requires much power to make theactuator and valve assembly movequickly to a new position. In otherwords, the positioner must rapidlysupply a large volume of air to the ac-tuator to make it respond promptly.The ability to do this comes from thehigh dynamic gain of the positioner.Although the positioner preamplifiercan have high static gain, it typicallyhas little ability to supply the powerneeded. Thus, the preamplifier func-tion must be supplemented by a highdynamic gain power amplifier that
supplies the required air flow as rapid-ly as needed. This power amplifierfunction is typically provided by arelay or a spool valve.
Spool valve positioners are relativelypopular because of their simplicity.Unfortunately, many spool valve posi-tioners achieve this simplicity by omit-ting the high gain preamplifier from thedesign. The input stage of these posi-tioners is often a low static gain trans-ducer module that changes the inputsignal (electric or pneumatic) intomovement of the spool valve, but thistype of device generally has low sen-sitivity to small signal changes. Theresult is increased dead time andoverall response time of the controlvalve assembly.
Some manufacturers attempt to com-pensate for the lower performance ofthese devices by using spool valveswith enlarged ports and reduced over-lap of the ports. This increases the dy-namic power gain of the device, whichhelps performance to some extent if itis well matched to the actuator, but italso dramatically increases the airconsumption of these high gain spoolvalves. Many high gain spool valvepositioners have static instrument airconsumption five times greater thantypical high performance two-stagepositioners.
Typical two-stage positioners usepneumatic relays at the power amplifi-er stage. Relays are preferred be-cause they can provide high powergain that gives excellent dynamic per-formance with minimal steady-stateair consumption. In addition, they areless subject to fluid contamination.
Positioner designs are changing dra-matically, with microprocessor devicesbecoming increasingly popular (seeChapter 4). Thesemicroprocessor-based positionersprovide dynamic performance equal tothe best conventional two-stage pneu-matic positioners. They also providevalve monitoring and diagnostic capa-bilities to help ensure that initial good
Chapter 2. Control Valve Performance
29
performance does not degrade withuse.
In summary, high-performance posi-tioners with both high static and dy-namic gain provide the best overallprocess variability performance forany given valve assembly.
Valve Response Time
For optimum control of many pro-cesses, it is important that the valvereach a specific position quickly. Aquick response to small signalchanges (1% or less) is one of themost important factors in providing op-timum process control. In automatic,regulatory control, the bulk of the sig-nal changes received from the control-ler are for small changes in position. Ifa control valve assembly can quicklyrespond to these small changes, pro-cess variability will be improved.
Valve response time is measured by aparameter called T63 (Tee-63); (seedefinitions in Chapter 1). T63 is thetime measured from initiation of theinput signal change to when the out-put reaches 63% of the correspondingchange. It includes both the valve as-sembly dead time, which is a statictime, and the dynamic time of thevalve assembly. The dynamic time isa measure of how long the actuatortakes to get to the 63% point once itstarts moving.
Dead band, whether it comes fromfriction in the valve body and actuatoror from the positioner, can significantlyaffect the dead time of the valve as-sembly. It is important to keep thedead time as small as possible. Gen-erally dead time should be no morethan one-third of the overall valve re-sponse time. However, the relativerelationship between the dead timeand the process time constant is criti-cal. If the valve assembly is in a fastloop where the process time constantapproaches the dead time, the deadtime can dramatically affect loop per-formance. On these fast loops, it is
critical to select control equipmentwith dead time as small as possible.
Also, from a loop tuning point of view,it is important that the dead time berelatively consistent in both strokingdirections of the valve. Some valveassembly designs can have deadtimes that are three to five timeslonger in one stroking direction thanthe other. This type of behavior istypically induced by the asymmetricbehavior of the positioner design, andit can severely limit the ability to tunethe loop for best overall performance.
Once the dead time has passed andthe valve begins to respond, the re-mainder of the valve response timecomes from the dynamic time of thevalve assembly. This dynamic timewill be determined primarily by the dy-namic characteristics of the positionerand actuator combination. These twocomponents must be carefullymatched to minimize the total valveresponse time. In a pneumatic valveassembly, for example, the positionermust have a high dynamic gain tominimize the dynamic time of thevalve assembly. This dynamic gaincomes mainly from the power amplifi-er stage in the positioner. In otherwords, the faster the positioner relayor spool valve can supply a large vol-ume of air to the actuator, the fasterthe valve response time will be. How-ever, this high dynamic gain poweramplifier will have little effect on thedead time unless it has some inten-tional dead band designed into it toreduce static air consumption. Ofcourse, the design of the actuator sig-nificantly affects the dynamic time. Forexample, the greater the volume ofthe actuator air chamber to be filled,the slower the valve response time.
At first, it might appear that the solu-tion would be to minimize the actuatorvolume and maximize the positionerdynamic power gain, but it is really notthat easy. This can be a dangerouscombination of factors from a stabilitypoint of view. Recognizing that the po-sitioner/actuator combination is its
Chapter 2. Control Valve Performance
30
own feedback loop, it is possible tomake the positioner/actuator loop gaintoo high for the actuator design beingused, causing the valve assembly togo into an unstable oscillation. In addi-tion, reducing the actuator volume hasan adverse affect on the thrust-to-fric-tion ratio, which increases the valveassembly dead band resulting in in-creased dead time.
If the overall thrust-to-friction ratio isnot adequate for a given application,one option is to increase the thrust ca-pability of the actuator by using thenext size actuator or by increasing thepressure to the actuator. This higherthrust-to-friction ratio reduces deadband, which should help to reduce thedead time of the assembly. However,both of these alternatives mean that agreater volume of air needs to be sup-plied to the actuator. The tradeoff is apossible detrimental effect on thevalve response time through in-creased dynamic time.
One way to reduce the actuator airchamber volume is to use a piston ac-tuator rather than a spring-and-dia-phragm actuator, but this is not a pan-acea. Piston actuators usually havehigher thrust capability thanspring-and-diaphragm actuators, butthey also have higher friction, whichcan contribute to problems with valveresponse time. To obtain the requiredthrust with a piston actuator, it is usu-ally necessary to use a higher airpressure than with a diaphragm ac-tuator, because the piston typicallyhas a smaller area. This means that alarger volume of air needs to be sup-plied with its attendant ill effects onthe dynamic time. In addition, pistonactuators, with their greater number ofguide surfaces, tend to have higherfriction due to inherent difficulties inalignment, as well as friction from theO-ring. These friction problems alsotend to increase over time. Regard-less of how good the O-rings are ini-tially, these elastomeric materials willdegrade with time due to wear and
other environmental conditions. Like-wise wear on the guide surfaces willincrease the friction, and depletion ofthe lubrication will occur. These fric-tion problems result in a greater pistonactuator dead band, which will in-crease the valve response timethrough increased dead time.
Instrument supply pressure can alsohave a significant impact on dynamicperformance of the valve assembly.For example, it can dramatically affectthe positioner gain, as well as overallair consumption.
Fixed-gain positioners have generallybeen optimized for a particular supplypressure. This gain, however, canvary by a factor of two or more over asmall range of supply pressures. Forexample, a positioner that has beenoptimized for a supply pressure of 20psig might find its gain cut in halfwhen the supply pressure is boostedto 35 psig.
Supply pressure also affects the vol-ume of air delivered to the actuator,which in turn determines strokingspeed. It is also directly linked to airconsumption. Again, high-gain spoolvalve positioners can consume up tofive times the amount of air requiredfor more efficient high-performance,two-stage positioners that use relaysfor the power amplification stage.
To minimize the valve assembly deadtime, minimize the dead band of thevalve assembly, whether it comesfrom friction in the valve seal design,packing friction, shaft wind-up, actua-tor, or positioner design. As indicated,friction is a major cause of dead bandin control valves. On rotary valvestyles, shaft wind-up (see definition inChapter 1) can also contribute signifi-cantly to dead band. Actuator stylealso has a profound impact on controlvalve assembly friction. Generally,spring-and-diaphragm actuators con-tribute less friction to the control valveassembly than piston actuators overan extended time. As mentioned, thisis caused by the increasing friction
Chapter 2. Control Valve Performance
31
from the piston O-ring, misalignmentproblems, and failed lubrication.
Having a positioner design with a highstatic gain preamplifier can make asignificant difference in reducing deadband. This can also make a significantimprovement in the valve assemblyresolution (see definition in Chapter1). Valve assemblies with dead bandand resolution of 1% or less are nolonger adequate for many processvariability reduction needs. Many pro-cesses require the valve assembly tohave dead band and resolution as lowas 0.25%, especially where the valveassembly is installed in a fast processloop.
One of the surprising things to comeout of many industry studies on valveresponse time has been the change inthinking about spring-and-diaphragmactuators versus piston actuators. Ithas long been a misconception in theprocess industry that piston actuatorsare faster than spring-and-diaphragmactuators. Research has shown this tobe untrue for small signal changes.
This mistaken belief arose from manyyears of experience with testingvalves for stroking time. A strokingtime test is normally conducted bysubjecting the valve assembly to a100% step change in the input signaland measuring the time it takes thevalve assembly to complete its fullstroke in either direction.
Although piston-actuated valves usu-ally do have faster stroking times thanmost spring-and-diaphragm actuatedvalves, this test does not indicatevalve performance in an actual pro-cess control situation. In normal pro-cess control applications, the valve israrely required to stroke through itsfull operating range. Typically, thevalve is only required to respond with-
in a range of 0.25% to 2% change invalve position. Extensive testing ofvalves has shown that spring-and-dia-phragm valve assemblies consistentlyoutperform piston actuated valves onsmall signal changes, which are morerepresentative of regulatory processcontrol applications. Higher friction inthe piston actuator is one factor thatplays a role in making them less re-sponsive to small signals thanspring-and-diaphragm actuators.
Selecting the proper valve, actuator,positioner combination is not easy. Itis not simply a matter of finding acombination that is physically compat-ible. Good engineering judgment mustgo into the practice of valve assemblysizing and selection to achieve thebest dynamic performance from theloop.
Figure 2-4 shows the dramatic differ-ences in dead time and overall T63 re-sponse time caused by differences invalve assembly design.
Valve Type AndCharacterizationThe style of valve used and the sizingof the valve can have a large impacton the performance of the controlvalve assembly in the system. While avalve must be of sufficient size topass the required flow under all pos-sible contingencies, a valve that is toolarge for the application is a detrimentto process optimization.
Flow capacity of the valve is also re-lated to the style of valve through theinherent characteristic of the valve.The inherent characteristic (see defini-tion in Chapter 1) is the relationshipbetween the valve flow capacity andthe valve travel when the differentialpressure drop across the valve is heldconstant.
Chapter 2. Control Valve Performance
32
VALVE RESPONSE TIME
STEPSIZE
T(d)SEC.
T63SEC.
ENTECH SPEC. 4” VALVE SIZE % �0.2 �0.6
Valve A (Fisher V150HD/1052(33)/3610J)
VALVE ACTION / OPENING 2 0.25 0.34
VALVE ACTION / CLOSING −2 0.50 0.74
VALVE ACTION / OPENING 5 0.16 0.26
VALVE ACTION / CLOSING −5 0.22 0.42
VALVE ACTION / OPENING 10 0.19 0.33
VALVE ACTION / CLOSING −10 0.23 0.46
Valve B
VALVE ACTION / OPENING 2 5.61 7.74
VALVE ACTION / CLOSING −2 0.46 1.67
VALVE ACTION / OPENING 5 1.14 2.31
VALVE ACTION / CLOSING −5 1.04 2
VALVE ACTION / OPENING 10 0.42 1.14
VALVE ACTION / CLOSING −10 0.41 1.14
Valve C
VALVE ACTION / OPENING 2 4.4 5.49
VALVE ACTION / CLOSING −2 NR NR
VALVE ACTION / OPENING 5 5.58 7.06
VALVE ACTION / CLOSING −5 2.16 3.9
VALVE ACTION / OPENING 10 0.69 1.63
VALVE ACTION / CLOSING −10 0.53 1.25
NR = No Response
Figure 2-4. Valve Response Time Summary
Typically, these characteristics areplotted on a curve where the horizon-tal axis is labeled in percent travel al-though the vertical axis is labeled aspercent flow (or Cv). Since valve flowis a function of both the valve traveland the pressure drop across thevalve, it is traditional to conduct inher-ent valve characteristic tests at aconstant pressure drop. This is not anormal situation in practice, but it pro-vides a systematic way of comparingone valve characteristic design toanother.
Under the specific conditions ofconstant pressure drop, the valve flowbecomes only a function of the valvetravel and the inherent design of thevalve trim. These characteristics arecalled the inherent flow characteristicof the valve. Typical valve characteris-
tics conducted in this manner arenamed linear, equal percentage, andquick opening. (See ConventionalCharacterized Valve Plugs in Chapter3 for a complete description.)
The ratio of the incremental change invalve flow (output) to the correspond-ing increment of valve travel (input)which caused the flow change is de-fined as the valve gain; that is,
Inherent Valve Gain = (change inflow)/(change in travel) = slope of theinherent characteristic curve
The linear characteristic has aconstant inherent valve gain through-out its range, and the quick-openingcharacteristic has an inherent valvegain that is the greatest at the lowerend of the travel range. The greatestinherent valve gain for the equal per-
Chapter 2. Control Valve Performance
33
Figure 2-5. Installed Flow Characteristic and Gain
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centage valve is at the largest valveopening.
Inherent valve characteristic is an in-herent function of the valve flow pas-sage geometry and does not changeas long as the pressure drop is heldconstant. Many valve designs, particu-larly rotary ball valves, butterflyvalves, and eccentric plug valves,have inherent characteristics, whichcannot be easily changed; however,most globe valves have a selection ofvalve cages or plugs that can be inter-changed to modify the inherent flowcharacteristic.
Knowledge of the inherent valve char-acteristic is useful, but the more im-portant characteristic for purposes ofprocess optimization is the installedflow characteristic of the entire pro-cess, including the valve and all otherequipment in the loop. The installedflow characteristic is defined as therelationship between the flow throughthe valve and the valve assembly in-put when the valve is installed in aspecific system, and the pressuredrop across the valve is allowed tochange naturally, rather than beingheld constant. An illustration of suchan installed flow characteristic isshown in the upper curve of figure
2-5. The flow in this figure is related tothe more familiar valve travel ratherthan valve assembly input.
Installed gain, shown in the lowercurve of figure 2-5, is a plot of theslope of the upper curve at each point.Installed flow characteristic curvessuch as this can be obtained underlaboratory conditions by placing theentire loop in operation at some nomi-nal set point and with no load distur-bances. The loop is placed in manualoperation, and the flow is then mea-sured and recorded as the input to thecontrol valve assembly is manuallydriven through its full travel range. Aplot of the results is the installed flowcharacteristic curve shown in the up-per part of figure 2-5. The slope of thisflow curve is then evaluated at eachpoint on the curve and plotted as theinstalled gain as shown in the lowerpart of figure 2-5.
Field measurements of the installedprocess gain can also be made at asingle operating point using open-loopstep tests (figure 2-3). The installedprocess gain at any operating condi-tion is simply the ratio of the percentchange in output (flow) to the percentchange in valve assembly input sig-nal.
Chapter 2. Control Valve Performance
34
The reason for characterizing inherentvalve gain through various valve trimdesigns is to provide compensationfor other gain changes in the controlloop. The end goal is to maintain aloop gain, which is reasonably uniformover the entire operating range, tomaintain a relatively linear installedflow characteristic for the process(see definition in Chapter 1). Becauseof the way it is measured, as definedabove, the installed flow characteristicand installed gain represented in fig-ure 2-5 are really the installed gainand flow characteristic for the entireprocess.
Typically, the gain of the unit beingcontrolled changes with flow. For ex-ample, the gain of a pressure vesseltends to decrease with throughput. Inthis case, the process control engi-neer would then likely want to use anequal percentage valve that has anincreasing gain with flow. Ideally,these two inverse relationships shouldbalance out to provide a more linearinstalled flow characteristic for the en-tire process.
Theoretically, a loop has been tunedfor optimum performance at some setpoint flow condition. As the flow variesabout that set point, it is desirable tokeep the loop gain as constant aspossible to maintain optimum perfor-mance. If the loop gain change due tothe inherent valve characteristic doesnot exactly compensate for the chang-ing gain of the unit being controlled,then there will be a variation in theloop gain due to variation in theinstalled process gain. As a result,process optimization becomes moredifficult. There is also a danger thatthe loop gain might change enough tocause instability, limit cycling, or otherdynamic difficulties.
Loop gain should not vary more thana 4-to-1 ratio; otherwise, the dynamicperformance of the loop suffers unac-ceptably. There is nothing magicabout this specific ratio; it is simplyone which many control practitioners
agree produces an acceptable rangeof gain margins in most process con-trol loops.
This guideline forms the basis for thefollowing EnTech gain limit specifica-tion (From Control Valve DynamicSpecification, Version 3.0, November1998, EnTech Control Inc., Toronto,Ontario, Canada):
Loop Process Gain = 1.0 (% oftransmitter span)/(% controller out-put)
Nominal Range: 0.5 - 2.0 (Note4-to-1 ratio)
Note that this definition of the loopprocess includes all the devices in theloop configuration except the control-ler. In other words, the product of thegains of such devices as the controlvalve assembly, the heat exchanger,pressure vessel, or other system be-ing controlled, the pump, the transmit-ter, etc. is the process gain. Becausethe valve is part of the loop processas defined here, it is important to se-lect a valve style and size that will pro-duce an installed flow characteristicthat is sufficiently linear to stay withinthe specified gain limits over the oper-ating range of the system. If too muchgain variation occurs in the controlvalve itself, it leaves less flexibility inadjusting the controller. It is goodpractice to keep as much of the loopgain in the controller as possible.
Although the 4-to-1 ratio of gainchange in the loop is widely accepted,not everyone agrees with the 0.5 to2.0 gain limits. Some industry expertshave made a case for using loop pro-cess gain limits from 0.2 to 0.8, whichis still a 4-to-1 ratio. The potential dan-ger inherent in using this reduced gainrange is that the low end of the gainrange could result in large valveswings during normal operation. It isgood operating practice to keep valveswings below about 5%. However,there is also a danger in letting thegain get too large. The loop can be-come oscillatory or even unstable ifthe loop gain gets too high at some
Chapter 2. Control Valve Performance
35
Figure 2-6. Effect of Valve Style on Control Range
A7156 / IL
point in the travel. To ensure good dy-namic performance and loop stabilityover a wide range of operating condi-tions, industry experts recommendthat loop equipment be engineered sothe process gain remains within therange of 0.5 to 2.0.
Process optimization requires a valvestyle and size be chosen that will keepthe process gain within the selectedgain limit range over the widest pos-sible set of operating conditions. Be-cause minimizing process variability isso dependent on maintaining a uni-form installed gain, the range overwhich a valve can operate within theacceptable gain specification limits isknown as the control range of thevalve.
The control range of a valve variesdramatically with valve style. Figure2-6 shows a line-size butterfly valvecompared to a line-size globe valve.The globe valve has a much widercontrol range than the butterfly valve.Other valve styles, such as V-notchball valves and eccentric plug valvesgenerally fall somewhere betweenthese two ranges.
Because butterfly valves typicallyhave the narrowest control range,they are generally best suited forfixed-load applications. In addition,they must be carefully sized for opti-mal performance at fixed loads.
If the inherent characteristic of a valvecould be selected to exactly compen-sate for the system gain change withflow, one would expect the installedprocess gain (lower curve) to be es-sentially a straight line at a value of1.0.
Unfortunately, such a precise gainmatch is seldom possible due to thelogistical limitations of providing an in-finite variety of inherent valve trimcharacteristics. In addition, somevalve styles, such as butterfly and ballvalves, do not offer trim alternativesthat allow easy change of the inherentvalve characteristic.
This condition can be alleviated bychanging the inherent characteristicsof the valve assembly with nonlinearcams in the feedback mechanism ofthe positioner. The nonlinear feedbackcam changes the relationship be-tween the valve input signal and thevalve stem position to achieve a de-sired inherent valve characteristic for
Chapter 2. Control Valve Performance
36
the entire valve assembly, rather thansimply relying upon a change in thedesign of the valve trim.
Although the use of positioner camsdoes affect modifying the valve char-acteristic and can sometimes be use-ful, the effect of using characterizedcams is limited in most cases. This isbecause the cam also dramaticallychanges the positioner loop gain,which severely limits the dynamic re-sponse of the positioner. Using camsto characterize the valve is usually notas effective as characterizing thevalve trim, but it is always better thanno characterization at all, which isoften the only other choice with rotaryvalves.
Some electronic devices attempt toproduce valve characterization byelectronically shaping the I/P position-er input signal ahead of the positionerloop. This technique recalibrates thevalve input signal by taking the linear4-20 mA controller signal and using apre-programmed table of values toproduce the valve input required toachieve the desired valve characteris-tic. This technique is sometimes re-ferred to as forward path or set pointcharacterization.
Because this characterization occursoutside the positioner feedback loop,this type of forward path or set pointcharacterization has an advantageover characterized positioner cams. Itavoids the problem of changes in thepositioner loop gain. This method,however, also has its dynamic limita-tions. For example, there can beplaces in a valve range where a 1.0%process signal change might be nar-rowed through this characterizationprocess to only a 0.1% signal changeto the valve (that is, in the flat regionsof the characterizing curve). Manycontrol valves are unable to respondto signal changes this small.
The best process performance occurswhen the required flow characteristicis obtained through changes in thevalve trim rather than through use of
cams or other methods. Proper selec-tion of a control valve designed to pro-duce a reasonably linear installed flowcharacteristic over the operatingrange of the system is a critical step inensuring optimum process perfor-mance.
Valve SizingOversizing of valves sometimes oc-curs when trying to optimize processperformance through a reduction ofprocess variability. This results fromusing line-size valves, especially withhigh-capacity rotary valves, as well asthe conservative addition of multiplesafety factors at different stages in theprocess design.
Oversizing the valve hurts processvariability in two ways. First, the over-sized valve puts too much gain in thevalve, leaving less flexibility in adjust-ing the controller. Best performanceresults when most loop gain comesfrom the controller.
Notice in the gain curve of figure 2-5,the process gain gets quite high in theregion below about 25% valve travel.If the valve is oversized, making itmore likely to operate in or near thisregion, this high gain can likely meanthat the controller gain will need to bereduced to avoid instability problemswith the loop. This, of course, willmean a penalty of increased processvariability.
The second way oversized valves hurtprocess variability is that an oversizedvalve is likely to operate more fre-quently at lower valve openings whereseal friction can be greater, particular-ly in rotary valves. Because an over-sized valve produces a disproportion-ately large flow change for a givenincrement of valve travel, this phe-nomenon can greatly exaggerate theprocess variability associated withdead band due to friction.
Regardless of its actual inherent valvecharacteristic, a severely oversizedvalve tends to act more like a quick-
Chapter 2. Control Valve Performance
37
opening valve, which results in highinstalled process gain in the lower liftregions (figure 2-5). In addition, whenthe valve is oversized, the valve tendsto reach system capacity at relativelylow travel, making the flow curve flat-ten out at higher valve travels (figure2-5). For valve travels above about 50degrees, this valve has become totallyineffective for control purposes be-cause the process gain is approach-ing zero and the valve must undergowide changes in travel with very littleresulting changes in flow. Conse-quently, there is little hope of achiev-ing acceptable process variability inthis region.
The valve shown in figure 2-5 is totallymisapplied in this application becauseit has such a narrow control range(approximately 25 degrees to 45 de-grees). This situation came about be-cause a line-sized butterfly valve waschosen, primarily due to its low cost,and no consideration was given to thelost profit that results from sacrificingprocess variability through poor dy-namic performance of the controlvalve.
Unfortunately, this situation is oftenrepeated. Process control studiesshow that, for some industries, themajority of valves currently in processcontrol loops are oversized for the ap-plication. While it might seem counter-intuitive, it often makes economicsense to select a control valve forpresent conditions and then replacethe valve when conditions change.
When selecting a valve, it is importantto consider the valve style, inherentcharacteristic, and valve size that willprovide the broadest possible controlrange for the application.
Economic ResultsConsideration of the factors discussedin this chapter can have a dramaticimpact on the economic results of anoperating plant. More and more con-trol valve users focus on dynamic per-
formance parameters such as deadband, response times, and installedgain (under actual process load condi-tions) as a means to improveprocess-loop performance. Although itis possible to measure many of thesedynamic performance parameters inan open-loop situation, the impactthese parameters have becomes clearwhen closed-loop performance ismeasured. The closed-loop test re-sults shown in figure 2-7 demonstratethe ability of three different valves toreduce process variability over differ-ent tuning conditions.
This diagram plots process variabilityas a percent of the set point variableversus the closed-loop time constant,which is a measure of loop tuning.The horizontal line labeled Manual,shows how much variability is inherentin the loop when no attempt is madeto control it (open-loop). The line slop-ing downward to the left marked Mini-mum Variability represents the calcu-lated dynamic performance of an idealvalve assembly (one with no non-lin-earities). All real valve assembliesshould normally fall somewhere be-tween these two conditions.
Not all valves provide the same dy-namic performance even though theyall theoretically meet static perfor-mance purchase specifications andare considered to be equivalentvalves (figure 2-7). Valve A in figure2-7 does a good job of following thetrend of the minimum variability lineover a wide range of controller tun-ings. This valve shows excellent dy-namic performance with minimumvariability. In contrast, Valves B and Cdesigns fare less well and increase invariability as the system is tuned moreaggressively for decreasingclosed-loop time constants.
All three valve designs are capable ofcontrolling the process and reducingthe variability, but two designs do itless well. Consider what would hap-pen if the poorer performing Valve Bwas replaced with the best performingValve A, and the system was tuned to
Chapter 2. Control Valve Performance
38
Figure 2-7. Closed-Loop Performance
A7157 / IL
a 2.0 second closed-loop timeconstant.
The test data shows this would resultin a 1.4% improvement in processvariability. This might not seem likemuch, but the results over a time canbe impressive. A valve that can pro-vide this much improvement everyminute of every day can save signifi-cant dollars over a single year.
By maintaining closer adherence tothe set point, it is possible to achievea reduction in raw materials by mov-ing the set point closer to the lowerspecification limit. This 1.4% improve-ment in this example converts to araw material savings of 12,096 U.S.gallons per day. Assuming a materialcost of U.S. $0.25 per gallon, the bestvalve would contribute an additionalU.S. $3,024 per day directly to profits.This adds up to an impressive U.S.$1,103,760 per year.
The excellent performance of the bet-ter valve in this example providesstrong evidence that a superior controlvalve assembly can have a profoundeconomic impact. This example is
only one way a control valve can in-crease profits through tighter control.Decreased energy costs, increasedthroughput, less reprocessing cost forout-of-spec product, and so on are allways a good control valve can in-crease economic results through tight-er control. While the initial cost mightbe higher for the best control valve,the few extra dollars spent on awell-engineered control valve candramatically increase the return oninvestment. Often the extra initial costof the valve can be paid for in a matterof days.
As a result of studies such as these,the process industries have becomeincreasingly aware that control valveassemblies play an important role inloop/unit/plant performance. Theyhave also realized that traditionalmethods of specifying a valve assem-bly are no longer adequate to ensurethe benefits of process optimization.While important, such static perfor-mance indicators as flow capacity,leakage, materials compatibility, andbench performance data are not suffi-ciently adequate to deal with the dy-
Chapter 2. Control Valve Performance
39
namic characteristics of process con-trol loops.
SummaryThe control valve assembly plays anextremely important role in producingthe best possible performance fromthe control loop. Process optimizationmeans optimizing the entire process,not just the control algorithms used inthe control room equipment. Thevalve is called the final control ele-ment because the control valve as-sembly is where process control is im-plemented. It makes no sense toinstall an elaborate process controlstrategy and hardware instrumenta-tion system capable of achieving 0.5%or better process control and then toimplement that control strategy with a5% or worse control valve. Audits per-formed on thousands of process con-trol loops have provided strong proofthat the final control element plays asignificant role in achieving true pro-cess optimization. Profitability in-
creases when a control valve hasbeen properly engineered for its ap-plication.
Control valves are sophisticated,high-tech products and should not betreated as a commodity. Althoughtraditional valve specifications play animportant role, valve specificationsmust also address real dynamic per-formance characteristics if true pro-cess optimization is to be achieved. Itis imperative that these specificationsinclude such parameters as deadband, dead time, response time, etc.
Finally, process optimization beginsand ends with optimization of the en-tire loop. Parts of the loop cannot betreated individually to achieve coordi-nated loop performance. Likewise,performance of any part of the loopcannot be evaluated in isolation. Iso-lated tests under non-loaded,bench-type conditions will not provideperformance information that is ob-tained from testing the hardware un-der actual process conditions.
Chapter 2. Control Valve Performance
40
41
Chapter 3
Valve and Actuator Types
Control ValvesThe control valve regulates the rate offluid flow as the position of the valveplug or disk is changed by force fromthe actuator. To do this, the valvemust:
� Contain the fluid without externalleakage;
� Have adequate capacity for theintended service;
� Be capable of withstanding theerosive, corrosive, and temperatureinfluences of the process; and
� Incorporate appropriate end con-nections to mate with adjacent pipe-lines and actuator attachment meansto permit transmission of actuatorthrust to the valve plug stem or rotaryshaft.
Many styles of control valve bodieshave been developed through theyears. Some have found wide applica-tion; others meet specific service con-ditions and are used less frequently.The following summary describessome popular control valve bodystyles in use today.
Globe Valves
Single-Port Valve Bodies
� Single port is the most commonvalve body style and is simple inconstruction.
� Single-port valves are availablein various forms, such as globe,angle, bar stock, forged, and splitconstructions.
� Generally single-port valves arespecified for applications with strin-gent shutoff requirements. They usemetal-to-metal seating surfaces or
Chapter 3. Valve and Actuator Types
42
Figure 3-1. Single-Ported Globe-StyleValve Body
W7027-1/IL
soft-seating with PTFE or other com-position materials forming the seal.Single-port valves can handle mostservice requirements.
� Because high-pressure fluid isnormally loading the entire area of theport, the unbalance force createdmust be considered in selecting ac-tuators for single-port control valvebodies.
� Although most popular in thesmaller sizes, single-port valves canoften be used in 4-inch to 8-inch sizeswith high-thrust actuators.
� Many modern single-seatedvalve bodies use cage or retainer-style construction to retain the seat-ring cage, provide valve-plug guiding,and provide a means for establishingparticular valve flow characteristics.Retainer-style trim also offers ease ofmaintenance with flow characteristicsaltered by changing the plug.
� Cage or retainer-style single-seated valve bodies can also be easi-ly modified by change of trim parts toprovide reduced-capacity flow, noiseattenuation, or reduction or eliminationof cavitation.
Figure 3-1 shows two of the morepopular styles of single-ported orsingle-seated globe-type control valvebodies. They are widely used in pro-cess control applications, particularlyin sizes from 1-inch through 4-inch.
Figure 3-2. Flanged Angle-StyleControl Valve Body
W0971/IL
Normal flow direction is most often upthrough the seat ring.
Angle valves are nearly always singleported (figure 3-2). They are common-ly used in boiler feedwater and heaterdrain service and in piping schemeswhere space is at a premium and thevalve can also serve as an elbow. Thevalve shown has cage-style construc-tion. Others might have screwed-inseat rings, expanded outlet connec-tions, restricted trim, and outlet linersfor reduction of erosion damage.
Bar-stock valve bodies are often spe-cified for corrosive applications in thechemical industry (figure 3-3). Theycan be machined from any metallicbar-stock material and from someplastics. When exotic metal alloys arerequired for corrosion resistance, abar-stock valve body is normally lessexpensive than a valve body pro-duced from a casting.
High-pressure single-ported globevalves are often used in production ofgas and oil (figure 3-4). Variationsavailable include cage-guided trim,bolted body-to-bonnet connection,and self-draining angle versions.
Chapter 3. Valve and Actuator Types
43
Figure 3-3. Bar Stock Valve Bodies
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Figure 3-4. High Pressure Globe-StyleControl Valve Body
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Flanged versions are available withratings to Class 2500.
Balanced-Plug Cage-Style ValveBodies
This popular valve body style, single-ported in the sense that only one seatring is used, provides the advantagesof a balanced valve plug often associ-ated only with double-ported valvebodies (figure 3-5). Cage-style trimprovides valve plug guiding, seat ringretention, and flow characterization. In
Figure 3-5. Valve Body with Cage-Style Trim, Balanced Valve Plug,
and Soft Seat
W0992/IL
addition a sliding piston ring-type sealbetween the upper portion of the valveplug and the wall of the cage cylindervirtually eliminates leakage of the up-stream high pressure fluid into thelower pressure downstream system.Downstream pressure acts on boththe top and bottom sides of the valveplug, thereby nullifying most of thestatic unbalance force. Reduced un-balance permits operation of the valvewith smaller actuators than those nec-essary for conventional single-portedvalve bodies. Interchangeability of trimpermits choice of several flow charac-teristics or of noise attenuation or anti-cavitation components. For mostavailable trim designs, the standarddirection of flow is in through the cageopenings and down through the seatring. These are available in variousmaterial combinations, sizes through20-inch, and pressure ratings to Class2500.
High Capacity, Cage-Guided ValveBodies
This adaptation of the cage-guidedbodies mentioned above was de-signed for noise applications such ashigh pressure gas reducing stations
Chapter 3. Valve and Actuator Types
44
Figure 3-6. High Capacity Valve Bodywith Cage-Style Noise Abatement
Trim
W0997/IL
where sonic gas velocities are oftenencountered at the outlet of conven-tional valve bodies (figure 3-6). Thedesign incorporates oversize end con-nections with a streamlined flow pathand the ease of trim maintenance in-herent with cage-style constructions.Use of noise abatement trim reducesoverall noise levels by as much as 35decibels. Also available in cagelessversions with bolted seat ring, endconnection sizes through 20-inch,Class 600, and versions for liquid ser-vice. Flow direction depends on theintended service and trim selection,with unbalanced constructions nor-mally flowing up and balancedconstructions normally flowing down.
Port-Guided Single-Port ValveBodies
� These bodies are usually limitedto 150 psi (10 bar) maximum pressuredrop.
� They are susceptible to velocity-induced vibration.
� Port-guided single-port valvebodies are typically provided withscrewed in seat rings which might bedifficult to remove after use.
Figure 3-7. Reverse-Acting Double-Ported Globe-Style Valve Body
W0467/IL
Double-Ported Valve Bodies
� Dynamic force on plug tends tobe balanced as flow tends to openone port and close the other.
� Reduced dynamic forces actingon plug might permit choosing asmaller actuator than would be neces-sary for a single-ported valve bodywith similar capacity.
� Bodies are usually furnishedonly in the larger sizes—4-inch orlarger.
� Bodies normally have higher ca-pacity than single-ported valves of thesame line size.
� Many double-ported bodies re-verse, so the valve plug can beinstalled as either push-down-to-openor push-down-to-close (figure 3-7).
� Metal-to-metal seating usuallyprovides only Class II shutoff capabili-ty, although Class III capability is alsopossible.
� Port-guided valve plugs areoften used for on-off or low-pressurethrottling service. Top-and-bottom-guided valve plugs furnish stable op-eration for severe service conditions.
Chapter 3. Valve and Actuator Types
45
The control valve body shown in fig-ure 3-7 is assembled for push-down-to-open valve plug action. The valveplug is essentially balanced and a rel-atively small amount of actuator forceis required to operate the valve.Double ported designs are typicallyused in refineries on highly viscousfluids or where there is a concernabout dirt, contaminants, or processdeposits on the trim.
Three-Way Valve Bodies
� Three pipeline connections pro-vide general converging (flow-mixing)or diverging (flow-splitting) service.
� Best designs use cage-style trimfor positive valve plug guiding andease of maintenance.
� Variations include trim materialsselected for high temperature service.Standard end connections (flanged,screwed, butt weld, etc.) can be speci-fied to mate with most any pipingscheme.
� Actuator selection demandscareful consideration, particularly forconstructions with unbalanced valveplug.
Balanced valve plug style three-wayvalve body is shown with cylindricalvalve plug in the down position (figure3-8). This position opens the bottomcommon port to the right-hand portand shuts off the left-hand port. Theconstruction can be used for throttlingmid-travel position control of eitherconverging or diverging fluids.
Rotary Valves
Butterfly Valve Bodies
� Bodies require minimum spacefor installation (figure 3-9).
� They provide high capacity withlow pressure loss through the valves.
Figure 3-8. Three Way Valvewith Balanced Valve Plug
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Figure 3-9. High-PerformanceButterfly Control Valve
W4641
� Butterfly valve bodies offer econ-omy, particularly in larger sizes and interms of flow capacity per investmentdollar.
� Conventional contoured disksprovide throttling control for up to60-degree disk rotation. Patented, dy-namically streamlined disks suit ap-plications requiring 90-degree diskrotation.
� Bodies mate with standardraised-face pipeline flanges.
� Butterfly valve bodies might re-quire high-output or large actuators if
Chapter 3. Valve and Actuator Types
46
Figure 3-10. Rotary-Shaft ControlValve with V-Notch Ball
W8172-2
the valve is big or the pressure drop ishigh, because operating torques mightbe quite large.
� Units are available for service innuclear power plant applications withvery stringent leakage requirements.
� Standard liner can provide goodshutoff and corrosion protection withnitrile or PTFE liner.
� Standard butterfly valves areavailable in sizes through 72-inch formiscellaneous control valve applica-tions. Smaller sizes can use versionsof traditional diaphragm or pistonpneumatic actuators, including themodern rotary actuator styles. Largersizes might require high-output elec-tric or long-stroke pneumatic cylinderactuators. Butterfly valves exhibit anapproximately equal percentage flowcharacteristic. They can be used forthrottling service or for on-off control.Soft-seat construction can be ob-tained by using a liner or by includingan adjustable soft ring in the body oron the face of the disk.
V-Notch Ball Control Valve Bodies
This construction is similar to a con-ventional ball valve, but with patented,contoured V-notch in the ball (figure3-10). The V-notch produces anequal-percentage flow characteristic.
These control valves have goodrangeability, control, and shutoff capa-bility. The paper industry, chemicalplants, sewage treatment plants, thepower industry, and petroleum refiner-ies use such valve bodies.
� Straight-through flow design pro-duces little pressure drop.
� V-notch ball control valve bodiesare suited to control of erosive or vis-cous fluids, paper stock, or other slur-ries containing entrained solids or fi-bers.
� They use standard diaphragm orpiston rotary actuators.
� Ball remains in contact with sealduring rotation, which produces ashearing effect as the ball closes andminimizes clogging.
� Bodies are available with eitherheavy-duty or PTFE-filled compositionball seal ring to provide excellentrangeability in excess of 300:1.
� V-notch ball control valve bodiesare available in flangeless or flanged-body end connections. Both flangedand flangeless valves mate with Class150, 300, or 600 flanges or DINflanges.
Eccentric-Disk Control ValveBodies
� Bodies offer effective throttlingcontrol.
� Eccentric-disk control valve bod-ies provide linear flow characteristicthrough 90 degrees of disk rotation(figure 3-11).
� Eccentric mounting of disk pullsit away from seal after it begins toopen, minimizing seal wear.
� Eccentric-disk control valve bod-ies are available in sizes through24-inch compatible with standardASME flanges.
Chapter 3. Valve and Actuator Types
47
Figure 3-11. Eccentric-DiskRotary-Shaft Control Valve
W8380
� They use standard pneumaticdiaphragm or piston rotary actuators.
� Standard flow direction is depen-dent on seal design; reverse flow re-sults in reduced capacity.
Eccentric disk rotary shaft controlvalves are intended for general ser-vice applications not requiring preci-sion throttling control. They are fre-quently applied in applicationsrequiring large sizes and high temper-atures due to their lower cost relativeto other styles of control valves. Thecontrol range for this style of valve isapproximately one third as large as aball or globe style valves. Conse-quently, additional care is required insizing and applying this style of valveto eliminate control problems associ-ated with process load changes. Theywork quite well for constant processload applications.
Eccentric-Plug Control ValveBodies
� Valve assembly combats ero-sion. The rugged body and trim de-sign handle temperatures to 800�F(427�C) and shutoff pressure drops to1500 psi (103 bar).
Figure 3-12. Sectional of Eccentric-Plug Control Valve Body
W4170/IL
� Path of eccentric plug minimizescontact with the seat ring when open-ing, reducing seat wear and friction,prolonging seat life, and improvingthrottling performance (figure 3-12)..
� Self-centering seat ring andrugged plug allow forward or reverseflow with tight shutoff in either direc-tion. Plug, seat ring and retainer areavailable in hardened materials, in-cluding ceramics, for selection of ero-sion resistance.
� Designs offering a segmentedV-notch ball in place of the plug forhigher capacity requirements areavailable.
This style of rotary control valve suitserosive, coking and other hard-to-han-dle fluids, providing either throttling oron-off operation. The flanged orflangeless valves feature streamlinedflow passages and rugged metal-trimcomponents for dependable service inslurry applications. Mining, petroleumrefining, power, and pulp and paperindustries use these valves.
Control Valve EndConnectionsThe three common methods of instal-ling control valves in pipelines are bymeans of screwed pipe threads,bolted gasketed flanges, and weldedend connections.
Screwed Pipe ThreadsScrewed end connections, popular insmall control valves, offer more econ-
Chapter 3. Valve and Actuator Types
48
Figure 3-13. Popular Varieties ofBolted Flange Connections
A7098/IL
omy than flanged ends. The threadsusually specified are tapered femaleNPT (National Pipe Thread) on thevalve body. They form a metal-to-met-al seal by wedging over the matingmale threads on the pipeline ends.This connection style, usually limitedto valves not larger than 2-inch, is notrecommended for elevated tempera-ture service. Valve maintenance mightbe complicated by screwed end con-nections if it is necessary to take thebody out of the pipeline because thevalve cannot be removed withoutbreaking a flanged joint or union con-nection to permit unscrewing the valvebody from the pipeline.
Bolted Gasketed FlangesFlanged end valves are easily re-moved from the piping and are suit-able for use through the range ofworking pressures for which mostcontrol valves are manufactured (fig-ure 3-13). Flanged end connectionscan be used in a temperature rangefrom absolute zero to approximately1500�F (815�C). They are used on allvalve sizes. The most commonflanged end connections include flatface, raised face, and ring type joint.
The flat face variety allows the match-ing flanges to be in full face contactwith the gasket clamped betweenthem. This construction is commonlyused in low pressure, cast iron andbrass valves and minimizes flangestresses caused by initial bolting-upforce.
The raised face flange features a cir-cular raised face with inside diameterthe same as the valve opening andwith the outside diameter somethingless than the bolt circle diameter. Theraised face is finished with concentriccircular grooves for good sealing andresistance to gasket blowout. Thiskind of flange is used with a variety ofgasket materials and flange materialsfor pressures through the 6000 psig(414 bar) pressure range and for tem-peratures through 1500�F (815�C).This style of flanging is normally stan-dard on Class 250 cast iron bodiesand all steel and alloy steel bodies.
The ring-type joint flange looks likethe raised-face flange except that aU-shaped groove is cut in the raisedface concentric with the valve open-ing. The gasket consists of a metalring with either an elliptical or octago-nal cross section. When the flangebolts are tightened, the gasket iswedged into the groove of the matingflange and a tight seal is made. Thegasket is generally soft iron or Monel(Trademark of Inco Alloys Internation-al) but is available in almost any met-al. This makes an excellent joint athigh pressure and is used up to15,000 psig (1034 bar), but is general-ly not used at high temperatures. It isfurnished only on steel and alloy valvebodies when specified.
Welding End ConnectionsWelding ends on control valves areleak tight at all pressures and temper-atures and are economical in first cost(figure 3-14). Welding end valves aremore difficult to take from the line andare obviously limited to weldable ma-terials. Welding ends come in two
Chapter 3. Valve and Actuator Types
49
Figure 3-14. Common Welded EndConnections
A7099/IL
styles, socket welding and buttweld-ing.
The socket welding ends are preparedby boring in each end of the valve asocket with an inside diameter slightlylarger than the pipe outside diameter.The pipe slips into the socket where itbutts against a shoulder and thenjoins to the valve with a fillet weld.Socket welding ends in a given sizeare dimensionally the same regard-less of pipe schedule. They are usual-ly furnished in sizes through 2-inch.
The buttwelding ends are prepared bybeveling each end of the valve tomatch a similar bevel on the pipe. Thetwo ends are then butted to the pipe-line and joined with a full penetrationweld. This type of joint is used on allvalve styles and the end preparationmust be different for each schedule ofpipe. These are generally furnishedfor control valves in sizes 2-1/2-inchand larger. Care must be exercisedwhen welding valve bodies in thepipeline to prevent excessive heattransmitted to valve trim parts. Trimswith low-temperature composition ma-terials must be removed before weld-ing.
Figure 3-15. Typical Bonnet,Flange, and Stud Bolts
W0989/IL
Valve Body BonnetsThe bonnet of a control valve is thatpart of the body assembly throughwhich the valve plug stem or rotaryshaft moves. On globe or angle bod-ies, it is the pressure retaining compo-nent for one end of the valve body.The bonnet normally provides ameans of mounting the actuator to thebody and houses the packing box.Generally rotary valves do not havebonnets. (On some rotary-shaftvalves, the packing is housed withinan extension of the valve body itself,or the packing box is a separate com-ponent bolted between the valve bodyand bonnet.)
On a typical globe-style control valvebody, the bonnet is made of the samematerial as the valve body or is anequivalent forged material because itis a pressure-containing member sub-ject to the same temperature and cor-rosion effects as the body. Severalstyles of valve body-to-bonnet con-nections are illustrated. The mostcommon is the bolted flange typeshown in figure 3-15 showing a bon-net with an integral flange and figure3-3 showing a bonnet with a separa-ble, slip-on flange held in place with a
Chapter 3. Valve and Actuator Types
50
split ring. The bonnet used on the highpressure globe valve body in figure3-4 is screwed into the valve body.Figure 3-9 is typical of rotary-shaftcontrol valves where the packing ishoused within the valve body and abonnet is not used. The actuator link-age housing is not a pressure-contain-ing part and is intended to enclose thelinkage for safety and environmentalprotection.
On control valve bodies with cage- orretainer-style trim, the bonnet fur-nishes loading force to prevent leak-age between the bonnet flange andthe valve body and also between theseat ring and the valve body. Thetightening of the body-bonnet boltingcompresses a flat sheet gasket to sealthe body-bonnet joint, compresses aspiral-wound gasket on top of thecage, and compresses another flatsheet gasket below the seat ring toprovide the seat ring-body seal. Thebonnet also provides alignment for thecage, which in turn guides the valveplug, to ensure proper valve plug stemalignment with the packing.
As mentioned, the conventional bon-net on a globe-type control valvehouses the packing. The packing ismost often retained by a packing fol-lower held in place by a flange on theyoke boss area of the bonnet (figure3-15). An alternate packing retentionmeans is where the packing followeris held in place by a screwed gland(figure 3-3). This alternate is compact,so it is often used on small controlvalves; however, the user cannot al-ways be sure of thread engagement.Therefore, caution should be used inadjusting packing compression whenthe control valve is in service.
Most bolted-flange bonnets have anarea on the side of the packing boxwhich can be drilled and tapped. Thisopening is closed with a standard pipeplug unless one of the following condi-tions exists:
Figure 3-16. Extension Bonnet
W0667/IL
� It is necessary to purge thevalve body and bonnet of processfluid, in which case the opening canbe used as a purge connection.
� The bonnet opening is beingused to detect leakage from the firstset of packing or from a failed bellowsseal.
Extension BonnetsExtension bonnets are used for eitherhigh or low temperature service toprotect valve stem packing from ex-treme process temperatures. Stan-dard PTFE valve stem packing is use-ful for most applications up to 450�F(232�C). However, it is susceptible todamage at low process temperaturesif frost forms on the valve stem. Thefrost crystals can cut grooves in thePTFE, forming leakage paths for pro-cess fluid along the stem. Extensionbonnets remove the packing box ofthe bonnet far enough from the ex-treme temperature of the process thatthe packing temperature remains with-in the recommended range.
Extension bonnets are either cast (fig-ure 3-16) or fabricated (figure 3-17).Cast extensions offer better high-tem-perature service because of greaterheat emissivity, which provides bettercooling effect. Conversely, smooth
Chapter 3. Valve and Actuator Types
51
Figure 3-17. Valve Body with Fabricated Extension Bonnet
W1416IL
surfaces, such as can be fabricatedfrom stainless steel tubing, are pre-ferred for cold service because heatinflux is normally the major concern.In either case, extension wall thick-ness should be minimized to cut downheat transfer. Stainless steel is usuallypreferable to carbon steel because ofits lower coefficient of thermal conduc-tivity. On cold service applications, in-sulation can be added around the ex-tension to protect further against heatinflux.
Bellows Seal BonnetsBellows seal bonnets (figure 3-18) areused when no leakage (less than1x10-6 cc/sec of helium) along thestem can be tolerated. They are oftenused when the process fluid is toxic,volatile, radioactive, or highly expen-sive. This special bonnet constructionprotects both the stem and the valvepacking from contact with the processfluid. Standard or environmental pack-ing box constructions above the bel-lows seal unit will prevent catastrophicfailure in case of rupture or failure ofthe bellows.
As with other control valve pressure/temperature limitations, these pres-
Figure 3-18. ENVIRO-SEAL� BellowsSeal Bonnet
W6434
Figure 3-19. Mechanically FormedBellows
A5954/IL
sure ratings decrease with increasingtemperature. Selection of a bellowsseal design should be carefully con-sidered and particular attention shouldbe paid to proper inspection andmaintenance after installation. Thebellows material should be carefullyconsidered to ensure the maximumcycle life.
Two types of bellows seal designs areused for control valves. These aremechanically formed and welded leafbellows (figure 3-19 and figure 3-20respectively). The welded-leaf designoffers a shorter total package height.Due to its method of manufacture andinherent design, service life may be
Chapter 3. Valve and Actuator Types
52
Figure 3-21. Comprehensive Packing Material Arrangementsfor Globe-Style Valve Bodies
B2565 / IL LOCATION OF SACRIFICIAL ZINC WASHER,IF USED.
GRAPHITE PACKING ARRANGEMENTS
14A1849-E
1
12A7837-A
STANDARD
TFE V-RING
13A9775-E
Figure 3-20. Welded Leaf Bellows
A5955/IL
limited. The mechanically formed bel-lows is taller in comparison and is pro-duced with a more repeatablemanufacturing process.
Control Valve PackingMost control valves use packingboxes with the packing retained andadjusted by a flange and stud bolts(figure 3-23). Several packing materi-als can be used depending on the ser-vice conditions expected and whetherthe application requires compliance toenvironmental regulations. Brief de-scriptions and service condition guide-lines for several popular materials and
typical packing material arrangementsare shown in figure 3-21.
PTFE V-Ring� Plastic material with inherent
ability to minimize friction.
� Molded in V-shaped rings thatare spring loaded and self-adjusting inthe packing box. Packing lubricationnot required.
� Resistant to most known chemi-cals except molten alkali metals.
� Requires extremely smooth (2 to4 micro-inches RMS) stem finish toseal properly. Will leak if stem orpacking surface is damaged.
� Recommended temperature lim-its: −40 to +450�F (−40 to +232�C)
� Not suitable for nuclear servicebecause PTFE is easily destroyed byradiation.
Laminated and FilamentGraphite
� Suitable for high temperature nu-clear service or where low chloridecontent is desirable (Grade GTN).
Chapter 3. Valve and Actuator Types
53
� Provides leak-free operation,high thermal conductivity, and longservice life, but produces high stemfriction and resultant hysteresis.
� Impervious to most hard-to-han-dle fluids and high radiation.
� Suitable temperature range:Cryogenic temperatures to 1200�F(649�C)
� Lubrication not required, but anextension bonnet or steel yoke shouldbe used when packing box tempera-ture exceeds 800�F (427�C).
USA Regulatory Requirementsfor Fugitive EmissionsFugitive emissions are non-pointsource volatile organic emissionswhich result from process equipmentleaks. Equipment leaks in the UnitedStates have been estimated at over400 million pounds per year. Strictgovernment regulations, developed bythe US, dictate leak detection and re-pair programs (LDAR). Valves andpumps have been identified as keysources of fugitive emissions. Forvalves, this is the leakage to atmo-sphere due to packing seal or gasketfailures.
The LDAR programs require industryto monitor all valves (control and non-control) at an interval that is deter-mined by the percentage of valvesfound to be leaking above a thresholdlevel of 500 ppmv (some cities use a100 ppmv criteria). This leakage levelis so slight you cannot see or hear it.The use of sophisticated portablemonitoring equipment is required fordetection. Detection occurs by sniffingthe valve packing area for leakage us-ing an Environmental ProtectionAgency (EPA) protocol. This is a cost-ly and burdensome process for indus-try.
The regulations do allow for the exten-sion of the monitoring period for up toone year if the facility can demon-
strate a very low ongoing percentageof leaking valves (less than 0.5% ofthe total valve population). The oppor-tunity to extend the measurement fre-quency is shown in figure 3-22.
Packing systems designed for ex-tremely low leakage requirementsalso extend packing-seal life and per-formance to support an annual moni-toring objective. The ENVIRO-SEAL�packing system is one example. Itsenhanced seals incorporate four keydesign principles. These are the con-tainment of the pliable seal materialthrough an anti-extrusion component,proper alignment of the valve stem orshaft within the bonnet bore, applyinga constant packing stress throughbelleville springs and minimizing thenumber of seal rings to reduce consol-idation, friction, and thermal expan-sion.
The traditional valve selection processmeant choosing a valve design basedon its pressure and temperature capa-bilities, flow characteristics and mate-rial compatibility. Which valve stempacking to use in the valve was deter-mined primarily by the operating tem-perature in the packing box area. Theavailable material choices includedPTFE for temperatures below 93�C(200�F) and graphite for higher tem-perature applications.
Today, choosing a valve packing sys-tem has become much more involveddue to a number of considerations.For example, emissions control re-quirements such as those imposed bythe Clean Air Act within the UnitedStates and by other regulatory bodiesplace tighter restrictions on sealingperformance. Constant demands forimproved process output mean thatthe valve packing system must nothinder valve performance. Andtoday’s trend toward extended mainte-nance schedules dictates that valvepacking systems provide the requiredsealing over longer periods.
Given the wide variety of valve ap-plications and service conditions with-
Chapter 3. Valve and Actuator Types
54
B2566/IL
Figure 3-22. Measurement Frequency for ValvesControlling Volatile Organic Chemicals (VOC)
in industry, these variables (sealingability, operating friction levels, operat-ing life) are difficult to quantify andcompare. The tables that follow utilizean engineered approach in providinga relative evaluation of packing appli-cability and performance. But first,proper understanding of the tables re-quires a clarification of trade names.
Single PTFE V-Ring Packing (Fig. 3-23)
The single PTFE V-ring arrangementuses a coil spring between the pack-ing and packing follower. It meets the100 ppmv criteria, assuming that thepressure does not exceed 20.7 bar(300 psi) and the temperature is be-tween −18�C and 93�C (0�F and200�F). It offers very good sealingperformance with the lowest operatingfriction.
ENVIRO-SEAL� PTFE Packing(Fig. 3-24)
The ENVIRO-SEAL PTFE packingsystem is an advanced packing meth-od that utilizes a compact, live-loadspring design suited to environmental
Figure 3-23. Single PTFEV-Ring Packing
A6161/IL
applications up to 51.7 bar and 232�C(750 psi and 450�F). While it mosttypically is thought of as an emission-reducing packing system, ENVIRO-SEAL PTFE packing is suited also tonon-environmental applications involv-
Chapter 3. Valve and Actuator Types
55
Figure 3-24. ENVIRO-SEAL PTFE Packing System
A6163/IL
ing high temperatures and pressures,yielding the benefit of longer, ongoingservice life.
ENVIRO-SEAL Duplex Packing (Fig. 3-25)
This special packing system providesthe capabilities of both PTFE andgraphite components to yield a lowfriction, low emission, fire-tested solu-tion (API Standard 589) for applica-tions with process temperatures up to232�C (450�F).
KALREZ� Packing
The KALREZ pressure/temperaturelimits referenced are for Fisher valveapplications only. KALREZ with PTFEis suited to environmental use up to24.1 bar and 204�C (350 psi and400�F) and to some non-environmen-tal services up to 103 bar (1500 psi).KALREZ with ZYMAXX, which is acarbon fiber-reinforced TFE, is suitedto 260�C (500 F) service.
ENVIRO-SEAL� Graphite ULF (Fig. 3-26)
This packing system is designed pri-marily for environmental applicationsat temperatures in excess of 232�C(450�F). The patented ULF packingsystem incorporates very thin PTFElayers inside the packing rings as wellas thing PTFE washers on each sideof the packing rings. This strategicplacement of PTFE minimizes controlproblems, reduces friction, promotessealing and extends the cycle life ofthe packing set.
HIGH-SEAL� Graphite ULF
Identical to the ENVIRO-SEAL graph-ite ULF packing system below thepacking follower, the HIGH-SEAL sys-tem utilizes heavy-duty, large diame-ter Belleville springs. These springsprovide additional follower travel andcan be calibrated with a load scale fora visual indication of packing load andwear.
Chapter 3. Valve and Actuator Types
56
Figure 3-25. ENVIRO-SEAL� Duplex (PTFE andGraphite) Packing System
24B9310A6844 / IL
PTFE-CARBON/PTFEPACKING SET
LANTERNRING
GRAPHITEPACKING RING
PACKINGBOX RING
SPRING PACKASSEMBLY
BUSHING
BUSHING
PACKINGWASHERS
BUSHING
Figure 3-26. ENVIRO-SEAL GraphiteULF Packing System
39B4612-A
Chapter 3. Valve and Actuator Types
57
Figure 3-27. ENVIRO-SEAL� GraphitePacking System for Rotary Valves
W6125-1/IL
ENVIRO-SEAL� Graphite forRotary Valves (Fig. 3-27)
ENVIRO-SEAL graphite packing isdesigned for environmental applica-tions from −6�C to 316�C (20�F to600�F) or for those applications wherefire safety is a concern. It can be usedwith pressures to 103 bar (1500 psi)and still satisfy the 500 ppmv EPAleakage criteria.
Graphite Ribbon for Rotary Valves
Graphite ribbon packing is designed
for non-environmental applicationsthat span a wide temperature rangefrom −198�C to 538�C (−325�F to1000�F).
The following table provides a com-parison of various sliding-stem pack-ing selections and a relative ranking ofseal performance, service life, andpacking friction for environmental ap-plications. Braided graphite filamentand double PTFE are not acceptableenvironmental sealing solutions.
Sliding-Stem Environmental Packing Selection
PackingSystem
Maximum Pressure &Temperature Limits for 500 PPM
Service(1)Seal
PerformanceIndex
ServiceLife
Index
PackingFriction
CustomaryUS
Metric
Single PTFEV-Ring
300 psi0 to 200�F
20.7 bar-18 to 93�C
Better Long Very Low
ENVIRO-SEALPTFE
See Fig. 3-25-50 to 450�F
See Fig. 3-25-46 to 232�C
Superior Very Long Low
ENVIRO-SEALDuplex
750 psi-50 to 450�F
51.7 bar-46 to 232�C
Superior Very Long Low
ENVIRO-SEALGraphite ULF
1500 psi20 to 600�F
103 bar-7 to 315�C
Superior Very Long Moderate
(1) The values shown are only guidelines. These guidelines can be exceeded, but shortened packing life or increasedleakage might result. The temperature ratings apply to the actual packing temperature, not to the process temperature.
Chapter 3. Valve and Actuator Types
58
Figure 3-28. Characterized Cages for Globe-Style Valve Bodies
QUICK OPENING EQUAL PERCENTAGELINEAR
W0959/ILW0958/IL W0957/IL
The following applies to rotary valves.In the case of rotary valves, singlePTFE and graphite ribbon packing ar-
rangements do not perform well as fu-gitive emission sealing solutions.
Rotary Environmental Packing Selection
PackingSystem
Maximum Pressure &Temperature Limits for 500 PPM
Service(1)Seal
PerformanceIndex
Service LifeIndex
PackingFriction
CustomaryUS
Metric
ENVIRO-SEALPTFE
1500 psig-50 to 450�F
103 bar-46 to 232�C
Superior Very Long Low
ENVIRO-SEALGraphite
1500 psig20 to 600�F
103 bar-18 to 315�C
Superior Very Long Moderate
(1) The values shown are only guidelines. These guidelines can be exceeded, but shortened packing life or increasedleakage might result. The temperature ratings apply to the actual packing temperature, not to the process temperature.
The control of valve fugitive emissionsand a reduction in industry’s cost ofregulatory compliance can beachieved through these stem sealingtechnologies.
While ENVIRO-SEAL packing sys-tems have been designed specificallyfor fugitive emission applications,these technologies also should beconsidered for any application whereseal performance and seal life havebeen an ongoing concern or mainte-nance cost issue.
Characterization ofCage-Guided ValveBodiesIn valve bodies with cage-guided trim,the shape of the flow openings or win-dows in the wall of the cylindrical cage
determines flow characterization. Asthe valve plug is moved away from theseat ring, the cage windows areopened to permit flow through thevalve. Standard cages have been de-signed to produce linear, equal-per-centage, and quick-opening inherentflow characteristics. Note the differ-ences in the shapes of the cage win-dows shown in figure 3-28. The flowrate/travel relationship provided byvalves using these cages is equivalentto the linear, quick-opening, andequal-percentage curves shown forcontoured valve plugs (figure 3-29).
Cage-guided trim in a control valveprovides a distinct advantage overconventional valve body assemblies inthat maintenance and replacement ofinternal parts is much simplified. Theinherent flow characteristic of thevalve can be easily changed by instal-
Chapter 3. Valve and Actuator Types
59
Figure 3-29. Inherent FlowCharacteristics Curves
A3449/IL
ling a different cage. Interchange ofcages to provide a different inherentflow characteristic does not requirechanging valve plug or seat ring. Thestandard cages shown can be usedwith either balanced or unbalancedtrim constructions. Soft seating, whenrequired, is available as a retained in-sert in the seat ring and is indepen-dent of cage or valve plug selection.
Cage interchangeability can be ex-tended to specialized cage designsthat provide noise attenuation or com-bat cavitation. These cages furnish amodified linear inherent flow charac-teristic, but require flow to be in a spe-cific direction through the cage open-ings. Therefore, it could be necessaryto reverse the valve body in the pipe-line to obtain proper flow direction.
Characterized Valve PlugsThe valve plug, the movable part of aglobe-style control valve assembly,provides a variable restriction to fluidflow. Valve plug styles are each de-signed to provide a specific flow char-acteristic, permit a specified mannerof guiding or alignment with the seatring, or have a particular shutoff ordamage-resistance capability.
Valve plugs are designed for eithertwo-position or throttling control. Intwo-position applications, the valve
plug is positioned by the actuator ateither of two points within the travelrange of the assembly. In throttlingcontrol, the valve plug can be posi-tioned at any point within the travelrange as dictated by the process re-quirements.
The contour of the valve plug surfacenext to the seat ring is instrumental indetermining the inherent flow charac-teristic of a conventional globe-stylecontrol valve. As the actuator movesthe valve plug through its travel range,the unobstructed flow area changes insize and shape depending on the con-tour of the valve plug. When aconstant pressure differential is main-tained across the valve, the changingrelationship between percentage ofmaximum flow capacity and percent-age of total travel range can be por-trayed (figure 3-29), and is designatedas the inherent flow characteristic ofthe valve.
Commonly specified inherent flowcharacteristics include:
Linear Flow Characteristic⎯A valvewith an ideal linear inherent flow char-acteristic produces flow rate directlyproportional to the amount of valveplug travel, throughout the travelrange. For instance, at 50% of ratedtravel, flow rate is 50% of maximumflow; at 80% of rated travel, flow rateis 80% of maximum; etc. Change offlow rate is constant with respect tovalve plug travel. Valves with a linearcharacteristic are often specified forliquid level control and for flow controlapplications requiring constant gain.
Equal-Percentage Flow Character-istic—Ideally, for equal increments ofvalve plug travel, the change in flowrate regarding travel may be ex-pressed as a constant percent of theflow rate at the time of the change.The change in flow rate observed re-garding travel will be relatively smallwhen the valve plug is near its seatand relatively high when the valveplug is nearly wide open. Therefore, avalve with an inherent equal-percent-
Chapter 3. Valve and Actuator Types
60
Figure 3-30. Typical Construction to Provide Quick-OpeningFlow Characteristic
A7100/IL
age flow characteristic provides pre-cise throttling control through the low-er portion of the travel range andrapidly increasing capacity as thevalve plug nears the wide-open posi-tion. Valves with equal-percentageflow characteristics are used on pres-sure control applications, on applica-tions where a large percentage of thepressure drop is normally absorbed bythe system itself with only a relativelysmall percentage available at the con-trol valve and on applications wherehighly varying pressure drop condi-tions can be expected. In most physi-cal systems, the inlet pressure de-creases as the rate of flow increases,and an equal percentage characteris-tic is appropriate. For this reason,equal percentage is the most commonvalve characteristic.
Quick-Opening Flow Characteris-tic—A valve with a quick opening flowcharacteristic provides a maximumchange in flow rate at low travels. Thecurve is basically linear through thefirst 40 percent of valve plug travel,then flattens out noticeably to indicatelittle increase in flow rate as travel ap-proaches the wide-open position.Control valves with quick-opening flowcharacteristics are often used for on/off applications where significant flowrate must be established quickly asthe valve begins to open. Conse-quently, they are often used in reliefvalve applications. Quick-openingvalves can also be selected for manyof the same applications for which lin-ear flow characteristics are recom-mended, because the quick-openingcharacteristic is linear up to about 70
percent of maximum flow rate. Lineari-ty decreases sharply after flow areagenerated by valve plug travel equalsthe flow area of the port. For a typicalquick-opening valve (figure 3-30), thisoccurs when valve plug travel equalsone-fourth of port diameter.
Valve Plug GuidingAccurate guiding of the valve plug isnecessary for proper alignment withthe seat ring and efficient control ofthe process fluid. The common meth-ods used are listed below and theirnames are generally self descriptive.
Cage Guiding: The outside diameterof the valve plug is close to the insidewall surface of the cylindrical cagethroughout the travel range. Sincebonnet, cage, and seat ring are self-aligning on assembly, correct valveplug/seat ring alignment is assuredwhen valve closes (figure 3-15).
Top Guiding: Valve plug is aligned bya single guide bushing in the bonnetor valve body (figure 3-4), or by pack-ing arrangement.
Stem Guiding: Valve plug is alignedwith the seat ring by a guide bushingin the bonnet that acts on the valveplug stem (figure 3-3, left view).
Top-and-Bottom Guiding: Valve plugis aligned by guide bushings in thebonnet and bottom flange (figure 3-7).
Port Guiding: Valve plug is alignedby the valve body port. This construc-tion is typical for control valves usingsmall-diameter valve plugs with fluted
Chapter 3. Valve and Actuator Types
61
CAGEGASKET
SHIM
SPIRALWOUNDGASKET
RESTRICTEDTRIMADAPTORS
OPTIONAL RESTRICTED TRIM
BONNETGASKET
Figure 3-31. Adapter Method for Providing Reduced Flow Capacity
W2001/IL
skirt projections to control low flowrates (figure 3-3, right view).
Restricted-CapacityControl Valve TrimMost control valve manufacturers canprovide valves with reduced- or re-stricted-capacity trim parts. The re-duced flow rate might be desirable forany of the following reasons:
� Restricted capacity trim maymake it possible to select a valvebody large enough for increased fu-ture flow requirements, but with trimcapacity properly sized for presentneeds.
� Valves can be selected for ade-quate structural strength, yet retainreasonable travel/capacity relation-ship.
� Large bodies with restricted ca-pacity trim can be used to reduce inletand outlet fluid velocities.
� Purchase of expensive pipelinereducers can be avoided.
� Over-sizing errors can be cor-rected by use of restricted capacitytrim parts.
Conventional globe-style valve bodiescan be fitted with seat rings withsmaller port size than normal andvalve plugs sized to fit those smallerports. Valves with cage-guided trimoften achieve the reduced capacityeffect by using valve plug, cage, andseat ring parts from a smaller valvesize of similar construction and adapt-er pieces above the cage and belowthe seat ring to mate those smallerparts with the valve body (figure 3-31).Because reduced capacity service isnot unusual, leading manufacturersprovide readily available trim partcombinations to perform the requiredfunction. Many restricted capacity trimcombinations are designed to furnishapproximately 40% of full-size trim ca-pacity.
Actuators
Pneumatically operated control valveactuators are the most popular type inuse, but electric, hydraulic, and manu-al actuators are also widely used. Thespring-and-diaphragm pneumatic ac-tuator is most commonly specified dueto its dependability and simplicity ofdesign. Pneumatically operated pistonactuators provide high stem force out-put for demanding service conditions.Adaptations of both spring-and-dia-phragm and pneumatic piston actua-
Chapter 3. Valve and Actuator Types
62
Figure 3-32. Diaphragm Actuators
W0363/IL DIRECT-ACTING REVERSE-ACTINGW0364/IL
tors are available for direct installationon rotary-shaft control valves.
Electric and electro-hydraulic actua-tors are more complex and more ex-pensive than pneumatic actuators.They offer advantages where no airsupply source is available, where lowambient temperatures could freezecondensed water in pneumatic supplylines, or where unusually large stemforces are needed. A summary fol-lows, discussing the design and char-acteristics of popular actuator styles.
Diaphragm Actuators
� Pneumatically operated dia-phragm actuators use air supply fromcontroller, positioner, or other source.
� Various styles include: direct-acting (increasing air pressure pushesdown diaphragm and extends actuatorstem, figure 3-32); reverse-acting (in-creasing air pressure pushes up dia-phragm and retracts actuator stem,figure 3-32); reversible (actuators that
Figure 3-33. Field-ReversibleMulti-Spring Actuator
W8486-3
can be assembled for either direct orreverse action, figure 3-33); direct-act-ing unit for rotary valves (increasing
Chapter 3. Valve and Actuator Types
63
Figure 3-34. Diaphragm Actua-tor for Rotary Shaft Valves
W4742-1/IL
air pressure pushes down on dia-phragm, which may either open orclose the valve, depending on orienta-tion of the actuator lever on the valveshaft, figure 3-34).
� Net output thrust is the differ-ence between diaphragm force andopposing spring force.
� Molded diaphragms provide lin-ear performance and increased trav-els.
� Output thrust required and sup-ply air pressure available dictate size.
� Diaphragm actuators are simple,dependable, and economical.
Piston Actuators
� Piston actuators are pneumati-cally operated using high-pressureplant air to 150 psig, often eliminatingthe need for supply pressure regula-tor.
� Piston actuators furnish maxi-mum thrust output and fast strokingspeeds.
Figure 3-35. Control Valve withDouble-Acting Piston Actuator
W0320-1/IL
� Piston actuators are double act-ing to give maximum force in both di-rections, or spring return to providefail-open or fail-closed operation(fig-ure 3-35).
� Various accessories can be in-corporated to position a double-actingpiston in the event of supply pressurefailure. These include pneumatic tripvalves and lock-up systems.
� Also available are hydraulicsnubbers, handwheels, and units with-out yokes, which can be used to oper-ate butterfly valves, louvers, and simi-lar industrial equipment.
� Other versions for service onrotary-shaft control valves include asliding seal in the lower end of the cyl-inder. This permits the actuator stemto move laterally as well as up anddown without leakage of cylinder pres-sure. This feature permits direct con-nection of the actuator stem to the ac-tuator lever mounted on the rotaryvalve shaft, thereby eliminating onejoint or source of lost motion.
Chapter 3. Valve and Actuator Types
64
Figure 3-36. Control Valve withDouble-Acting Electrohydraulic
Actuator and Handwheel
W2286/IL
Electrohydraulic Actuators
� Electrohydraulic actuators re-quire only electrical power to the mo-tor and an electrical input signal fromthe controller (figure 3-36).
� Electrohydraulic actuators areideal for isolated locations wherepneumatic supply pressure is notavailable but where precise control ofvalve plug position is needed.
� Units are normally reversible bymaking minor adjustments and mightbe self-contained, including motor,pump, and double-acting hydraulicallyoperated piston within a weatherproofor explosion-proof casing.
Manual Actuators
� Manual actuators are usefulwhere automatic control is not re-quired, but where ease of operationand good manual control is still neces-sary (figure 3-37). They are oftenused to actuate the bypass valve in athree-valve bypass loop around con-trol valves for manual control of theprocess during maintenance or shut-down of the automatic system.
� Manual actuators are availablein various sizes for both globe-stylevalves and rotary-shaft valves.
� Dial-indicating devices are avail-able for some models to permit accu-rate repositioning of the valve plug ordisk.
� Manual actuators are much lessexpensive than automatic actuators.
Rack and Pinion ActuatorsRack and pinion designs provide acompact and economical solution forrotary shaft valves (figure 3-38). Be-cause of backlash, they are typicallyused for on-off applications or whereprocess variability is not a concern.
Electric ActuatorsTraditional electric actuator designsuse an electric motor and some formof gear reduction to move the valve.Through adaptation, these mecha-nisms have been used for continuouscontrol with varying degrees of suc-cess. To date, electric actuators havebeen much more expensive thanpneumatic for the same performancelevels. This is an area of rapid techno-logical change, and future designsmay cause a shift towards greater useof electric actuators.
Chapter 3. Valve and Actuator Types
65
Figure 3-37. Typical Manual Actuators
W8176-1
FOR SLIDING-STEM VALVES FOR ROTARY-SHAFT VALVES
W0595/IL
Figure 3-38. Typical Rack and PinionActuator
W6957/IL
Chapter 3. Valve and Actuator Types
66
67
Chapter 4
Control Valve Accessories
This chapter offers information on digi-tal valve controllers, analog position-ers, boosters, and other control valveaccessories.
PositionersPneumatically operated valves de-pend on a positioner to take an inputsignal from a process controller andconvert it to valve travel. These instru-ments are available in three configura-tions:
1. Pneumatic Positioners—A pneu-matic signal (usually 3-15 psig) is sup-plied to the positioner. The positionertranslates this to a required valveposition and supplies the valve actua-tor with the required air pressure tomove the valve to the correct position.
2. Analog I/P Positioner—This posi-tioner performs the same function asthe one above, but uses electrical cur-
rent (usually 4-20 mA) instead of airas the input signal.
3. Digital Controller—Although this in-strument functions very much as theAnalog I/P described above, it differsin that the electronic signal conversionis digital rather than analog. The digi-tal products cover three categories.
� Digital Non-Communicating—Acurrent signal (4-20 mA) is supplied tothe positioner, which both powers theelectronics and controls the output.
� HART—This is the same as thedigital non-communicating but is alsocapable of two-way digital commu-nication over the same wires used forthe analog signal.
� Fieldbus—This type receivesdigitally based signals and positionsthe valve using digital electronic cir-cuitry coupled to mechanical compo-nents. An all-digital control signal re-
Chapter 4. Control Valve Accessories
68
Figure 4-1. Modern Control ValvesUtilizing Digital Valve Controllers
W8861
W8119-1
places the analog control signal.Additionally, two-way digital commu-nication is possible over the samewires. Fieldbus technologies benefitthe end user by enabling improvedcontrol architecture, product capabilityand reduced wiring.
Use of a single, integrated analog I/Ppositioner or digital controller (figure4-1) instead of a combination of pneu-matic positioner and transducer (twoinstruments) results in lower installedcost.
The ability to embed software com-mands into the memory of the devicerepresents the real difference be-tween digital and analog I/P seg-ments. This allows automatic configu-ration and setup of the valve when
equipped with a digital controller. Mostimportantly, it allows two-way commu-nication for process, valve, and instru-ment diagnostics.
Users purchase digital valve control-lers for several reasons:
� Reduced cost of loop commis-sioning, including installation and cal-ibration.
� Use of diagnostics to maintainloop performance levels.
� Improved process control accu-racy that reduces process variability.
Two aspects of digital valve control-lers make them particularly attractive:
� Automatic calibration and config-uration. Considerable time savingsare realized over traditional zero andspanning.
� Valve diagnostics. Through theDistributed Control System (DCS), PCsoftware tools, or handheld communi-cators, users can diagnose the healthof the valve while it is in the line.
FIELDVUE� instruments enable newdiagnostic capabilities that can be ac-cessed remotely. This single elementrequires a look at the potential impactof the technology as it applies to con-trol valves.
An in-plant person, with the aid of theFlowScanner� system, can diagnosethe health of a valve through a seriesof off-line tests. The FlowScanner sys-tem consists of a portable, ruggedizedcomputer and travel and pressuresensors. The sensors are connectedto the valve to enable diagnostic tests,which are conducted with the valveoff-line. A skilled maintenance techni-cian can determine whether to leavethe valve in the line or to remove thevalve for repair.
Digital instruments allow an extensionof this service with added enhance-ments:
� Because sensors are part of theinstrument, tests can be run easily atappropriate times.
Chapter 4. Control Valve Accessories
69
Figure 4-2. Positioner Schematic for Diaphragm Actuator
OUTPUT TODIAPHRAGM
RELAY
INSTRUMENT
BELLOWS
FEEDBACKAXIS
PIVOT
NOZZLE
FLAPPER
DIRECT ACTIONQUADRANT
INPUT AXIS
CAM
REVERSE ACTIONQUADRANT
BEAM
ACTUATORVALVE STEMCONNECTION
SUPPLY
22A7965-AA2453-2 / IL
� It is now possible to diagnosethe health of a valve remotely viaHART or Foundation fieldbus.
� On-line diagnostics enable pre-dictive maintenance without disruptingthe process.
These additional elements are ex-tremely important. The remote capa-bility allows monitoring valves. Thosewho make, supply and service valvesfor a living now assist the customer inthe diagnosis of valve condition to alevel never before possible. Predictivemaintenance offers additional savingsfor the customer. It is now possible tosee the performance of the valve as itoperates. Watching performance de-cline over time enables the user topredict when replacement or repair isnecessary.
Other Control ValveAccessoriesFigure 4-5 illustrates a top-mountedhandwheel for a direct-acting dia-phragm actuator. This unit can beused as an adjustable travel stop tolimit travel in the upward direction orto manually close push-down-to-closevalves.
Figure 4-6 illustrates a top-mountedhandwheel for a reverse-acting dia-phragm actuator. This unit can beused as an adjustable travel stop tolimit travel in the downward directionor to manually close push-down-to-open valves.
Limit SwitchesLimit switches operate discrete inputsto a distributed control system, signallights, small solenoid valves, electricrelays, or alarms. The cam-operatedtype (figure 4-7) is typically used with
Chapter 4. Control Valve Accessories
70
Figure 4-3. Positioner Schematic for Piston Actuator
A1304/IL
INPUT SIGNAL
BYPASS RESTRICTIONADJUSTING SCREW
BYPASSRESTRICTION
SUPPLYPORT
OUTPUT TOACTUATOR
SUPPLY
EXHAUST
EXHAUSTPORT
DIAPHRAGMS
W0679-1/IL
Figure 4-4. Volume Booster
Chapter 4. Control Valve Accessories
71
Figure 4-5. Top-Mounted Hand-wheel for Direct-Acting Diaphragm
Actuator
W0368-1/IL
Figure 4-6. Top-Mounted Hand-wheel for Reverse-Acting Dia-
phragm Actuator
W0369-1/IL
two to four individual switches oper-ated by movement of the valve stem.An assembly that mounts on the sideof the actuator houses the switches.Each switch adjusts individually andcan be supplied for either alternatingcurrent or direct current systems. Oth-er styles of valve-mounted limitswitches are also available.
Figure 4-7. Cam-OperatedLimit Switches
A7095/IL
W2078/IL
Solenoid Valve Manifold
The actuator type and the desired fail-safe operation determine the selectionof the proper solenoid valve (figure4-8). The solenoids can be used ondouble-acting pistons or single-actingdiaphragm actuators.
Supply Pressure Regulator
Supply pressure regulators (figure4-9), commonly called airsets, reduceplant air supply to valve positionersand other control equipment. Com-mon reduced-air-supply pressures are20, 35 and 60 psig. The regulatormounts integrally to the positioner, ornipple-mounts or bolts to the actuator.
Chapter 4. Control Valve Accessories
72
Figure 4-8. Solenoid Valve
W7007/IL
Figure 4-9. Supply Pressure Regulatorwith Filter and Moisture Trap
W0047/IL
Pneumatic Lock-Up SystemsPneumatic lock-up systems (figure4-10) are used with control valves tolock in existing actuator loading pres-
sure in the event of supply pressurefailure. These devices can be usedwith volume tanks to move the valveto the fully open or closed position onloss of pneumatic air supply. Normaloperation resumes automatically withrestored supply pressure. Functionallysimilar arrangements are available forcontrol valves using diaphragm actua-tors.
Fail-Safe Systems for PistonActuators
In these fail-safe systems (figure4-11), the actuator piston moves tothe top or bottom of the cylinder whensupply pressure falls below a pre-de-termined value. The volume tank,charged with supply pressure, pro-vides loading pressure for the actuatorpiston when supply pressure fails,thus moving the piston to the desiredposition. Automatic operation re-sumes, and the volume tank is re-charged when supply pressure is re-stored to normal.
Electro-Pneumatic Transducers
Figure 4-12 illustrates an electro-pneumatic transducer. The transducerreceives a direct current input signaland uses a torque motor, nozzle-flap-per, and pneumatic relay to convertthe electric signal to a proportionalpneumatic output signal. Nozzle pres-sure operates the relay and is piped tothe torque motor feedback bellows toprovide a comparison between inputsignal and nozzle pressure. Asshown, the transducer can bemounted directly on a control valveand operate the valve without need foradditional boosters or positioners.
Chapter 4. Control Valve Accessories
73
Figure 4-10. Lock-Up System Schematic for Piston Actuator
35A6998-CA2285-4/IL
Figure 4-11. Typical Schematic of a “Fail-Safe” System
35A6996-CA2283-4/IL
Chapter 4. Control Valve Accessories
74
Figure 4-12. Electro-PneumaticTransducer Mounted on a Dia-phragm-Actuated Control Valve
ELECTRO-PNEUMATICTRANSDUCER
W8723−1
Electro-Pneumatic ValvePositioners
Electro-pneumatic positioners (figure4-13) are used in electronic controlloops to operate pneumatic dia-phragm control valve actuators. Thepositioner receives a 4 to 20 mA DCinput signal, and uses an I/P convert-er, nozzle-flapper, and pneumaticrelay to convert the input signal to apneumatic output signal. The outputsignal is applied directly to the actua-tor diaphragm, producing valve plugposition that is proportional to the in-put signal. Valve plug position is me-chanically fed back to the torque com-parison of plug position and inputsignal. Split-range operation capabilitycan provide full travel of the actuatorwith only a portion of the input signalrange.
Diagnostics
Digital valve controllers incorporatepredefined instrument and valve diag-
Figure 4-13. Electro-PneumaticPositioner on Diaphragm Actuator
W4930/IL
nostics within firmware to providealerts if there are problems with instru-ment mounting, electronics, hardwareor valve performance.
HART-based handheld field communi-cators when connected to the digitalvalve controllers enable user-config-ured alerts and alarms. These flagsprovide notification of current statusand potential valve and instrumentproblems. Typical alerts include traveldeviation, travel limit, cycle count andtravel accumulation.
AMS ValveLink� software allowstests that identify problems with theentire control valve assembly. Usingthe valve stem travel feedback, actua-tor pressure sensor and other sensorson the instrument, the health of thecontrol valve can be evaluated whilethe valve is still in service and fully op-erational. This helps to pinpoint prob-lems before the equipment fails, with-out disrupting the process.
75
Chapter 5
Control Valve Selection
Control valves handle all kinds offluids at temperatures from the cryo-genic range to well over 1000�F(538�C). Selection of a control valvebody assembly requires particularconsideration to provide the bestavailable combination of valve bodystyle, material, and trim constructiondesign for the intended service. Ca-pacity requirements and system oper-ating pressure ranges also must beconsidered in selecting a control valveto ensure satisfactory operation with-out undue initial expense.
Reputable control valve manufactur-ers and their representatives are dedi-cated to helping select the controlvalve most appropriate for the existingservice conditions. Because there arefrequently several possible correctchoices for an application, it is impor-tant that all the following informationbe provided:
� Type of fluid to be controlled
� Temperature of fluid
� Viscosity of fluid
� Specific gravity of fluid
� Flow capacity required (maxi-mum and minimum)
� Inlet pressure at valve (maxi-mum and minimum)
� Outlet pressure (maximum andminimum)
� Pressure drop during normalflowing conditions
� Pressure drop at shutoff
� Maximum permissible noise lev-el, if pertinent, and the measurementreference point
� Degrees of superheat or exis-tence of flashing, if known
Chapter 5. Control Valve Selection
76
� Inlet and outlet pipeline size andschedule
� Special tagging information re-quired
� Body Material (ASTM A216grade WCC, ASTM A217 grade WC9,ASTM A351 CF8M, etc.)
� End connections and valve rat-ing (screwed, Class 600 RF flanged,Class 1500 RTJ flanges, etc.)
� Action desired on air failure(valve to open, close, or retain lastcontrolled position)
� Instrument air supply available
� Instrument signal (3 to 15 psig, 4to 20 mA, Hart, etc.)
In addition the following informationwill require the agreement of the userand the manufacturer depending onthe purchasing and engineering prac-tices being followed.
� Valve type number
� Valve size
� Valve body construction (angle,double-port, butterfly, etc.)
� Valve plug guiding (cage-style,port-guided, etc.)
� Valve plug action(push-down-to-close or push-down-to-open)
� Port size (full or restricted)
� Valve trim materials required
� Flow action (flow tends to openvalve or flow tends to close valve)
� Actuator size required
� Bonnet style (plain, extension,bellows seal, etc.)
� Packing material (PTFE V-ring,laminated graphite, environmentalsealing systems, etc.)
� Accessories required (positioner,handwheel, etc.)
Some of these options have been dis-cussed in previous chapters of thisbook, and others will be explored inthis and following chapters.
VALVE SELECTION PROCESS
DETERMINE SERVICE CONDITIONS� (P1, ∆P, Q, T1, Fluid Properties, Allow-able Noise, etc).� Select appropriate ANSI Pressure Classrequired for valve body and trim.
CALCULATE PRELIMINARY Cv REQUIRED� Check noise and cavitation levels
SELECT TRIM TYPE� If no noise or cavitation indication, choosestandard trim.� If aerodynamic noise is high, choose Whis-per Trim�.� If liquid noise is high and/or cavitation is in-dicated, choose Cavitrol� III trim.
SELECT VALVE BODY AND TRIM SIZE� Select valve body and trim size with re-quired Cv. � Note travel, trim group, and shutoff options.
SELECT TRIM MATERIALSSelect trim materials for your application;make sure trim selected is available in thetrim group for the valve size selected.
OPTIONSConsider options on shutoff, stem packing,etc.
Valve Body MaterialsBody material selection is usuallybased on the pressure, temperature,
Chapter 5. Control Valve Selection
77
corrosive properties, and erosiveproperties of the flow media. Some-times a compromise must be reachedin selecting a material. For instance, amaterial with good erosion resistancemay not be satisfactory because ofpoor corrosion resistance when han-dling a particular fluid.
Some service conditions require useof exotic alloys and metals to with-stand particular corrosive properties ofthe flowing fluid. These materials aremuch more expensive than commonmetals, so economy may also be afactor in material selection. Fortunate-ly, the majority of control valve ap-
plications handle relatively non-corro-sive fluids at reasonable pressuresand temperatures. Therefore, castcarbon steel is the most commonlyused valve body material and can pro-vide satisfactory service at much low-er cost than the exotic alloy materials.
Specifications have been developedfor ordering highly corrosion resistant,high nickel alloy castings. Thesespecifications represent solutions toproblems encountered with those al-loys. These problems included unac-ceptable corrosion resistancecompared to the wrought materials,poor weldability, poor casting integrity
Designations for the High Nickel Alloys
CastingDesignations
Equivalent WroughtTradenames
GenericDesignations
UNS Numbers forWrought
EquivalentsCF3 304L S30403
CF8 304 S30400
CF3M 316L S31603
CF8M 316 S31600
CG8M 317 S31700
CK3MCuN Avesta 254 SMO(1) Alloy 254 S31254
CN7M Carpenter 20Cb3(2) Alloy 20 N08020
CU5MCuC Incoloy 825(3) Alloy 825 N08825
CW12MW Obsolete Hastelloy C(4) Alloy C N10002
CW2M New Hastelloy C(4) Alloy C276 N10276
CX2MW Hastelloy C22(4) Alloy C22 N06022
CW6MC Inconel 625(3) Alloy 625 N06625
CY40 Inconel 600(3) Alloy 600 N06600
CZ100 Nickel 200 Alloy 200 N02200
LCB LCB J03003
LCC LCC J02505
M25S S-Monel(3) Alloy S
M35-1 Monel 400(3) Alloy 400 N04400
N12MV Obsolete Hastelloy B(4) Alloy B N10001
N7M Hastelloy B2(4) Alloy B2 N10665
WCB WCB J03002
WCC WCC J025031. Trademark of Avesta AB2. Tradenames of Carpenter Technology3. Tradenames of Special Metals Corp.4. Tradename of Haynes International
Chapter 5. Control Valve Selection
78
and unacceptable lead times. Thespecifications include foundry qualifi-cation, dedicated pattern equipment,pattern alloy qualification, heat qualifi-cation, and detailed controls on rawmaterial, visual inspection, weld re-pairs, heat treatment, and non-de-structive testing. A listing of these ex-otic alloys appears in theDesignations for the High Nickel Al-loys Table.
The following descriptions and tablesprovide basic information on variouspopular castable materials used forcontrol valve bodies. ASTM materialdesignations are included. Use ofproper ASTM designations is consid-
ered good practice and is encouragedin specifying materials, particularly forpressure-containing parts. Additionalengineering data on these and othermaterials is included in Chapter 10.
Cast Carbon Steel (ASTM A216Grade WCC)—WCC is the most pop-ular steel material used for valve bod-ies in moderate services such as air,saturated or superheated steam,non-corrosive liquids and gases. WCCis not used above 800�F (427�C) asthe carbon rich phase might be con-verted to graphite. It can be weldedwithout heat treatment unless nominalthickness exceeds 1-1/4 inches (32mm).
Pressure-Temperature Ratings for Standard ClassASTM A216 Grade WCC Valves
(in accordance with ASME B16.34)
TEMPERATURE, �F
WORKING PRESSURES BY CLASS, PSIG
150 300 600 900 1500
Psig
−20 to 100 290 750 1,500 2,250 3,750
200 260 750 1,500 2,250 3,750
300 230 730 1,455 2,185 3,640
400 200 705 1,410 2,115 3,530
500 170 665 1,330 1,995 3,325
600 140 605 1,210 1,815 3,025
650 125 590 1,175 1,765 2,940
700 110 570 1,135 1,705 2,840
750 95 505 1,010 1,510 2,520
800 80 410 825 1,235 2,060
�C Bar
−29 to 38 20 52 103 155 259
93 18 52 103 155 259
149 16 50 100 151 251
204 14 49 97 146 243
260 12 46 92 138 229
316 10 42 83 125 209
343 9 41 81 122 203
371 8 39 78 118 196
399 7 35 70 104 174
427 6 28 57 85 142
Chapter 5. Control Valve Selection
79
Cast Chromium-Molybdenum Steel(ASTM A217 Grade WC9)—This isthe standard Cr-Mo grade. WC9 hasreplaced C5 as the standard becauseof superior casting and welding prop-erties. WC9 has successfully replacedC5 in most applications, especially in
steam and boiler feedwater service.The chromium and molybdenum pro-vide erosion-corrosion and creep re-sistance, making it useful to 1100�F(593�C). WC9 requires preheating be-fore welding and heat treatment afterwelding.
Pressure-Temperature Ratings for Standard ClassASTM A217 Grade WC9 Valves
(in accordance with ASME B16.34)
TEMPERATURE,�F
WORKING PRESSURES BY CLASS, PSIG
150 300 600 900 1500
−20 to 100 290 750 1,500 2,250 3,750
200 260 750 1,500 2,250 3,750
300 230 730 1,455 2,185 3,640
400 200 705 1,410 2,115 3,530
500 170 665 1,330 1,995 3,325
600 140 605 1,210 1,815 3,025
650 125 590 1,175 1,765 2,940
700 110 570 1,135 1,705 2,840
750 95 530 1,065 1,595 2,660
800 80 510 1,015 1,525 2,540
850 65 485 975 1,460 2,435
900 50 450 900 1,350 2,245
950 35 375 755 1,130 1,885
1000 20 260 520 780 1,305
1050 20(1) 175 350 525 875
1100 20(1) 110 220 330 550
�C Bar
−29 to 38 20 52 103 155 259
93 18 52 103 155 259
149 16 50 100 151 251
204 14 49 97 146 243
260 12 46 92 138 229
316 10 42 83 125 209
343 9 41 81 122 203
371 8 39 78 118 196
399 7 37 73 110 183
427 6 35 70 105 175
454 4 33 67 101 168
482 3 31 62 93 155
510 2 26 52 78 130
538 1 18 36 54 90
565 1(1) 12 24 36 60
593 1(1) 8 15 23 381. For welding end valves only. Flanged end ratings terminate at 1000�F.
Chapter 5. Control Valve Selection
80
Cast Chromium-Molybdenum Steel(ASTM A217 Grade C5)—In the pastC5 was commonly specified for ap-plications requiring chromium-molyb-denum steels. However, this materialis somewhat difficult to cast and has atendency to crack when welded. WC9
has successfully replaced C5 in manyapplications, but C5 continues to beused in refinery applications where itshigher chromium content providesbetter resistance to high-temperaturesulfidic corrosion.
Pressure-Temperature Ratings for Standard ClassASTM A217 Grade C5 Valves
(in accordance with ASME B16.34)
TEMPERATURE,�F
WORKING PRESSURE BY CLASS, PSIG
150 300 600 900 1500
−20 to 100 290 750 1,500 2,250 3,750
200 260 745 1,490 2,235 3,725
300 230 715 1,430 2,150 3,580
400 200 705 1,410 2,115 3,530
500 170 665 1,330 1,995 3,325
600 140 605 1,210 1,815 3,025
650 125 590 1,175 1,765 2,940
700 110 570 1,135 1,705 2,840
750 95 530 1,055 1,585 2,640
800 80 510 1,015 1,525 2,540
850 65 485 965 1,450 2,415
900 50 370 740 1,110 1,850
950 35 275 550 825 1,370
1000 20 200 400 595 995
1050 20(1) 145 290 430 720
1100 20(1) 100 200 300 495
�C Bar
−29 to 38 20 52 103 155 259
93 18 51 103 154 257
149 16 49 99 148 247
204 14 49 97 146 243
260 12 46 92 138 229
316 10 42 83 125 209
343 9 41 81 122 203
371 8 39 78 118 196
399 7 37 73 109 182
427 6 35 70 105 175
454 4 31 67 100 167
482 3 26 51 77 128
510 2 19 38 57 94
538 1 14 28 41 89
565 1(1) 10 20 30 50
593 1(1) 7 14 21 34
1. For welding end valves only. Flanged end ratings terminate at 1000�F.
Chapter 5. Control Valve Selection
81
Cast Type 304L Stainless Steel(ASTM A351 Grade CF3)—This is agood material offering for chemicalservice valves. 304L is the best mate-
rial for nitric acid and certain otherchemical service applications. Opti-mum corrosion resistance is retainedeven in the as-welded condition.
Pressure-Temperature Ratings for Standard ClassASTM A351 Grade CF3 Valves
(in accordance with ASME B16.34)
TEMPERATUREWORKING PRESSURES BY CLASS
150 300 600 900 1500
�F Psig
−20 to 100 275 720 1,440 2,160 3,600
200 230 600 1,200 1,800 3,000
300 205 540 1,080 1,620 2,700
400 190 495 995 1,490 2,485
500 170 465 930 1,395 2,330
600 140 435 875 1,310 2,185
650 125 430 860 1,290 2,150
700 110 425 850 1,275 2,125
750 95 415 830 1,245 2,075
800 80 405 805 1,210 2,015
850 65 395 790 1,190 1,980
900 50 390 780 1,165 1,945
950 35 380 765 1,145 1,910
1000 20 320 640 965 1,605
1050 20(1) 310 615 925 1,545
1100 20(1) 255 515 770 1,285
1150 20(1) 200 400 595 995
1200 20(1) 155 310 465 770
1250 20(1) 115 225 340 565
1300 20(1) 85 170 255 430
1350 20(1) 60 125 185 310
1400 20(1) 50 95 145 240
1450 15(1) 35 70 105 170
1500 10(1) 25 55 80 135
�C Bar
−29 to 38 19 50 99 149 248
93 16 41 83 124 207
149 14 37 74 112 186
204 13 34 69 103 171
260 12 32 64 96 161
316 10 30 60 90 151
343 9 30 59 89 148
371 8 29 59 88 147
399 7 29 57 86 143
427 6 28 56 83 139
(continued)
Chapter 5. Control Valve Selection
82
Pressure-Temperature Ratings for Standard ClassASTM A351 Grade CF3 Valves
(in accordance with ASME B16.34) (continued)
TEMPERATUREWORKING PRESSURES BY CLASS
TEMPERATURE1500900600300150
�C Bar
454 4 27 54 82 137
482 3 27 54 80 134
510 2 26 53 79 132
538 1 22 44 67 111
565 1(1) 21 42 64 107
593 1(1) 18 36 53 89
621 1(1) 14 28 41 69
649 1(1) 11 21 32 53
676 1(1) 8 16 23 39
704 1(1) 6 12 18 30
732 1(1) 4 9 13 21
760 1(1) 3 7 10 17
788 1(1) 2 5 70 12
815 1(1) 2 4 6 91. For welding end valves only. Flanged end ratings terminate at 1000�F.
Cast Type 316 Stainless Steel(ASTM A351 Grade CF8M)—This isthe industry standard stainless steelbody material. The addition of molyb-denum gives Type 316 greater resist-ance to corrosion, pitting, creep andoxidizing fluids compared to 304. Ithas the widest temperature range ofany standard material: −425�F(−254�C) to 1500�F (816�C). Therough castings are heat treated to pro-vide maximum corrosion resistance.
Cast Type 317 Stainless Steel(ASTM A479 Grade UNSS31700)—S31700 is essentiallyS31600 with the nickel and molybde-num contents increased 1% each.This affords greater resistance to pit-
ting than is obtained with S31600.Like S31600, S31700 is completelyaustenitic and non-magnetic. Becauseits strength is similar to that ofS31600, it has the samepressure-temperature allowances.CG8M is the casting version ofS31700. It contains considerableamounts of ferrite (15 to 35%), andtherefore is partially to strongly mag-netic. In general, Type S31700 hasbetter corrosion resistance thanS31600 in certain environments be-cause of its higher molybdenum con-tent. It has excellent resistance to di-gester liquor, dry chlorine dioxide andmany other pulp and paper environ-ments.
Pressure-Temperature Ratings for Standard ClassASTM A351 Grades CF8M and CG8M(1) Valves
(in accordance with ASME B16.34)
TEMPERATUREWORKING PRESSURES BY CLASS
150 300 600 900 1500
�F Psig
−20 to 100 275 720 1,440 2,160 3,600
(continued)
Chapter 5. Control Valve Selection
83
Pressure-Temperature Ratings for Standard ClassASTM A351 Grades CF8M and CG8M(1) Valves(in accordance with ASME B16.34) (continued)
TEMPERATUREWORKING PRESSURES BY CLASS
TEMPERATURE1500900600300150
�F Psig
200 235 620 1,240 1,860 3,095
300 215 560 1,120 1,680 2,795
400 195 515 1,025 1,540 2,570
500 170 480 955 1,435 2,390
600 140 450 900 1,355 2,255
650 125 445 890 1,330 2,220
700 110 430 870 1,305 2,170
750 95 425 855 1,280 2,135
800 80 420 845 1,265 2,110
850 65 420 835 1,255 2,090
900 50 415 830 1,245 2,075
950 35 385 775 1,160 1,930
1000 20 350 700 1,050 1,750
1050 20(2) 345 685 1,030 1,720
1100 20(2) 305 610 915 1,525
1150 20(2) 235 475 710 1,185
1200 20(2) 185 370 555 925
1250 20(2) 145 295 440 735
1300 20(2) 115 235 350 585
1350 20(2) 95 190 290 480
1400 20(2) 75 150 225 380
1450 20(2) 60 115 175 290
1500 20(2) 40 85 125 205
�C Bar
−29 to 38 19 50 99 149 248
93 16 43 85 128 213
149 15 39 77 116 193
204 13 36 71 106 177
260 12 33 66 99 165
316 10 31 62 93 155
343 9 31 61 92 153
371 8 29 60 90 150
399 7 29 59 88 147
427 6 29 58 87 145
454 4 29 58 87 144
482 3 27 57 86 143
510 2 24 53 80 133
538 1 24 48 72 121
565 1(2) 21 47 71 119
(continued)
Chapter 5. Control Valve Selection
84
Pressure-Temperature Ratings for Standard ClassASTM A351 Grades CF8M and CG8M(1) Valves(in accordance with ASME B16.34) (continued)
TEMPERATUREWORKING PRESSURES BY CLASS
TEMPERATURE1500900600300150
�C Bar
593 1(2) 16 42 63 105
621 1(2) 13 33 49 82
649 1(2) 10 26 38 64
676 1(2) 8 20 30 51
704 1(2) 6 16 24 40
732 1(2) 4 13 20 33
760 1(2) 3 10 16 26
788 1(2) 2 8 12 20
815 1(2) 2 6 9 141. CG8M is limited to 1000�F (538�C)2. For welding end valves only. Flanged end ratings terminate at 1000�F (538�C).
Cast Iron (ASTM A126)—Cast iron isan inexpensive, non-ductile materialused for valve bodies controlling
steam, water, gas and non-corrosivefluids.
Pressure-Temperature Ratings for ASTM A216 Cast Iron Valves(in accordance with ASME/ANSI B16.1)
TEMPERATURE
CLASS 125 CLASS 250
ASTM A 216 ASTM A 216
Class A Class B Class A Class B
NPS1-12
NPS1-12
NPS14-24
NPS1-12
NPS1-12
NPS14-24
�F Psig
−20 to 150 175 200 150 400 500 300
200 165 190 135 370 460 280
225 155 180 130 355 440 270
250 150 175 125 340 415 260
275 145 170 120 325 395 250
300 140 165 110 310 375 240
325 130 155 105 295 355 230
353 125 150 100 280 335 220
375 - - - 145 - - - 265 315 210
406 - - - 140 - - - 250 290 200
425 - - - 130 - - - - - - 270 - - -
450 - - - 125 - - - - - - 250 - - -
�C Bar
−29 to 66 12 14 10 28 34 21
93 11 13 9 26 32 19
107 11 12 9 24 30 19
121 10 12 9 23 29 18
(continued)
Chapter 5. Control Valve Selection
85
Pressure-Temperature Ratings for ASTM A216 Cast Iron Valves(in accordance with ASME/ANSI B16.1) (continued)
TEMPERATURE
CLASS 250CLASS 125
TEMPERATURE
ASTM A 216ASTM A 216TEMPERATURE Class BClass AClass BClass ATEMPERATURE
NPS14-24
NPS1-12
NPS1-12
NPS14-24
NPS1-12
NPS1-12
�C Bar
135 10 12 8 22 27 17
149 10 11 8 21 26 17
163 9 11 7 20 24 16
178 9 10 7 19 23 15
191 - - - 10 - - - 18 22 14
207 - - - 10 - - - 17 20 14
218 - - - 9 - - - - - - 19 - - -
232 - - - 9 - - - - - - 17 - - -
Pressure-Temperature Ratings for ASTM B61 and B62 Cast Bronze Valves(in accordance with ASME B16.24)
SERVICETEMPERATURE
WORKING PRESSURE
Class 150 Class 300
ASTM B 62C83600
ASTM B 61C92200
ASTM B 62C83600
ASTM B 61C92200
�F �C psig bar psig bar psig bar psig bar
−20 to 150 -29 to 66 225 16 225 16 500 34 500 34
175 79 220 15 220 15 480 33 490 34
200 93 210 14 215 15 465 32 475 33
225 107 205 14 210 14 445 31 465 32
250 121 195 13 205 14 425 29 450 31
275 135 190 13 200 14 410 28 440 30
300 149 180 12 195 13 390 27 425 29
350 177 165 11 180 12 350 24 400 28
400 204 - - - - - - 170 12 - - - - - - 375 26
406 207 150 10 - - - - - - - - - - - - - - - - - -
450 232 135 (1) 9 160 11 280 (1) 19 350 24
500 260 - - - - - - 150 10 - - - - - - 325 22
550 288 - - - - - - 140 10 - - - - - - 300 211. Some codes (e.g., ASME Boiler and Pressure Vessel Code, Section 1; ASME B31.1; ASME B31.5) limit the ratingtemperature of the indicated material to 406�F.
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Face−to Face Dimensions for Flanged Globe−Style Control ValvesClasses 125, 150, 250, 300 and 600
(Dimensions in accordance with ISA S75.03)
VALVESIZE
PRESSURE RATINGS AND END CONNECTIONS
CL 125 FF (CI)CL 150 RF (STL)
CL 150 RTJ(STL)
CL 250 RF (CI)CL 300 RF
(STL)
CL 300 RTJ(STL)
CL 600 RF(STL)
CL 600 RTJ(STL)
DN NPS mm in mm in mm in mm in mm in mm in
15 1/2 184 7.25 197 7.75 190 7.50 202 7.94 203 8.00 203 8.00
20 3/4 184 7.25 197 7.75 194 7.62 206 8.12 206 8.12 206 8.12
25 1 184 7.25 197 7.75 197 7.75 210 8.25 210 8.25 210 8.25
40 1−1/2 222 8.75 235 9.25 235 9.25 248 9.75 251 9.88 251 9.88
50 2 254 10.00 267 10.50 267 10.50 282 11.12 286 11.25 284 11.37
65 2−1/2 276 10.88 289 11.38 292 11.50 308 12.12 311 12.25 314 12.37
80 3 298 11.75 311 12.25 318 12.50 333 13.12 337 13.25 340 13.37
100 4 352 13.88 365 14.38 368 14.50 384 15.12 394 15.50 397 15.62
150 6 451 17.75 464 18.25 473 18.62 489 19.24 508 20.00 511 20.12
200 8 543 21.38 556 21.88 568 22.38 584 23.00 610 24.00 613 24.12
250 10 673 26.50 686 27.00 708 27.88 724 28.50 752 29.62 755 29.74
300 12 737 29.00 749 29.50 775 30.50 790 31.12 819 32.25 822 32.37
350 14 889 35.00 902 35.50 927 36.50 943 37.12 972 38.25 475 38.37
400 16 1016 40.00 1029 40.50 1057 41.62 1073 42.24 1108 43.62 1111 43.74Abbreviations used above: FF − Flat Face; RF − Raised Face; RTJ − Ring Type Joint; CI − Cast Iron; STL − Steel
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Face−to−Face Dimensions for Flanged Globe−Style Control ValvesClasses 900, 1500 and 2500
(Dimensions in accordance with ISA S75.16)
VALVE SIZECL 900 CL 1500 CL 2500
mm in mm in mm in
DN NPS Short Long Short Long Short Long Short Long Short Long Short Long
15 1/2 273 292 10.75 11.50 273 292 10.75 11.50 308 318 12.12 12.50
20 3/4 273 292 10.75 11.50 273 292 10.75 11.50 308 318 12.12 12.50
25 1 273 292 10.75 11.50 273 292 10.75 11.50 308 318 12.12 12.50
40 1−1/2 311 333 12.25 13.12 311 333 12.25 13.12 359 381 14.12 15.00
50 2 340 375 13.38 14.75 340 375 13.38 14.75 − − − 400 − − − 16.25
65 2−1/2 − − − 410 - - - 16.12 − − − 410 − − − 16.12 − − − 441 − − − 17.38
80 3 387 441 15.25 17.38 406 460 16.00 18.12 498 660 19.62 26.00
100 4 464 511 18.25 20.12 483 530 19.00 20.87 575 737 22.62 29.00
150 6 600 714 21.87 28.12 692 768 24.00 30.25 819 864 32.25 34.00
200 8 781 914 30.75 36.00 838 972 33.00 38.25 − − − 1022 − − − 40.25
250 10 864 991 34.00 39.00 991 1067 39.00 42.00 1270 1372 50.00 54.00
300 12 1016 1130 40.00 44.50 1130 1219 44.50 48.00 1321 1575 52.00 62.00
350 14 − − − 1257 − − − 49.50 − − − 1257 − − − 49.50 − − − − − − − − − − − −
400 16 − − − 1422 − − − 56.00 − − − 1422 − − − 56.00 − − − − − − − − − − − −
450 18 − − − 1727 − − − 68.00 − − − 1727 − − − 68.00 − − − − − − − − − − − −
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Face−to−Face Dimensions for Buttweld−End Globe−Style Control ValvesClasses 150, 300, 600, 900, 1500 and 2500
(Dimensions in accordance with ISA S75.15)
VALVE SIZECL 150, 300 and 600 CL 900 and 1500 CL 2500
mm in mm in mm in
DN NPS Short Long Short Long Short Long Short Long Short Long Short Long
15 1/2 187 203 7.38 8.00 194 279 7.62 11.00 216 318 8.50 12.50
20 3/4 187 206 7.38 8.25 194 279 7.62 11.00 216 318 8.50 12.50
25 1 187 210 7.38 8.25 197 279 7.75 11.00 216 318 8.50 12.50
40 1−1/2 222 251 8.75 9.88 235 330 9.25 13.00 260 359 10.25 14.12
50 2 254 286 10.00 11.25 292 375 11.50 14.75 318 400 12.50 15.75
65 2−1/2 292 311 11.50 12.25 292 375 11.50 14.75 318 400 12.50 15.75
80 3 318 337 12.50 13.25 318 460 12.50 18.12 381 498 15.00 19.62
100 4 368 394 14.50 15.50 368 530 14.50 20.88 406 575 16.00 22.62
150 6 451 508 17.75 20.00 508 768 24.00 30.25 610 819 24.00 32.25
200 8 543 610 21.38 24.00 610 832 24.00 32.75 762 1029 30.00 40.25
250 10 673 752 26.50 29.62 762 991 30.00 39.00 1016 1270 40.00 50.00
300 12 737 819 29.00 32.35 914 1130 36.00 44.50 1118 1422 44.00 56.00
350 14 851 1029 33.50 40.50 − − − 1257 − − − 49.50 − − − 1803 − − − 71.00
400 16 1016 1108 40.00 43.62 − − − 1422 − − − 56.00 − − − − − − − − − − − −
450 18 1143 − − − 45.00 − − − − − − 1727 − − − 68.00 − − − − − − − − − − − −
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Face−to−Face Dimensions for Socket Weld−End Globe−Style Control ValvesClasses 150, 300, 600, 900, 1500 and 2500
(Dimensions in accordance with ISA S75.12)
VALVE SIZECL 150, 300 and 600 CL 900 and 1500 CL 2500
mm in mm in mm in
DN NPS Short Long Short Long Short Long Short Long Short long Short Long
15 1/2 170 206 6.69 8.12 178 279 7.00 11.00 216 318 8.50 12.50
20 3/4 170 210 6.69 8.25 178 279 7.00 11.00 216 318 8.50 12.50
25 1 197 210 7.75 8.25 178 279 7.00 11.00 216 318 8.50 12.50
40 1−1/2 235 251 9.25 9.88 235 330 9.25 13.00 260 381 10.25 15.00
50 2 267 286 10.50 11.25 292 375 11.50 14.75 324 400 12.75 15.75
65 2−1/2 292 311 11.50 12.25 292 − − − 11.50 − − − 324 − − − 12.75 − − −
80 3 318 337 12.50 13.25 318 533 12.50 21.00 381 660 15.00 26.00
100 4 368 394 14.50 15.50 368 530 14.50 20.88 406 737 16.00 29.00
Chapter 5. Control Valve Selection
90
Face-to-Face Dimensions for Screwed-End Globe-Style Control ValvesClasses 150, 300 and 600
(Dimensions in accordance with ISA S75.12)
VALVE SIZECLASSES 150, 300 AND 600
mm in
DN NPS Short Long Short Long
15 1/2 165 206 6.50 8.12
20 3/4 165 210 6.50 8.25
25 1 197 210 7.75 8.25
40 1-1/2 235 251 9.25 9.88
50 2 267 286 10.50 11.25
65 2-1/2 292 311 11.50 12.26
Face-to-Centerline Dimensions for Raised FaceGlobe-Style Angle Control Valves
Classes 150, 300 and 600(Dimensions in accordance with ISA S75.22)
VALVE SIZE CLASS 150 CLASS 300 CLASS 600
DN NPS mm in mm in mm in
25 1 92 3.62 99 3.88 105 4.12
40 1-1/2 111 4.37 117 4.62 125 4.94
50 2 127 5.00 133 5.25 143 5.62
80 3 149 5.88 159 6.25 168 6.62
100 4 176 6.94 184 7.25 197 7.75
150 6 226 8.88 236 9.31 254 10.00
200 8 272 10.69 284 11.19 305 12.00
Face-to-Face Dimensions for Separable Flanged Globe-Style Control ValvesClasses 150, 300 and 600
(Dimensions in accordance with ISA S75.20)
VALVE SIZE CLASSES 150, 300 AND 600
DN NPS mm in
25 1 216 8.50
40 1-1/2 241 9.50
50 2 292 11.50
80 3 356 14.00
100 4 432 17.00
Chapter 5. Control Valve Selection
91
Face-to-Face Dimensions for Flangeless, Partial-Ball Control ValvesClasses 150, 300 and 600
(Dimensions in accordance with ISA S75.04)
VALVE SIZE CLASSES 150, 300 AND 600
DN NPS mm in
20 3/4 76 3.00
25 1 102 4.00
40 1-1/2 114 4.50
50 2 124 4.88
80 3 165 6.50
100 4 194 7.62
150 6 229 9.00
200 8 243 9.56
250 10 297 11.69
300 12 338 13.31
350 14 400 15.75
400 16 400 15.75
450 18 457 18.00
500 20 508 20.00
600 24 610 24.00
Face-to-Face Dimensions for Single Flange (Lug-Type) andFlangeless (Wafer-Type) Butterfly Control Valves
(Dimensions in accordance with MSS−SP−67)
VALVE SIZE DIMENSIONS FOR NARROWVALVE BODY INSTALLED (1)(2)
NPS DN in mm
1-1/2 40 1.31 33.3
2 50 1.69 42.9
2-1/2 65 1.81 46.0
3 80 1.81 46.0
4 100 2.06 52.3
6 150 2.19 55.6
8 200 2.38 60.5
10 250 2.69 68.3
12 300 3.06 77.7
14 350 3.06 77.7
16 400 3.12 79.2
18 450 4.00 101.6
20 500 4.38 111.21. Bodies compatible with Class 125 cast iron flanges or Class 150 steel flanges.2. This is the dimension of the valve face-to-face after it is installed in the pipeline. It does not include the thickness ofgaskets if separate gaskets are used. It does include the thickness of gaskets or seals that are an integral part of thevalve; however, this dimension is established with the gaskets or seals compressed.
Chapter 5. Control Valve Selection
92
Face-to-Face Dimensions for High Pressure Butterfly Valves with Offset DesignClasses 150, 300 and 600
(Dimensions in accordance with MSS SP−68)
VALVE SIZE CLASS 150 CLASS 300 CLASS 600
NPS DN in mm in mm in mm
3 80 1.88 48 1.88 48 2.12 54
4 100 2.12 54 2.12 54 2.50 64
6 150 2.25 57 2.31 59 3.06 78
8 200 2.50 63 2.88 73 4.00 102
10 250 2.81 71 3.25 83 4.62 117
12 300 3.19 81 3.62 92 5.50 140
14 350 3.62 92 4.62 117 6.12 155
16 400 4.00 101 5.25 133 7.00 178
18 450 4.50 114 5.88 149 7.88 200
20 500 5.00 127 6.25 159 8.50 216
24 600 6.06 154 7.12 181 9.13 232
Wear & Galling Resistance Chart Of Material Combinations
304
316
Bro
nze
Inco
nel
600
, 625
Mo
nel
400
Has
tello
y B
2
Has
tello
y C
276
Tit
aniu
m
Nic
kel
Allo
y 20
Typ
e 41
6 H
ard
Typ
e 44
0 H
ard
17−4
PH
Allo
y 6
(Co
Cr−
A)
Cr
pla
te
Al B
ron
ze
304 SST P P F P P P P P P P F F F F F F F
316 SST P P F P P P P P P P F F F F F F F
Bronze F F S F F F F F F F S S S S S S F
Inconel 600, 625 P P F P P P P P P P F F F F F F F
Monel 400 P P F P P P P P P P F F F F S S F
Hastelloy B2 P P F P P P P P P P F F F S S S F
Hastelloy C276 P P F P P P P P P P F F F S S S F
Titanium P P F P P P P P P P F F F S F F F
Nickel P P F P P P P P P P F F F F F F F
Alloy 20 P P F P P P P P P P F F F S F F F
Type 416 Hard F F S F F F F F F F S S S S S S S
Type 440 Hard F F S F F F F F F F S S S S S S S
17-4 PH F F S F F F F F F F S S F S S S S
Alloy 6(CoCr−A) F F S F F S S S F S S S S S S S S
ENC F F S F S S S F F F S S S S F S S
Cr Plate F F S F S S S F F F S S S S S F S
Al Bronze F F F F F F F F F F S S S S S S FMonel and Inconel are Trademarks of Special Metals Corp.Hastelloy is a Trademark of Haynes InternationalS—SatisfactoryF—FairP—Poor
Chapter 5. Control Valve Selection
93
Control Valve Seat Leakage Classifications(In accordance with ANSI/FCI 70−2 and IEC 60534-4)
LeakageClass
Designation
MaximumLeakage
AllowableTest Medium Test Pressures
TestingProceduresRequired forEstablishing
Rating
I - - - - - - - - -No test requiredprovided user andsupplier so agree.
II 0.5% of ratedcapacity
Air or water at10−52�C(50−125�F)
3-4 bar (45−60psig) or max.operatingdifferential,whichever islower.
Pressure applied tovalve inlet, withoutlet open toatmosphere orconnected to a lowhead lossmeasuring device,full normal closingthrust provided byactuator.
III 0.1% of ratedcapacity
As above As above As above.
IV 0.01% of ratedcapacity
As above As above As above.
V
0.0005ml perminute of waterper inch of orificediameter per psidifferential(5 X 10−12m3 persecond of waterper mm of orificediameter per bardifferential).
Water at 10−52�C(50−125�F)
Max. servicepressure dropacross valve plug,not to exceedANSI body rating,or lesser pressureby agreement.
Pressure applied tovalve inlet afterfilling entire bodycavity andconnected pipingwith water andstroking valve plugclosed. Use netspecified max.actuator thrust, butno more, even ifavailable duringtest. Allow time forleakage flow tostabilize.
VI
Not to exceedamounts shownin following tablebased on portdiameter.
Air or nitrogen at10−52�C(50−125�F)
3.5 bar (50 psig)or max. rateddifferentialpressure acrossvalve plug,whichever islower.
Pressure applied tovalve inlet. Actuatorshould be adjustedto operatingconditions specifiedwith full normalclosing thrustapplied to valveplug seat. Allowtime for leakageflow to stabilize anduse suitablemeasuring device.
Chapter 5. Control Valve Selection
94
Class VI Maximum Seat Leakage Allowable(In accordance with ANSI/FCI 70−2)
NOMINAL PORT DIAMETER BUBBLES PER MINUTE(1)
in mm ml per minute Bubbles per minute
1 25 0.15 1
1-1/2 38 0.30 2
2 51 0.45 3
2-1/2 64 0.60 4
3 76 0.90 6
4 102 1.70 11
6 152 4.00 27
8 203 6.75 451. Bubbles per minute as tabulated are a suggested alternative based on a suitably calibrated measuring device, inthis case a 1/4 inch (6.3 mm) O.D. x 0.032 inch (0.8 mm) wall tube submerged in water to a depth of from 1/8 to 1/4inch (3 to 6 mm). The tube end shall be cut square and smooth with no chamfers or burrs, and the tube axis shall beperpendicular to the surface of the water. Other apparatus may be constructed and the number of bubbles per minutemay differ from those shown as long as they correctly indicate the flow in ml per minute.
Typical Valve Trim Material Temperature Limits
MATERIAL APPLICATIONLOWER UPPER
�F �C �F �C
304 SST, S30400, CF8 uncoated plugs and seats −450 −268 600 316
316 SST, S31600, CF8M uncoated plugs and seats −450 −268 600 316
317 SST, S31700, CG8M uncoated plugs and seats −450 −268 600 316
416 SST, S41600, 38 HRC min cages, plugs and seats −20 −29 800 427
CA6NM, 32 HRC min cages, plugs and seats −20 −29 900 482
Nitronic 50(1), S20910 high strength condition shafts, stems and pins −325 −198 1100 593
440 SST, S44004 bushings, plugs and seats −20 −29 800 427
17−4 PH, S17400, CB7Cu−1, H1075condition
cages, plugs and seats −80 −62 800 427
Alloy 6, R30006, CoCr−A plugs and seats −325 −198 1500 816
Electroless Nickel Coating trim coating −325 −198 750 400
Hard Chromium Plating trim coating −325 −198 600 316
Hard Chromium Plating on V−balls trim coating −325 −198 800 427
Hard Chromium Coating trim coating −325 −198 1100 593
Monel (2) K500, N05500 uncoated plugs and seats −325 −198 800 427
Monel (2) 400, N04400 uncoated plugs and seats −325 −198 800 427
Hastelloy (3) B2, N10665, N7M uncoated plugs and seats −325 −198 800 427
Hastelloy (3) C276, N10276, CW2M uncoated plugs and seats −325 −198 800 427
Titanium Grades 2, 3, 4, C2, C3, C4 uncoated plugs and seats −75 −59 600 316
Nickel, N02200, CZ100 uncoated plugs and seats −325 −198 600 316
Alloy 20, N08020, CN7M uncoated plugs and seats −325 −198 600 316
NBR, nitrile rubber seats −20 −29 200 93
FKM Fluoroelastomer (Viton®(4)) seats 0 −18 400 204
PTFE, polytetrafluoroethylene seats −450 −268 450 232
PA (nylon) seats −60 −51 200 93
HDPE, high density polyethylene seats −65 −54 185 85
CR, chloroprene (Neoprene(2)) seats −40 −40 180 82
1. Trademark of Armco Steel Corp.2. Monel and Inconel are tradenames of Special Metals Corp.3. Hastelloy is a tradename of Haynes International4. Registered trademark of DuPont Performance Elastomers
Chapter 5. Control Valve Selection
95
Service TemperatureLimitations for ElastomersTemperature ranges indicated in theService Temperature Limitations tablesuggest limits within which the materi-als will function adequately. Tempera-
tures shown are not necessarily inher-ent temperature limits. Dynamicforces imposed on the materials arealso considered. Frequently, tearstrength and other physical propertiesdecrease rapidly as service tempera-ture increases.
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96 Ambient Temperature Corrosion Information This corrosion table is intended to give only a general indication of how various metals will react when in contact with certain fluids. Therecommendations cannot be absolute because concentration, temperature, pressure and other conditions may alter the suitability of aparticular metal. There are also economic considerations that may influence metal selection. Use this table as a guide only. A = normallysuitable; B = minor to moderate effect, proceed with caution; C = unsatisfactory.
Fluid Alum Brass
CastIron
&Steel
416 &440C
17−4SST
304SST
316SST
DuplexSST
254SMO
Alloy20
Alloy400
AlloyC276
AlloyB2
Alloy6
Tita−nium
Zirco−nium
AcetaldehydeAcetic Acid, Air FreeAcetic Acid, AeratedAcetoneAcetylene
ACCBA
ACCAA
CCCAA
ACCAA
ACBAA
ACBAA
AAAAA
AAAAA
AAAAA
AAAAA
AACAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AlcoholsAluminum SulfateAmmoniaAmmonium ChlorideAmmonium Hydroxide
ACACA
ACCCC
ACACA
ACACA
ABACA
AAACA
AAABA
AAAAA
AAAAA
AAAAA
ABABC
AAAAA
AAAAA
AAABA
AAAAA
AAAAB
Ammonium NitrateAmmonium Phosphate (Mono−Basic)Ammonium SulfateAmmonium SulfiteAniline
BB
CCC
CB
CCC
BC
CCC
BB
CCC
AB
BAA
AA
BAA
AA
AAA
AA
AAA
AA
AAA
AA
AAA
CB
ACB
AA
AAA
AA
AAA
AA
AAA
CA
AAA
AA
AAA
AsphaltBeerBenzene (Benzol)Benzoic AcidBoric Acid
AAAAC
AAAAB
ABACC
ABACC
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAB
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
Bromine, DryBromine, WetButaneCalcium ChlorideCalcium Hypochlorite
CCACC
CCACC
CCABC
CCACC
BCACC
BCABC
BCABC
ACAAA
ACAAA
ACAAA
AAAAC
AAAAA
AAAAB
ACAAB
CCAAA
CCAAA
(continued)
Ch
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Ambient Temperature Corrosion Information (continued)This corrosion table is intended to give only a general indication of how various metals will react when in contact with certain fluids. Therecommendations cannot be absolute because concentration, temperature, pressure and other conditions may alter the suitability of aparticular metal. There are also economic considerations that may influence metal selection. Use this table as a guide only. A = normallysuitable; B = minor to moderate effect, proceed with caution; C = unsatisfactory.
Fluid Zirco−nium
Tita−nium
Alloy6
AlloyB2
AlloyC276
Alloy400
Alloy20
254SMO
DuplexSST
316SST
304SST
17−4SST
416 &440C
CastIron
&Steel
BrassAlum
Carbon Dioxide, DryCarbon Dioxide, WetCarbon DisulfideCarbonic AcidCarbon Tetrachloride
AACAA
ABCBA
ACACB
ACBCB
AABAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AABAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
Caustic Potash(see Potassium Hydroxide)
Caustic Soda(see Sodium Hydroxide)
Chlorine, DryChlorine, WetChromic Acid
CCC
CCC
ACC
CCC
BCC
BCC
BCC
ACB
ACA
ACC
ABC
ABA
ABB
ACC
CAA
AAA
Citric AcidCoke Oven AcidCopper SulfateCottonseed OilCreosote
BCCAC
CBCAC
CACAA
CACAA
BACAA
BACAA
AABAA
AAAAA
AAAAA
AAAAA
ABCAA
AAAAA
AAAAA
AACAA
AAAAA
AAAAA
DowthermEthaneEtherEthyl ChlorideEthylene
AAACA
AAABA
AABCA
AAACA
AAABA
AAABA
AAABA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
(continued)
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98 Ambient Temperature Corrosion Information (continued)This corrosion table is intended to give only a general indication of how various metals will react when in contact with certain fluids. Therecommendations cannot be absolute because concentration, temperature, pressure and other conditions may alter the suitability of aparticular metal. There are also economic considerations that may influence metal selection. Use this table as a guide only. A = normallysuitable; B = minor to moderate effect, proceed with caution; C = unsatisfactory.
Fluid Zirco−nium
Tita−nium
Alloy6
AlloyB2
AlloyC276
Alloy400
Alloy20
254SMO
DuplexSST
316SST
304SST
17−4SST
416 &440C
CastIron
&Steel
BrassAlum
Ethylene GlycolFerric ChlorideFluorine, DryFluorine, WetFormaldehyde
ACBCA
ACBCA
ACACB
ACCCA
ACBCA
ACBCA
ACBCA
ACACA
ABACA
ACACA
ACABA
AAABA
ACABA
ACACA
AACCA
AACCA
Formic AcidFreon, WetFreon, DryFurfuralGasoline, Refined
BCAAA
CCAAA
CBBAA
CCABA
CBAAA
CBAAA
BAAAA
AAAAA
AAAAA
AAAAA
CAAAA
AAAAA
BAAAA
BAAAA
CAAAA
AAAAA
GlucoseHydrochloric Acid (Aerated)Hydrochloric Acid (Air Free)Hydrofluoric Acid(Aerated)Hydrofluoric Acid (Air Free)
ACCCC
ACCCC
ACCCC
ACCCC
ACCCC
ACCCC
ACCCC
CCCCC
ACCCC
ACCCC
ACCBA
ABBBB
AAABB
ACCCC
ACCCC
AAACC
HydrogenHydrogen PeroxideHydrogen SulfideIodineMagnesium Hydroxide
AACCB
ACCCB
ACCCA
CCCCA
BBCAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
ACACA
AAAAA
ACAAA
AAAAA
CAACA
AAABA
MercuryMethanolMethyl Ethyl KetoneMilkNatural Gas
CAAAA
CAAAA
AAACA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
BAAAA
AAAAA
AAAAA
AAAAA
CAAAA
AAAAA
(continued)
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Ambient Temperature Corrosion Information (continued)This corrosion table is intended to give only a general indication of how various metals will react when in contact with certain fluids. Therecommendations cannot be absolute because concentration, temperature, pressure and other conditions may alter the suitability of aparticular metal. There are also economic considerations that may influence metal selection. Use this table as a guide only. A = normallysuitable; B = minor to moderate effect, proceed with caution; C = unsatisfactory.
Fluid Zirco−nium
Tita−nium
Alloy6
AlloyB2
AlloyC276
Alloy400
Alloy20
254SMO
DuplexSST
316SST
304SST
17−4SST
416 &440C
CastIron
&Steel
BrassAlum
Nitric AcidOleic AcidOxalic AcidOxygenPetroleum Oils, Refined
CCCCA
CCCAA
CCCCA
CBCCA
ABBBA
ABBBA
AABBA
AAABA
AAABA
AAABA
CABAA
BAABA
CAABA
CABBA
AACCA
AAACA
Phosphoric Acid (Aerated)Phosphoric Acid (Air Free)Picric AcidPotash/Potassium Carbonate
CCCC
CCCC
CCCB
CCCB
BBBA
ABBA
ABAA
AAAA
AAAA
AAAA
CBCA
AAAA
AAAA
ABAA
CCAA
AAAA
Potassium ChloridePotassium HydroxidePropaneRosinSilver Nitrate
CCAAC
CCAAC
BBABC
CBAAC
CAAAB
BAAAA
BAAAA
AAAAA
AAAAA
AAAAA
AAAAC
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
Soda Ash(see Sodium Carbonate)
Sodium AcetateSodium CarbonateSodium ChlorideSodium Chromate
ACCA
ACAA
AACA
ABCA
AABA
AABA
AABA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
AAAA
Sodium HydroxideSodium HypochloriteSodium ThiosulfateStannous ChlorideSteam
CCCCA
CCCCA
ACCCA
BCCCA
BCBCA
BCBCA
ACABA
ACAAA
ACAAA
ACAAA
ACACA
AAAAA
ABAAA
ACABA
AAAAA
AAAAA
(continued)
Ch
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100 Ambient Temperature Corrosion Information (continued)This corrosion table is intended to give only a general indication of how various metals will react when in contact with certain fluids. Therecommendations cannot be absolute because concentration, temperature, pressure and other conditions may alter the suitability of aparticular metal. There are also economic considerations that may influence metal selection. Use this table as a guide only. A = normallysuitable; B = minor to moderate effect, proceed with caution; C = unsatisfactory.
Fluid Zirco−nium
Tita−nium
Alloy6
AlloyB2
AlloyC276
Alloy400
Alloy20
254SMO
DuplexSST
316SST
304SST
17−4SST
416 &440C
CastIron
&Steel
BrassAlum
Stearic AcidSulfate Liquor (Black)SulfurSulfur Dioxide, DrySulfur Trioxide, Dry
CCACC
BCBCC
BAACC
BCACC
BCACC
ABACC
AAABB
AAAAA
AAAAA
AAAAA
AAACB
AAAAA
AAAAA
BAABB
AAAAA
AAAAA
Sulfuric Acid (Aerated)Sulfuric Acid (Air Free)Sulfurous AcidTarTrichloroethylene
CCCAB
CCCAB
CCCAB
CCCAB
CCCAB
CCBAB
CCBAA
AAAAA
AAAAA
AAAAA
CBCAA
AAAAA
CAAAA
BBBAA
CCAAA
AAAAA
TurpentineVinegarWater, Boiler feed, Amine TreatedWater, DistilledWater, Sea
ABAAC
ABAAA
BCACC
ACACC
AAAAC
AAAAC
AAAAB
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AAAAA
AACAA
AAAAA
AAAAA
Whiskey and WinesZinc ChlorideZinc Sulfate
ACC
ACC
CCC
CCC
ACA
ACA
ACA
ABA
ABA
ABA
AAA
AAA
AAA
ABA
AAA
AAA
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101
Elastomer Information Selection of a suitable elastomer material for use in control valve applications requires knowledge of the service conditions in which the material will be used, aswell as knowledge of the general properties of the material itself. Service temperature, pressure, rate of flow, type of valve action (throttling or on−off), andchemical composition of the fluid should all be known. Usage ratings listed below (Excellent, VG=Very Good, Good, Fair, Poor, VP=Very Poor, ) should be usedas a guide only. Specific compounds within any one material may vary, which could change the usage ratings.
Property
ACM,ANIM(1)
Poly−acrylic
AU,EU (2)Poly−ure−thane
CO,ECOEpi−chloro−hydrin
CRChloro−preneNeo−prene
EPM,EPDM(3)
EthylenePro−pylene
FKM,(1,2)
Fluoro−elast−omerViton(4)
FFKMPer−fluoro−elast−omer
IIRButyl
VMQSilicone
NBRNitrileBuna N
NRNaturalRubber
SBRBuna−SGRS
TFE/PTetra−fluoro−ethylenepro−pylenecopoly−mer
Tensile, psi (MPa)Pure GumReinforced
100(0.7)1800(12)
− − −6500(45)
2000(14)2500(17)
3500(24)3500(24)
− − −2500(17)
− − −2300(16)
− − −3200(22)
3000(21)3000(21)
200−450(1.4−3)1100(8)
600(4)4000(28)
3000(21)4500(31)
400(3)3000(21)
− − −2800(19)
Tear Resistance Fair Excellent Good Good Poor Good − − − Good Poor−Fair Fair Excellent Poor−Fair Good
Abrasion Resistance Good Excellent Fair Excellent Good VG − − − Fair Poor Good Excellent Good Good
Aging: SunlightOxidation
Heat: (Max. Temp.)
ExcellentExcellent350�F(117�C)
ExcellentExcellent200�F(93�C)
GoodGood275�F(135�C)
ExcellentGood200�F(93�C)
ExcellentGood350�F(117�C)
ExcellentExcellent400�F(204�C)
ExcellentExcellent550�F(288�C)
ExcellentGood200�F(93�C)
GoodVG450�F(232�C)
PoorFair250�F(121�C)
PoorGood200�F(93�C)
PoorFair200�F(93�C)
− − −Excellent400�F(204�C)
Flex Cracking Resistance
Good Excellent − − − Excellent − − − − − − − − − Excellent Fair Good Excellent Good − − −
Compression Set Resistance
Good Good Fair Excellent Fair Poor − − − Fair Good VG Good Good Good
Solvent Resistance:Aliphatic HydrocarbonAromatic HydrocarbonOxygenated SolventHalogenated Solvent
GoodPoorPoorPoor
VGFairPoor− − −
ExcellentGood− − −− − −
FairPoorFairVP
PoorFair− − −Poor
ExcellentVGGood− − −
ExcellentExcellentExcellentExcellent
PoorVPGoodPoor
PoorVPPoorVP
GoodFairPoorVP
VPVPGoodVP
VPVPGoodVP
GoodFairPoorPoor/Good
(continued)
Ch
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102 Elastomer Information (continued)Selection of a suitable elastomer material for use in control valve applications requires knowledge of the service conditions in which the material will be used, aswell as knowledge of the general properties of the material itself. Service temperature, pressure, rate of flow, type of valve action (throttling or on−off), andchemical composition of the fluid should all be known. Usage ratings listed below (Excellent, VG=Very Good, Good, Fair, Poor, VP=Very Poor, ) should be usedas a guide only. Specific compounds within any one material may vary, which could change the usage ratings.
Property
TFE/PTetra−fluoro−ethylenepro−pylenecopoly−mer
SBRBuna−SGRS
NRNaturalRubber
NBRNitrileBuna N
VMQSilicone
IIRButyl
FFKMPer−fluoro−elast−omer
FKM,(1,2)
Fluoro−elast−omerViton(4)
EPM,EPDM(3)
EthylenePro−pylene
CRChloro−preneNeo−prene
CO,ECOEpi−chloro−hydrin
AU,EU (2)Poly−ure−thane
ACM,ANIM(1)
Poly−acrylic
Oil Resistance:Low Aniline Mineral OilHigh Aniline Mineral OilSynthetic LubricantsOrganic Phosphates
ExcellentExcellentFairPoor
− − −− − −− − −Poor
− − −− − −ExcellentExcellent
FairGoodVPVP
PoorPoorPoorVG
ExcellentExcellent- - -Poor
ExcellentExcellentExcellentExcellent
VPVPPoorGood
PoorGoodFairPoor
ExcellentExcellentFairVP
VPVPVPVP
VPVPVPVP
ExcellentFairExcellentGood
Gasoline Resistance:AromaticNon−Aromatic
FairPoor
FairGood
ExcellentExcellent
PoorGood
FairPoor
GoodVG
ExcellentExcellent
VPVP
PoorGood
GoodExcellent
VPVP
VPVP
PoorFair
Acid Resistance:Dilute (Under 10%)^Concentrated(5)
PoorPoor
FairPoor
GoodGood
FairFair
VGGood
ExcellentVG
ExcellentExcellent
GoodFair
FairPoor
GoodPoor
GoodFair
GoodPoor
ExcellentGood
Low TemperatureFlexibility (Max)
−10�F(−23�C)
−40�F(−40�C)
−40�F(−40�C)
−40�F(−40�C)
−50�F(−45�C)
−30�F(−34�C)
0�F(−18�C)
−40�F(−40�C)
−100�F(−73�C)
−40�F(−40�C)
−65�F(−54�C)
−50�F(−46�C)
0�F(−18�C)
Permeability to Gases Good Good Excellent VG Good Good Fair VG Fair Fair Fair Fair − − −
Water Resistance Fair Fair Fair Fair VG Excellent Excellent VG Fair VG Good VG Excellent
Alkali Resistance:Dilute (Under 10 %)Concentrated
PoorPoor
FairPoor
ExcellentExcellent
GoodGood
ExcellentGood
ExcellentVG
ExcellentExcellent
VGVG
FairPoor
GoodFair
GoodFair
GoodFair
ExcellentGood
(continued)
Ch
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103
Elastomer Information (continued)Selection of a suitable elastomer material for use in control valve applications requires knowledge of the service conditions in which the material will be used, aswell as knowledge of the general properties of the material itself. Service temperature, pressure, rate of flow, type of valve action (throttling or on−off), andchemical composition of the fluid should all be known. Usage ratings listed below (Excellent, VG=Very Good, Good, Fair, Poor, VP=Very Poor, ) should be usedas a guide only. Specific compounds within any one material may vary, which could change the usage ratings.
Property
TFE/PTetra−fluoro−ethylenepro−pylenecopoly−mer
SBRBuna−SGRS
NRNaturalRubber
NBRNitrileBuna N
VMQSilicone
IIRButyl
FFKMPer−fluoro−elast−omer
FKM,(1,2)
Fluoro−elast−omerViton(4)
EPM,EPDM(3)
EthylenePro−pylene
CRChloro−preneNeo−prene
CO,ECOEpi−chloro−hydrin
AU,EU (2)Poly−ure−thane
ACM,ANIM(1)
Poly−acrylic
Resilience VP Fair Fair VG VG Good − − − VG Good Fair VG Fair − − −
Elongation (Max) 200% 625% 400% 500% 500% 425% 142% 700% 300% 500% 700% 500% 400%
1. Do not use with steam.2. Do not use with ammonia.3. Do not use with petroleum base fluids. Use with ester Base (non−flammable) hydraulic oils and low pressure steam applications to 300�F (149�C).4. Registered trademark of DuPont Performance Elastomers.5. Except Nitric and Sulfuric.
Ch
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104 Fluid Compatibility This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information should be used as a guide only. Anelastomer which is compatible with a fluid may not be suitable over the entire range of its temperature capability. In general, chemical compatibility decreaseswith an increase in service temperature.KEY: A+=Best Possible Selection A=Generally Compatible B=Marginally Compatible C=Not Recommended −=no dataNOTE: These recommendations are to be used as a general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode ofoperation must be considered when selecting an elastomer.
FLUID
ELASTOMER RATINGS FOR COMPATIBILITY WITH FLUID
ACM,ANMPoly−acrylic
AU, EUPoly−urethane
CO, ECOEpichloro−hydrin
CRChloro−preneNeoprene(1)
EPM,EPDMEthylenePropylene
FKMFluoro−elastomerViton(1)
FFKMPerfluoro−elastomer
IIRButyl
VMQSilicone
NBRNitrileBuna N
NRNaturalRubber
TFE/PTetra−fluoroethylene−propylenecopolymer
Acetic Acid (30%)AcetoneAir, Ambient
CCA
CCA
CC−
CCA
A+AA
CCA
A+AA
AAA
ACA
BCA
BCB
CCA
Air, Hot (200�F, 93�C)Air, Hot (400�F, 204�C)Alcohol, Ethyl
BCC
BCC
−−−
CCA
ACA
AAC
AAA
ACA
AAA
ACA
BCA
AAA
Alcohol, MethylAmmonia, Anhydrous, LiquidAmmonia, Gas (Hot)
CCC
CCC
B−−
A+A+B
AAB
CCC
AAA
AAB
ABA
ABC
ACC
AA
A+
Beer (Beverage)BenzeneBlack Liquor
CCC
CCC
AC−
ACB
ACB
AA
A+
AAA
ACC
ACC
ACB
ACB
ACA
Blast Furnace GasBrine (Calcium Chloride)Butadiene Gas
CAC
CAC
−AC
CAC
CAC
A+A
A+
AAA
CAC
AAC
CAC
CAC
AA−
Butane GasButane, LiquidCarbon Tetrachloride
AAC
CCC
AAB
ABC
CCC
AA
A+
AAA
CCC
CCC
A+AC
CCC
BCC
(continued)
Ch
apter 5. C
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105
Fluid Compatibility (continued)This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information should be used as a guide only. Anelastomer which is compatible with a fluid may not be suitable over the entire range of its temperature capability. In general, chemical compatibility decreaseswith an increase in service temperature.KEY: A+=Best Possible Selection A=Generally Compatible B=Marginally Compatible C=Not Recommended −=no dataNOTE: These recommendations are to be used as a general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode ofoperation must be considered when selecting an elastomer.
FLUID
ELASTOMER RATINGS FOR COMPATIBILITY WITH FLUID
FLUID
TFE/PTetra−fluoroethylene−propylenecopolymer
NRNaturalRubber
NBRNitrileBuna N
VMQSilicone
IIRButyl
FFKMPerfluoro−elastomer
FKMFluoro−elastomerViton(1)
EPM,EPDMEthylenePropylene
CRChloro−preneNeoprene(1)
CO, ECOEpichloro−hydrin
AU, EUPoly−urethane
ACM,ANMPoly−acrylic
Chlorine, DryChlorine, WetCoke Oven Gas
CCC
CCC
BB−
CCC
CCC
A+A+A+
AAA
CCC
CCB
CCC
CCC
CBA
Dowtherm A(2)
Ethyl AcetateEthylene Glycol
CCC
CCB
CCA
CCA
CB
A+
A+CA
AAA
CBA
CBA
CCA
CCA
BCA
Freon 11(1)
Freon 12(1)
Freon 22(1)
ABB
CAC
−AA
CA+A+
CBA
B+BC
BBA
CBA
CCC
BAC
CBA
CCC
Freon 114(1)
Freon Replacements(1)
(See Suva)(1)
GasolineHydrogen Gas
−
CB
A
BA
A
A−
A
CA
A
CA
A
AA
B
AA
A
CA
C
CC
A
A+A
A
CB
C
CA
Hydrogen Sulfide (Dry)Hydrogen Sulfide (Wet)Jet Fuel (JP−4)
CCB
BCB
BBA
AAC
A+A+C
CCA
AAA
AAC
CCC
ACA
ACC
AAB
(continued)
Ch
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106 Fluid Compatibility (continued)This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information should be used as a guide only. Anelastomer which is compatible with a fluid may not be suitable over the entire range of its temperature capability. In general, chemical compatibility decreaseswith an increase in service temperature.KEY: A+=Best Possible Selection A=Generally Compatible B=Marginally Compatible C=Not Recommended −=no dataNOTE: These recommendations are to be used as a general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode ofoperation must be considered when selecting an elastomer.
FLUID
ELASTOMER RATINGS FOR COMPATIBILITY WITH FLUID
FLUID
TFE/PTetra−fluoroethylene−propylenecopolymer
NRNaturalRubber
NBRNitrileBuna N
VMQSilicone
IIRButyl
FFKMPerfluoro−elastomer
FKMFluoro−elastomerViton(1)
EPM,EPDMEthylenePropylene
CRChloro−preneNeoprene(1)
CO, ECOEpichloro−hydrin
AU, EUPoly−urethane
ACM,ANMPoly−acrylic
Methylene ChlorideMilkNaphthalene
CC−
CCB
−−−
CAC
CAC
B+A
A+
A+AA
CAC
CAC
CA+C
CAC
BAB
Natural GasNatural Gas +H2S (Sour Gas)Natural Gas, Sour + Ammonia
BC
C
BB
C
AA
−
AA+
B+
CC
C
AC
C
AA
A
CC
C
CC
C
A+B
B
BC
C
AA
A+
Nitric Acid (10%)Nitric Acid (50−100%)
CC
CC
CC
CC
BC
A+A+
AA
AA
CC
CC
CC
AB
Nitric Acid VaporNitrogenOil (Fuel)
CAB
CAC
CAA
BAB
BAC
AAA
AAA
BAC
CAC
CA
A+
CAC
AAA
OzonePaper StockPropane
B−A
ACB
A−A
BBA
ABC
AAA
AAA
BBC
ACC
CB
A+
CCC
A−A
Sea WaterSea Water + Sulfuric AcidSoap Solutions
CCC
BBC
−−A
BBA
ABA
AAA
AAA
ABA
ACA
ACA
BCB
AAA
(continued)
Ch
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107
Fluid Compatibility (continued)This table rates and compares the compatibility of elastomer material with specific fluids. Note that this information should be used as a guide only. Anelastomer which is compatible with a fluid may not be suitable over the entire range of its temperature capability. In general, chemical compatibility decreaseswith an increase in service temperature.KEY: A+=Best Possible Selection A=Generally Compatible B=Marginally Compatible C=Not Recommended −=no dataNOTE: These recommendations are to be used as a general guide only. Full details regarding pressure, temperature, chemical considerations, and the mode ofoperation must be considered when selecting an elastomer.
FLUID
ELASTOMER RATINGS FOR COMPATIBILITY WITH FLUID
FLUID
TFE/PTetra−fluoroethylene−propylenecopolymer
NRNaturalRubber
NBRNitrileBuna N
VMQSilicone
IIRButyl
FFKMPerfluoro−elastomer
FKMFluoro−elastomerViton(1)
EPM,EPDMEthylenePropylene
CRChloro−preneNeoprene(1)
CO, ECOEpichloro−hydrin
AU, EUPoly−urethane
ACM,ANMPoly−acrylic
SteamSulfer Dioxide (Dry)Sulfur Dioxide (Wet)Sulfuric Acid (to 50%)
CCCB
C−BC
C−−B
CCBC
B+A+A+B
C−CA+
A−AA
BBAC
CBBC
CCCC
CBCC
A+−BA
Sulfuric Acid (50−100%)Suva HCFC−123(1)
Suva HFC134a(1)
C−−
CC−
C−−
CA+B
CA+A
A+BC
A−−
CA+B
CBB
CCA+
CCB
A
−
Water (Ambient)Water (200�F, 93�C)
CC
CC
BB
AC
AA+
AB
AA
AB
AA
AC
AA
A−
Water (300�F, 149�C)Water (De−ionized)Water, White
CCC
CAB
−−−
CAB
B+AA
CAA
AAA
BAA
CAB
CAB
CAB
−A−
1. Registered trademark of DuPont Performance Elastomers.2. Trademark of Dow Chemical Co.
Chapter 5. Control Valve Selection
108
Service Temperature Limits for Non−Metallic MaterialsASTM Designations and
TradenamesGeneric Description Temperature Range
CR Chloroprene −40 to 180�F, −40 to 82�C
EPDM Ethylene propylene terpolymer −40 to 275�F, −40 to 135�C
FFKM, Kalrez(1),Chemraz(2) Perfluoroelastomer 0 to 500�F, −18 to 260�C
FKM, Viton(1) Fluoroelastomer 0 to 400�F, −18 to 204�C
FVMQ Fluorosilicone −100 to 300�F, −73 to 149�C
NBR Nitrile −65 to 180�F, −54 to 82�C
NR Natural rubber −20 to 200�F, −29 to 93�C
PUR Polyurethane −20 to 200�F, −29 to 93�C
VMQ Silicone −80 to 450�F, −62 to 232�C
PEEK Polyetheretherketone −100 to 480�F, −73 to 250�C
PTFE Polytetrafluoroethylene −100 to 400�F, −73 to 204�C
PTFE, Carbon Filled Polytetrafluoroethylene,Carbon Filled
−100 to 450�F, −73 to 232�C
PTFE, Glass Filled Polytetrafluoroethylene,Carbon Filled
−100 to 450�F, −73 to 232�C
TCM Plus(3) Mineral and MoS2 filled PTFE −100 to 450�F, −73 to 232�C
TCM Ultra(3) PEEK and MoS2 filled PTFE −100 to 500�F, −73 to 260�C
Composition Gasket −60 to 300�F, −51 to 150�C
Flexible Graphite, Grafoil(4) −300 to 1000�F, −185 to 540�C1. Registered trademark of DuPont Performance Elastomers.2. Trademark of Greene, Tweed & Co.3. Trademark of Fisher Controls International LLC4. Trademark of Union Carbide
Control Valve FlowCharacteristicsThe flow characteristic of a controlvalve is the relationship between theflow rate through the valve and thevalve travel as the travel is variedfrom 0 to 100%. Inherent flow charac-teristic refers to the characteristic ob-served with a constant pressure dropacross the valve. Installed flow char-acteristic means the one obtained inservice where the pressure drop var-ies with flow and other changes in thesystem.
Characterizing control valves providesfor a relatively uniform control loopstability over the expected range ofsystem operating conditions. To es-tablish the flow characteristic neededto match a given system requires adynamic analysis of the control loop.Analyses of the more common pro-cesses have been performed, howev-
er, so some useful guidelines for theselection of the proper flow character-istic can be established. Those guide-lines will be discussed after a brieflook at the flow characteristics in usetoday.
Flow CharacteristicsFigure 5-1 illustrates typical flow char-acteristic curves. The quick−openingflow characteristic provides for maxi-mum change in flow rate at low valvetravels with a nearly linear relation-ship. Additional increases in valvetravel give sharply reduced changesin flow rate, and when the valve plugnears the wide open position, thechange in flow rate approaches zero.In a control valve, the quick openingvalve plug is used primarily for on-offservice; but it is also suitable for manyapplications where a linear valve plugwould normally be specified.
Chapter 5. Control Valve Selection
109
Figure 5-1. Inherent ValveCharacteristics
A3449/IL
The linear flow characteristic curveshows that the flow rate is directly pro-portional to the valve travel. This pro-portional relationship produces a char-acteristic with a constant slope so thatwith constant pressure drop, the valvegain will be the same at all flows.(Valve gain is the ratio of an incremen-tal change in valve plug position. Gainis a function of valve size and configu-ration, system operating conditionsand valve plug characteristic.) The lin-ear valve plug is commonly specifiedfor liquid level control and for certainflow control applications requiringconstant gain.
In the equal−percentage flow charac-teristic, equal increments of valvetravel produce equal percentagechanges in the existing flow. The
change in flow rate is always propor-tional to the flow rate just before thechange in valve plug, disk, or ballposition is made. When the valveplug, disk, or ball is near its seat, theflow is small; with a large flow, thechange in flow rate will be large.Valves with an equal percentage flowcharacteristic are generally used onpressure control applications and onother applications where a large per-centage of the pressure drop is nor-mally absorbed by the system itself,with only a relatively small percentageavailable at the control valve. Valveswith an equal percentage characteris-tic should also be considered wherehighly varying pressure drop condi-tions can be expected.
Selection of Flow Characteristic
Some guidelines will help in the selec-tion of the proper flow characteristic.Remember, however, that there will beoccasional exceptions to most ofthese guidelines, and that a positiverecommendation is possible only bymeans of a complete dynamic analy-sis. Where a linear characteristic isrecommended, a quick opening valveplug could be used, and while thecontroller will have to operate on awider proportional band setting, thesame degree of control accuracy maybe expected. The tables below giveuseful guidelines for selecting valvecharacteristics.
Liquid Level Systems
Control Valve Pressure Drop Best InherentCharacteristic
Constant ∆P Linear
Decreasing ∆P with Increasing Load, ∆P atMaximum Load > 20% of Minimum Load ∆P
Linear
Decreasing ∆P with Increasing Load, ∆P atMaximum Load < 20% of Minimum Load ∆P
Equal Percentage
Increasing ∆P with Increasing Load, ∆P atMaximum Load < 200% of Minimum Load ∆P
Linear
Increasing ∆P with Increasing Load, ∆P atMaximum Load > 200% of Minimum Load ∆P
Quick Opening
Chapter 5. Control Valve Selection
110
Flow Control Processes
FLOW MEASURE−MENT SIGNAL TO
CONTROLLER
LOCATION OFCONTROL VALVEIN RELATION TO
MEASURING ELEMENT
BEST INHERENT CHARACTERISTIC
Wide Range ofFlow Set Point
Small Range of Flow butLarge ∆P Change at Valve
with Increasing Load
ProportionalTo Flow
In Series Linear Equal Percentage
In Bypass(1) Linear Equal Percentage
Proportional ToFlow Squared
In Series Linear Equal Percentage
In Bypass(1) Equal Percentage Equal Percentage1. When control valve closes, flow rate increases in measuring element.
Valve Sizing
Standardization activities for controlvalve sizing can be traced back to theearly 1960’s when a trade association,the Fluids Control Institute, publishedsizing equations for use with bothcompressible and incompressiblefluids. The range of service conditionsthat could be accommodated accu-rately by these equations was quitenarrow, and the standard did notachieve a high degree of acceptance.In 1967, the ISA established a com-mittee to develop and publish stan-dard equations. The efforts of thiscommittee culminated in a valve siz-ing procedure that has achieved thestatus of American National Standard.Later, a committee of the InternationalElectrotechnical Commission (IEC)used the ISA works as a basis to for-mulate international standards for siz-ing control valves. (Some informationin this introductory material has beenextracted from ANSI/ISA S75.01 stan-dard with the permission of the pub-lisher, the ISA.) Except for some slightdifferences in nomenclature and pro-cedures, the ISA and IEC standardshave been harmonized. ANSI/ISAStandard S75.01 is harmonized withIEC Standards 534-2-1 and 534-2-2.(IEC Publications 534-2, SectionsOne and Two for incompressible andcompressible fluids, respectively.)
In the following sections, the nomen-clature and procedures are explained,and sample problems are solved toillustrate their use.
Sizing Valves for LiquidsFollowing is a step-by-step procedurefor the sizing of control valves for liq-uid flow using the IEC procedure.Each of these steps is important andmust be considered during any valvesizing procedure. Steps 3 and 4 con-cern the determination of certain siz-ing factors that may or may not be re-quired in the sizing equationdepending on the service conditionsof the sizing problem. If one, two, orall three of these sizing factors are tobe included in the equation for a par-ticular sizing problem, refer to the ap-propriate factor determination sec-tion(s) located in the text after thesixth step.
1. Specify the variables required tosize the valve as follows:
� Desired design: refer to the ap-propriate valve flow coefficient table inthis chapter.
� Process fluid (water, oil, etc.),and
� Appropriate service conditions
q or w, P1, P2 or ∆P, T1, Gf, Pv, Pc,and υ
The ability to recognize which termsare appropriate for a specific sizingprocedure can only be acquiredthrough experience with differentvalve sizing problems. If any of theabove terms appears to be new or un-familiar, refer to the Abbreviations andTerminology table for a complete defi-nition.
Chapter 5. Control Valve Selection
111
2. Determine the equation constant,N. N is a numerical constant con-tained in each of the flow equations toprovide a means for using differentsystems of units. Values for these var-ious constants and their applicableunits are given in the EquationConstants table.
Use N1, if sizing the valve for a flowrate in volumetric units (gpm or m3/h).
Use N6 if sizing the valve for a flowrate in mass units (lb/h or kg/h).
3. Determine Fp, the piping geometryfactor.
Fp is a correction factor that accountsfor pressure losses due to piping fit-tings such as reducers, elbows, ortees that might be attached directly tothe inlet and outlet connections of thecontrol valve to be sized. If such fit-tings are attached to the valve, the Fpfactor must be considered in the siz-ing procedure. If, however, no fittingsare attached to the valve, Fp has avalue of 1.0 and simply drops out ofthe sizing equation.
Chapter 5. Control Valve Selection
112
Abbreviations and TerminologySymbol Symbol
Cv Valve sizing coefficient P1 Upstream absolute static pressure
d Nominal valve size P2 Downstream absolute staticpressure
D Internal diameter of the piping Pc Absolute thermodynamic criticalpressure
Fd Valve style modifier,dimensionless
Pv Vapor pressure absolute of liquid atinlet temperature
FF Liquid critical pressure ratio factor,dimensionless
∆P Pressure drop (P1-P2) across thevalve
Fk Ratio of specific heats factor,dimensionless
∆Pmax(L) Maximum allowable liquid sizingpressure drop
FL Rated liquid pressure recoveryfactor, dimensionless
∆Pmax(LP) Maximum allowable sizing pressuredrop with attached fittings
FLP Combined liquid pressurerecovery factor and pipinggeometry factor of valve withattached fittings (when there areno attached fittings, FLP equalsFL), dimensionless
q Volume rate of flow
FP Piping geometry factor,dimensionless
qmax Maximum flow rate (choked flowconditions) at given upstreamconditions
Gf Liquid specific gravity (ratio ofdensity of liquid at flowingtemperature to density of water at60�F), dimensionless
T1 Absolute upstream temperature(degree K or degree R)
Gg Gas specific gravity (ratio ofdensity of flowing gas to density ofair with both at standardconditions(1), i.e., ratio ofmolecular weight of gas tomolecular weight of air),dimensionless
w Mass rate of flow
k Ratio of specific heats,dimensionless
x Ratio of pressure drop to upstreamabsolute static pressure (∆P/P1),dimensionless
K Head loss coefficient of a device,dimensionless
xT Rated pressure drop ratio factor,dimensionless
M Molecular weight, dimensionless Y Expansion factor (ratio of flowcoefficient for a gas to that for aliquid at the same Reynoldsnumber), dimensionless
N Numerical constant Z Compressibility factor,dimensionless
γ1 Specific weight at inlet conditions
υ Kinematic viscosity, centistokes
1. Standard conditions are defined as 60�F (15.5�C) and 14.7 psia (101.3kPa).
Chapter 5. Control Valve Selection
113
For rotary valves with reducers(swaged installations), Fp factors areincluded in the appropriate flow coeffi-cient table. For other valve designs
and fitting styles, determine the Fpfactors by using the procedure for De-termining Fp, the Piping GeometryFactor.
Equation Constants(1)
N w q p(2) � T d, D
N1
0.08650.8651.00
- - -- - -- - -
m3/hm3/hgpm
kPabarpsia
- - -- - -- - -
- - -- - -- - -
- - -- - -- - -
N20.00214
890- - -- - -
- - -- - -
- - -- - -
- - -- - -
- - -- - -
mminch
N50.00241
1000- - -- - -
- - -- - -
- - -- - -
- - -- - -
- - -- - -
mminch
N6
2.7327.363.3
kg/hkg/hlb/h
- - -- - -- - -
kPabarpsia
kg/m3
kg/m3
lb/ft3
- - -- - -- - -
- - -- - -- - -
N7(3)
Normal ConditionsTN = 0�C
3.94394
- - -- - -
m3/hm3/h
kPabar
- - -- - -
deg Kdeg K
- - -- - -
Standard ConditionsTs = 15.5�C
4.17417
- - -- - -
m3/hm3/h
kPabar
- - -- - -
deg Kdeg K
- - -- - -
Standard ConditionsTs = 60�F
1360 - - - scfh psia - - - deg R - - -
N8
0.94894.819.3
kg/hkg/hlb/h
- - -- - -- - -
kPabarpsia
- - -- - -- - -
deg Kdeg Kdeg R
- - -- - -- - -
N9(3)
Normal ConditionsTN = 0�C
21.22120
- - -- - -
m3/hm3/h
kPabar
- - -- - -
deg Kdeg K
- - -- - -
Standard ConditionsTs = 15.5�C
22.42240
- - -- - -
m3/hm3/h
kPabar
- - -- - -
deg Kdeg K
- - -- - -
Standard ConditionsTS = 60�F
7320 - - - scfh psia - - - deg R - - -
1. Many of the equations used in these sizing procedures contain a numerical constant, N, along with a numericalsubscript. These numerical constants provide a means for using different units in the equations. Values for the variousconstants and the applicable units are given in the above table. For example, if the flow rate is given in U.S. gpm andthe pressures are psia, N1 has a value of 1.00. If the flow rate is m3/hr and the pressures are kPa, the N1 constantbecomes 0.0865.2. All pressures are absolute.3. Pressure base is 101.3 kPa (1.013 bar)(14.7 psia).
4. Determine qmax (the maximum flowrate at given upstream conditions) or∆Pmax (the allowable sizing pressuredrop).
The maximum or limiting flow rate(qmax), commonly called choked flow,is manifested by no additional in-crease in flow rate with increasingpressure differential with fixed up-stream conditions. In liquids, chokingoccurs as a result of vaporization ofthe liquid when the static pressurewithin the valve drops below the vaporpressure of the liquid.
The IEC standard requires the cal-culation of an allowable sizing pres-sure drop (∆Pmax), to account for thepossibility of choked flow conditionswithin the valve. The calculated ∆Pmaxvalue is compared with the actualpressure drop specified in the serviceconditions, and the lesser of these twovalues is used in the sizing equation.If it is desired to use ∆Pmax to accountfor the possibility of choked flow con-ditions, it can be calculated using theprocedure for determining qmax, theMaximum Flow Rate, or ∆Pmax, theAllowable Sizing Pressure Drop. If itcan be recognized that choked flow
Chapter 5. Control Valve Selection
114
conditions will not develop within thevalve, ∆Pmax need not be calculated.
5. Solve for required Cv, using the ap-propriate equation:
� For volumetric flow rate units—
C� �q
N1FpP1�P2
Gf�
� For mass flow rate units—
Cv �w
N6Fp (P1 � P2)��
In addition to Cv, two other flow coeffi-cients, Kv and Av, are used, particular-ly outside of North America. The fol-lowing relationships exist:
Kv = (0.865)(Cv)
Av = (2.40 X 10−5)(Cv)
6. Select the valve size using the ap-propriate flow coefficient table and thecalculated Cv value.
Determining Fp , the PipingGeometry FactorDetermine an Fp factor if any fittingssuch as reducers, elbows, or tees willbe directly attached to the inlet andoutlet connections of the control valvethat is to be sized. When possible, it isrecommended that Fp factors be de-termined experimentally by using thespecified valve in actual tests. The Fpfactors for rotary valves used with re-ducers have all been determined inthis manner, and their values arelisted in the flow coefficient tables.
For Fp values not listed in the flow co-efficient tables, calculate the Fp factorusing the following equation.
Fp � �1 ��KN2�Cv
d2�
2
��12
where,
N2 = Numerical constant found inthe Equation Constants table
d = Assumed nominal valve size
Cv = Valve sizing coefficient at100-percent travel for the as-sumed valve size
In the above equation, the �K term isthe algebraic sum of the velocity headloss coefficients of all of the fittingsthat are attached to the control valve.
�K = K1 + K2 + KB1 − KB2
where,
K1 = Resistance coefficient of up-stream fittings
K2 = Resistance coefficient ofdownstream fittings
KB1 = Inlet Bernoulli coefficient
KB2 = Outlet Bernoulli coefficient
The Bernoulli coefficients, KB1 andKB2, are used only when the diameterof the piping approaching the valve isdifferent from the diameter of the pip-ing leaving the valve, whereby:
KB1 or KB2 = 1 − �dD�
4
where,
d = Nominal valve size
D = Internal diameter of piping
If the inlet and outlet piping are ofequal size, then the Bernoulli coeffi-cients are also equal, KB1 = KB2, andtherefore they are dropped from theequation.
The most commonly used fitting incontrol valve installations is theshort-length concentric reducer. Theequations for this fitting are as follows:
� For an inlet reducer—
K1 � 0.5�1 �d2
D2�
2
Chapter 5. Control Valve Selection
115
� For an outlet reducer—
K2 � 1.0�1 �d2
D2�
2
� For a valve installed betweenidentical reducers—
K1 � K2 � 1.5�1 �d2
D2�
2
Determining qmax (the MaximumFlow Rate) or �Pmax (theAllowable Sizing PressureDrop)
Determine either qmax or �Pmax if it ispossible for choked flow to developwithin the control valve that is to besized. The values can be determinedby using the following procedures.
Determining qmax (the MaximumFlow Rate)
qmax � N1FLCvP1 � FF Pv
Gf
�
Values for FF, the liquid critical pres-sure ratio factor, can be obtained fromfigure 5-2, or from the following equa-tion:
FF � 0.96 � 0.28Pv
Pc�
Values of FL, the recovery factor forvalves installed without fittings at-tached, can be found in the flow coef-ficient tables. If the given valve is tobe installed with fittings such as re-ducer attached to it, FL in the equationmust be replaced by the quotientFLP/Fp, where:
FLP � �K1
N2�Cv
d2�
2
�1
FL2�
�12
and
K1 = K1 + KB1
where,
K1 = Resistance coefficient of up-stream fittings
KB1 = Inlet Bernoulli coefficient
(See the procedure for DeterminingFp, the Piping Geometry Factor, fordefinitions of the other constants andcoefficients used in the above equa-tions.)
Determining �Pmax (theAllowable Sizing PressureDrop)�Pmax (the allowable sizing pressuredrop) can be determined from the fol-lowing relationships:
For valves installed without fittings—
�Pmax(L) � FL2�P1 � FF Pv�
For valves installed with fittings at-tached—
�Pmax(LP) � �FLP
FP�
2
�P1 � FF PV�
where,
P1 = Upstream absolute staticpressure
P2= Downstream absolute staticpressure
Pv = Absolute vapor pressure at in-let temperature
Values of FF, the liquid critical pres-sure ratio factor, can be obtained fromfigure 5-2 or from the following equa-tion:
FF � 0.96 � 0.28Pv
Pc�
Chapter 5. Control Valve Selection
116
Figure 5-2. Liquid Critical Pressure Ratio Factor for All Fluids
Values of FL, the recovery factor forvalves installed without fittings at-tached, can be found in the flow coef-ficient tables. An explanation of howto calculate values of FLP, the recov-ery factor for valves installed with fit-tings attached, is presented in the pro-cedure for determining qmax (theMaximum Flow Rate).
Once the �Pmax value has been ob-tained from the appropriate equation,it should be compared with the actualservice pressure differential (�P = P1− P2). If �Pmax is less than �P, this isan indication that choked flow condi-tions will exist under the service con-ditions specified. If choked flow condi-tions do exist (�Pmax < P1 − P2), thenstep 5 of the procedure for SizingValves for Liquids must be modifiedby replacing the actual service pres-sure differential (P1 − P2) in the ap-propriate valve sizing equation withthe calculated �Pmax value.
Note
Once it is known thatchoked flow conditionswill develop within thespecified valve design(�Pmax is calculated tobe less than �P), a fur-ther distinction can bemade to determinewhether the choked flowis caused by cavitationor flashing. The chokedflow conditions arecaused by flashing if theoutlet pressure of thegiven valve is less thanthe vapor pressure ofthe flowing liquid. Thechoked flow conditionsare caused by cavitationif the outlet pressure ofthe valve is greater thanthe vapor pressure ofthe flowing liquid.
Chapter 5. Control Valve Selection
117
Liquid Sizing Sample Problem
Assume an installation that, at initialplant start-up, will not be operating atmaximum design capability. The linesare sized for the ultimate system ca-pacity, but there is a desire to install acontrol valve now which is sized onlyfor currently anticipated requirements.The line size is 8 inches, and a Class300 globe valve with an equal per-centage cage has been specified.Standard concentric reducers will beused to install the valve into the line.Determine the appropriate valve size.
1. Specify the necessary variables re-quired to size the valve:
� Desired valve design—Class300 globe valve with equal percent-age cage and an assumed valve sizeof 3 inches.
� Process fluid—liquid propane
� Service conditions—
q = 800 gpm
P1 = 300 psig = 314.7 psia
P2 = 275 psig = 289.7 psia
�P = 25 psi
T1 = 70�F
Gf = 0.50
Pv = 124.3 psia
Pc = 616.3 psia
2. Determine an N1 value of 1.0 fromthe Equation Constants table.
3. Determine Fp, the piping geometryfactor.
Because it is proposed to install a3-inch valve in an 8-inch line, it will benecessary to determine the piping ge-ometry factor, Fp, which corrects forlosses caused by fittings attached tothe valve.
Fp � �1 ��KN2�Cv
d2�
2
��12
where,
N2 = 890, from the EquationConstants table
d = 3 in., from step 1
Cv = 121, from the flow coefficienttable for a Class 300, 3 in. Globevalve with equal percentage cage
To compute �K for a valve installedbetween identical concentric reducers:
�K � K1 � K2
� 1.5�1 �d2
D2�
2
� 1.5�1 �(3)2
(8)2�
2
� 1.11
where,
D = 8 in., the internal diameter ofthe piping so,
Fp � �1 �1.11890�121
32�
2
��12
� 0.90
4. Determine �Pmax (the AllowableSizing Pressure Drop.)
Based on the small required pressuredrop, the flow will not be choked(�Pmax > �P).
5. Solve for Cv, using the appropriateequation.
Cv �q
N1FP
P1�P2�
Gf
�800
(1.0)(0.90) 250.5
�
� 125.7
Chapter 5. Control Valve Selection
118
6. Select the valve size using the flowcoefficient table and the calculated Cvvalue.
The required Cv of 125.7 exceeds thecapacity of the assumed valve, whichhas a Cv of 121. Although for this ex-ample it may be obvious that the nextlarger size (4 inches) would be thecorrect valve size, this may not alwaysbe true, and a repeat of the aboveprocedure should be carried out.
Assuming a 4-inch valve, Cv = 203.This value was determined from theflow coefficient table for a Class 300,4-inch globe valve with an equal per-centage cage.
Recalculate the required Cv using anassumed Cv value of 203 in the Fpcalculation.
where,
�K � K1 � K2
� 1.5�1 �d2
D2�
2
� 1.5�1 �1664�
2
� 0.84
and
Fp � �1.0 ��KN2�Cv
d2�
2
��12
� �1.0 �0.84890�203
42�
2
��12
� 0.93
and
Cv �q
N1FpP1�P2
Gf�
�800
(1.0)(0.93) 250.5
�
� 121.7
This solution indicates only that the4-inch valve is large enough to satisfythe service conditions given. Theremay be cases, however, where amore accurate prediction of the Cv isrequired. In such cases, the requiredCv should be redetermined using anew Fp value based on the Cv valueobtained above. In this example, Cv is121.7, which leads to the following re-sult:
Fp � �1.0 ��KN2�Cv
d2�
2
��12
� �1.0 �0.84890�121.7
42�
2
��12
� 0.97
The required Cv then becomes:
Cv �q
N1FpP1�P2
Gf�
�800
(1.0)(0.97) 250.5
�
� 116.2
Because this newly determined Cv isvery close to the Cv used initially forthis recalculation (116.2 versus121.7), the valve sizing procedure iscomplete, and the conclusion is that a4-inch valve opened to about 75-per-cent of total travel should be adequatefor the required specifications.
Chapter 5. Control Valve Selection
119
Sizing Valves forCompressible FluidsFollowing is a six-step procedure forthe sizing of control valves for com-pressible flow using the ISA standard-ized procedure. Each of these steps isimportant and must be consideredduring any valve sizing procedure.Steps 3 and 4 concern the determina-tion of certain sizing factors that mayor may not be required in the sizingequation depending on the serviceconditions of the sizing problem. If it isnecessary for one or both of these siz-ing factors to be included in the sizingequation for a particular sizing prob-lem, refer to the appropriate factor de-termination section(s), which is refer-enced and located in the followingtext.
1. Specify the necessary variables re-quired to size the valve as follows:
� Desired valve design (e.g. bal-anced globe with linear cage); refer tothe appropriate valve flow coefficienttable
� Process fluid (air, natural gas,steam, etc.) and
� Appropriate service conditions—
q, or w, P1, P2 or �P, T1, Gg, M, k,Z, and �1
The ability to recognize which termsare appropriate for a specific sizingprocedure can only be acquiredthrough experience with differentvalve sizing problems. If any of theabove terms appear to be new or un-familiar, refer to the Abbreviations andTerminology table for a complete defi-nition.
2. Determine the equation constant,N. N is a numerical constant con-tained in each of the flow equations toprovide a means for using differentsystems of units. Values for these var-ious constants and their applicableunits are given in the EquationConstants table.
Use either N7 or N9 if sizing the valvefor a flow rate in volumetric units (scfhor m3/h). Which of the two constantsto use depends upon the specifiedservice conditions. N7 can be usedonly if the specific gravity, Gg, of thefollowing gas has been specifiedalong with the other required serviceconditions. N9 can be used only if themolecular weight, M, of the gas hasbeen specified.
Use either N6 or N8 if sizing the valvefor a flow rate in mass units (lb/h orkg/h). Which of the two constants touse depends upon the specified ser-vice conditions. N6 can be used only ifthe specific weight, �1, of the flowinggas has been specified along with theother required service conditions. N8can be used only if the molecularweight, M, of the gas has been speci-fied.
3. Determine Fp, the piping geometryfactor. Fp is a correction factor that ac-counts for any pressure losses due topiping fittings such as reducers, el-bows, or tees that might be attacheddirectly to the inlet and outlet connec-tions of the control valves to be sized.If such fittings are attached to thevalve, the Fp factor must be consid-ered in the sizing procedure. If, how-ever, no fittings are attached to thevalve, Fp has a value of 1.0 and sim-ply drops out of the sizing equation.
Also, for rotary valves with reducers,Fp factors are included in the ap-propriate flow coefficient table. Forother valve designs and fitting styles,determine the Fp factors by using theprocedure for Determining Fp the Pip-ing Geometry Factor, which is locatedin the section for Sizing Valves for Liq-uids.
4. Determine Y, the expansion factor,as follows:
Y � 1 �x
3Fk xT
Chapter 5. Control Valve Selection
120
where,
Fk = k/1.4, the ratio of specificheats factor
k = Ratio of specific heats
x = �P/P1, the pressure drop ratio
xT = The pressure drop ratio factorfor valves installed without at-tached fittings. More definitively,xT is the pressure drop ratio re-quired to produce critical, ormaximum, flow through thevalve when Fk = 1.0
If the control valve to be installed hasfittings such as reducers or elbows at-tached to it, then their effect is ac-counted for in the expansion factorequation by replacing the xT term witha new factor xTP. A procedure for de-termining the xTP factor is described inthe section for Determining xTP, thePressure Drop Ratio Factor.
Note
Conditions of criticalpressure drop are real-ized when the value of xbecomes equal to or ex-ceeds the appropriatevalue of the product ofeither Fk xT or Fk xTP atwhich point:
y � 1 �x
3Fk xT� 1 � 13 � 0.667
Although in actual service, pressuredrop ratios can, and often will, exceedthe indicated critical values, this is thepoint where critical flow conditions de-velop. Thus, for a constant P1, de-creasing P2 (i.e., increasing �P) willnot result in an increase in the flowrate through the valve. Values of x,therefore, greater than the product ofeither FkxT or FkxTP must never besubstituted in the expression for Y.This means that Y can never be lessthan 0.667. This same limit on valuesof x also applies to the flow equationsthat are introduced in the next section.
5. Solve for the required Cv using theappropriate equation:
For volumetric flow rate units—
� If the specific gravity, Gg, of thegas has been specified:
Cv �q
N7 Fp P1 Y xGg T1 Z�
� If the molecular weight, M, of thegas has been specified:
Cv �q
N9 Fp P1 Y xM T1 Z�
For mass flow rate units—
� If the specific weight, �1, of thegas has been specified:
Cv �w
N6FpY x P1 �1�
� If the molecular weight, M, of thegas has been specified:
Cv �w
N8 Fp P1 Yx M
T1 Z�
In addition to Cv, two other flow coeffi-cients, Kv and Av, are used, particular-ly outside of North America. The fol-lowing relationships exist:
Kv � (0.865)(Cv)
Av � �2.40 X 10�5�(Cv)
6. Select the valve size using the ap-propriate flow coefficient table and thecalculated Cv value.
Note
Once the valve sizingprocedure is completed,consideration can bemade for aerodynamicnoise prediction. To de-termine the gas flow siz-ing coefficient (Cg) foruse in the aerodynamicnoise prediction tech-
Chapter 5. Control Valve Selection
121
nique, use the followingequation:
Cg � 40 Cv xT�
Determining xTP, thePressure Drop RatioFactorIf the control valve is to be installedwith attached fittings such as reducersor elbows, then their effect is ac-counted for in the expansion factorequation by replacing the xT term witha new factor, xTP.
xTP �
xT
Fp2�1 �
xT Ki
N5�Cv
d 2�
2
��1
where,
N5 = Numerical constant found inthe Equation Constants table
d = Assumed nominal valve size
Cv = Valve sizing coefficient fromflow coefficient table at 100 per-cent travel for the assumedvalve size
Fp = Piping geometry factor
xT = Pressure drop ratio for valvesinstalled without fittings at-tached. xT values are includedin the flow coefficient tables
In the above equation, Ki, is the inlethead loss coefficient, which is definedas:
Ki � K1 � KB1
where,
K1 = Resistance coefficient of up-stream fittings (see the proce-dure for Determining Fp, thePiping Geometry Factor, whichis contained in the section forSizing Valves for Liquids).
KB1 = Inlet Bernoulli coefficient(see the procedure for Deter-
mining Fp, the piping Geometryfactor, which is contained in thesection for Sizing Valves for Liq-uids.)
Compressible Fluid SizingSample Problem No. 1
Determine the size and percent open-ing for a Fisher Design V250 ballvalve operating with the following ser-vice conditions. Assume that the valveand line size are equal.
1. Specify the necessary variables re-quired to size the valve:
� Desired valve design—DesignV250 valve
� Process fluid—Natural gas
� Service conditions—
P1 = 200 psig = 214.7 psia
P2 = 50 psig = 64.7 psia
�P = 150 psi
x = �P/P1 = 150/214.7 = 0.70
T1 = 60�F = 520�R
M = 17.38
Gg = 0.60
k = 1.31
q = 6.0 x 106 scfh
2. Determine the appropriate equationconstant, N, from the EquationConstants table.
Because both Gg and M have beengiven in the service conditions, it ispossible to use an equation containingeither N7 or N9. In either case, the endresult will be the same. Assume thatthe equation containing Gg has beenarbitrarily selected for this problem.Therefore N7 = 1360.
Chapter 5. Control Valve Selection
122
3. Determine Fp, the piping geometryfactor. Since valve and line size areassumed equal, Fp = 1.0.
4. Determine Y, the expansion factor.
Fk �k
1.40
�1.311.40
� 0.94
It is assumed that an 8-inch DesignV250 valve will be adequate for thespecified service conditions. From theflow coefficient table, xT for an 8-inchDesign V250 valve at 100-percenttravel is 0.137.
x = 0.70 (This was calculated instep 1.)
Since conditions of critical pressuredrop are realized when the calculatedvalue of x becomes equal to or ex-ceeds the appropriate value of FkxT,these values should be compared.
FkxT � (0.94) (0.137)
� 0.129
Because the pressure drop ratio, x =0.70 exceeds the calculated criticalvalue, FkxT = 0.129, choked flow con-ditions are indicated. Therefore, Y =0.667, and x = FKXT = 0.129.
5. Solve for required Cv using the ap-propriate equation.
Cv �q
N7 Fp P1 Y xGg T1 Z�
The compressibility factor, Z, can beassumed to be 1.0 for the gas pres-sure and temperature given andFp = 1 because valve size and linesize are equal.
So,
Cv �6.0 x 106
�1360��1.0��214.7��0.667� 0.129(0.6)(520)(1.0)�
� 1515
6. Select the valve size using the ap-propriate flow coefficient table and thecalculated Cv value.
The above result indicates that thevalve is adequately sized (rated Cv =2190). To determine the percent valveopening, note that the required Cv oc-curs at approximately 83 degrees forthe 8-inch Design V250 valve. Notealso that, at 83 degrees opening, thexT value is 0.252, which is substantial-ly different from the rated value of0.137 used initially in the problem.The next step is to rework the problemusing the xT value for 83 degrees trav-el.
The Fk xT product must now be recal-culated.
x � Fk xT
� (0.94) (0.252)
� 0.237
The required Cv now becomes:
Cv �q
N7 Fp P1 Y xGg T1 Z�
�
6.0 x 106
�1360��1.0��214.7��0.667� 0.237(0.6)(520)(1.0)
�
� 1118
The reason that the required Cv hasdropped so dramatically is attributablesolely to the difference in the xT val-ues at rated and 83 degrees travel. ACv of 1118 occurs between 75 and 80degrees travel.
The appropriate flow coefficient tableindicates that xT is higher at 75 de-grees travel than at 80 degrees travel.Therefore, if the problem were to bereworked using a higher xT value, thisshould result in a further decline in thecalculated required Cv.
Chapter 5. Control Valve Selection
123
Reworking the problem using the xTvalue corresponding to 78 degreestravel (i.e., xT = 0.328) leaves:
x � Fk xT
� (0.94) (0.328)
� 0.308
and,
Cv �q
N7 Fp P1 Y xGg T1 Z�
�
6.0 x 106
(1360)(1.0)(214.7)(0.667) 0.308(0.6)(520)(1.0)
�
� 980
The above Cv of 980 is quite close tothe 75 degree travel Cv. The problemcould be reworked further to obtain amore precise predicted opening; how-ever, for the service conditions given,an 8-inch Design V250 valve installedin an 8-inch line will be approximately75 degrees open.
Compressible Fluid SizingSample Problem No. 2Assume steam is to be supplied to aprocess designed to operate at 250psig. The supply source is a headermaintained at 500 psig and 500�F. A6-inch line from the steam main to theprocess is being planned. Also, makethe assumption that if the requiredvalve size is less than 6 inches, it willbe installed using concentric reducers.Determine the appropriate Design EDvalve with a linear cage.
1. Specify the necessary variables re-quired to size the valve:
a. Desired valve design—Class300 Design ED valve with a linearcage. Assume valve size is 4 inch-es.
b. Process fluid—superheatedsteam
c. Service conditions—
w = 125,000 lb/h
P1 = 500 psig = 514.7 psia
P2 = 250 psig = 264.7 psia
�P = 250 psi
x = �P/P1 = 250/514.7 = 0.49
T1 = 500�F
�1 = 1.0434 lb/ft3 (from Proper-ties of Saturated Steam table)
k= 1.28 (from Properties of Sat-urated Steam table)
2. Determine the appropriate equationconstant, N, from the EquationConstants table.
Because the specified flow rate is inmass units, (lb/h), and the specificweight of the steam is also specified,the only sizing equation that can beused is that which contains the N6constant. Therefore,
N6 � 63.3
3. Determine Fp, the piping geometryfactor.
Fp � �1 ��KN2�Cv
d2�
2
��12
where,
N2 = 890, determined from theEquation Constants table
d = 4 in.
Cv = 236, which is the value listedin the manufacturer’s Flow Co-efficient table for a 4-inch De-sign ED valve at 100-percent to-tal travel.
and
�K � K1 � K2
� 1.5�1 �d2
D2�
2
Chapter 5. Control Valve Selection
124
� 1.5�1 �42
62�
2
� 0.463
Finally:
Fp ��
�1 �
0.463890�(1.0)(236)
(4)2 �2
�
�12
� 0.95
4. Determine Y, the expansion factor.
Y � 1 �x
3Fk xTP
where,
Fk �k
1.40
�1, 281.40
� 0.91
x � 0.49 (As calculated in step1.)
Because the 4-inch valve is to beinstalled in a 6-inch line, the xT termmust be replaced by xTP.
xTP �
xT
Fp2�1 �
xT Ki
N5�Cv
d2�
2
��1
where,
N5 = 1000, from the EquationConstants table
d = 4 in.
Fp = 0.95, determined in step 3
xT = 0.688, a value determinedfrom the appropriate listing inthe manufacturer’s Flow Coeffi-cient table
Cv = 236, from step 3
and
Ki � K1 � KB1
� 0.5�1 �d2
D2�
2
��1 ��dD�
4
�
� 0.5�1 �42
62�
2
��1 � �46�
4
�
� 0.96
where D = 6 in.
so:
XTP �0.690.952�1
�0.69��0.96�
1000�236
42�
2
��1
� 0.67
Finally:
Y � 1 �x
3 Fk xTP
� 1 �0.49
(3) (0.91) (0.67)
� 0.73
5. Solve for required Cv using the ap-propriate equation.
Cv �w
N6 FP Y x P1 �1�
Cv �125, 000
(63.3)(0.95)(0.73) (0.49)(514.7)(1.0434)�
� 176
6. Select the valve size using the ap-propriate manufacturer’s Flow Coeffi-cient table and the calculated Cv val-ue.
Chapter 5. Control Valve Selection
125
Refer to the manufacturer’s Flow Co-efficient tables for Design ED valveswith linear cage. Because the as-sumed 4-inch valve has a Cv of 236 at100-percent travel and the next small-er size (3 inches) has a Cv of only148, it can be surmised that the as-sumed size is correct. In the event
that the calculated required Cv hadbeen small enough to have been han-dled by the next smaller size or if ithad been larger than the rated Cv forthe assumed size, it would have beennecessary to rework the problemagain using values for the new as-sumed size.
Ch
apter 5. C
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126 Representative Sizing Coefficients for Single−Ported Globe Style Valve Bodies
Valve Size(inches)
Valve Plug Style Flow Characteristic Port Dia.(in.)
RatedTravel(in.)
CV FL XT FD
1/2 Post Guided Equal Percentage 0.38 0.50 2.41 0.90 0.54 0.61
3/4 Post Guided Equal Percentage 0.56 0.50 5.92 0.84 0.61 0.61
1
Micro Form�
Cage Guided
Equal Percentage
LinearEqual Percentage
3/81/23/4
1 5/161 5/16
3/43/43/43/43/4
3.074.918.84
20.617.2
0.890.930.970.840.88
0.660.800.920.640.67
0.720.670.620.340.38
1 1/2
Micro−Form�
Cage Guided
Equal Percentage
LinearEqual Percentage
3/81/23/4
1 7/81 7/8
3/43/43/43/43/4
3.205.18
10.239.235.8
0.840.910.920.820.84
0.650.710.800.660.68
0.720.670.620.340.38
2 Cage Guided LinearEqual Percentage
2 5/162 5/16
1 1/81 1/8
72.959.7
0.770.85
0.640.69
0.330.31
3 Cage Guided LinearEqual Percentage
3 7/16 1 1/2 148136
0.820.82
0.620.68
0.300.32
4 Cage Guided LinearEqual Percentage
4 3/8 2 236224
0.820.82
0.690.72
0.280.28
6 Cage Guided LinearEqual Percentage
7 2 433394
0.840.85
0.740.78
0.280.26
8 Cage Guided LinearEqual Percentage
8 3 846818
0.870.86
0.810.81
0.310.26
Ch
apter 5. C
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127
Representative Sizing Coefficients for Rotary Shaft Valves
Valve Size(inches)
Valve Style Degrees of ValveOpening
Cv FL XT FD
1 V−Notch Ball Valve 6090
. 15.634.0
0.860.86
0.530.42
1 1/2 V−Notch Ball Valve 6090
28.577.3
0.850.74
0.500.27
2 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
59.213258.980.2
0.810.770.760.71
0.530.410.500.44
0.490.70
3 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
120321115237
0.800.740.810.64
0.500.300.460.28
0.920.990.490.70
4 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
195596270499
0.800.620.690.53
0.520.220.320.19
0.920.990.490.70
6 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
3401100664
1260
0.800.580.660.55
0.520.200.330.20
0.910.990.490.70
8 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
518182011602180
0.820.540.660.48
0.540.180.310.19
0.910.990.490.70
10 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
1000300016703600
0.800.560.660.48
0.470.190.380.17
0.910.990.490.70
(continued)
Ch
apter 5. C
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128 Representative Sizing Coefficients for Rotary Shaft Valves (continued)Valve Size(inches) FDXTFLCv
Degrees of ValveOpeningValve Style
12 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
1530398025005400
0.780.63
0.490.25
0.920.990.490.70
16 V−Notch Ball Valve
High Performance Butterfly Valve
60906090
2380827038708600
0.800.370.690.52
0.450.130.400.23
0.921.00
Chapter 5. Control Valve Selection
129
Actuator SizingActuators are selected by matchingthe force required to stroke the valvewith an actuator that can supply thatforce. For rotary valves a similar pro-cess matches the torque required tostroke the valve with an actuator thatwill supply that torque. The same fun-damental process is used for pneu-matic, electric, and electrohydraulicactuators.
Globe ValvesThe force required to operate a globevalve includes:
� Force to overcome static unbal-ance of the valve plug
� Force to provide a seat load
� Force to overcome packing fric-tion
� Additional forces required forcertain specific applications orconstructions
Total force required = A + B + C + D
A. Unbalance Force
The unbalance force is that resultingfrom fluid pressure at shutoff and inthe most general sense can be ex-pressed as:
Unbalance force = net pressure differ-ential X net unbalance area
Frequent practice is to take the maxi-mum upstream gauge pressure as thenet pressure differential unless theprocess design always ensures aback pressure at the maximum inletpressure. Net unbalance area is theport area on a single seated flow updesign. Unbalance area may have totake into account the stem area de-pending on configuration. For bal-anced valves there is still a small un-balance area. This data can beobtained from the manufacturer. Typi-cal port areas for balance valves flowup and unbalanced valves in a flowdown configuration are listed below;
Typical Unbalance Areas of Control Valves
Port DiameterUnbalance AreaSingle seated
unbalanced valves
Unbalance AreaBalanced Valves
1/4 .028 - - -
3/8 0.110 - - -
1/2 0.196 - - -
3/4 0.441 - - -
1 0.785 - - -
1 5/16 1.35 0.04
1 7/8 2.76 0.062
2 5/16 4.20 0.27
3 7/16 9.28 0.118
4 3/8 15.03 0.154
7 38.48 0.81
8 50.24 0.86
Chapter 5. Control Valve Selection
130
Figure 5-3. Minimum Required Seat Load for Metal-Seated Valves forImproved Seat Life for Class II-V and Recommended Seat Load for
Optimum Performance in Boiler Feedwater Service
900
800
700
600
500
400
300
200
100
0
0 1000 2000 3000 4000 5000 6000
SHUTOFF PRESSURE DROP, PSI
RE
QU
IRE
D S
EA
T L
OA
D (
LB
PE
R L
INE
AL
INC
H)
A2222−4
CLASS V (METAL SEAT)
CLASS IV
CLASS III
CLASS II
1000
CLASS V (METAL SEAT WITH C−SEAL TRIM)
CLASS V (METAL SEAT FOR OPTIMUM PER-FORMANCE AND LIFE IN BOILER FEEDWATERSERVICE.
Leak Class Recommended Seat Load
Class I As required by user specification, no factory leak test required
Class II 20 pounds per lineal inch of port circumference
Class III 40 pounds per lineal inch of port circumference
Class IV
Standard (Lower) Seat only—40 pounds per lineal inch of port circumference(up through a 4-3/8 inch diameter port)Standard (Lower) Seat only—80 pounds per lineal inch of port circumference(larger than 4-3/8 inch diameter port)
Class V Metal Seat—determine pounds per lineal inch of port circumference fromfigure 5-3
Class VI Metal Seat—300 pounds per lineal inch of port circumference
B. Force to Provide Seat LoadSeat load, usually expressed inpounds per lineal inch of port circum-ference, is determined by shutoff re-
quirements. Use the following guide-lines to determine the seat loadrequired to meet the factory accep-tance tests for ANSI/FCI 70-2 and IEC
Chapter 5. Control Valve Selection
131
534-4 leak classes II through VI. Seetable for recommended seat load.
Because of differences in the severityof service conditions, do not construethese leak classifications and corre-sponding leakage rates as indicatorsof field performance. To prolong seatlife and shutoff capabilities, use ahigher than recommended seat load.See Figure 5-3 for suggested seatloads. If tight shutoff is not a primeconsideration, use a lower leak class.
C. Packing Friction
Packing friction is determined by stemsize, packing type, and the amount ofcompressive load placed on the pack-ing by the process or the bolting.Packing friction is not 100% repeat-able in its friction characteristics. Liveloaded packing designs can have sig-nificant friction forces especially ifgraphite packing is used. The tablebelow lists typical packing friction val-ues.
Chapter 5. Control Valve Selection
132
Typical Packing Friction Values
STEM SIZE(INCHES) CLASS
PTFE PACKING GRAPHITERIBBON/
FILAMENTSingle Double
5/16 All 20 30 - - -
3/8
125150250300 38 56
- - -125- - -190
600900
1500
250320380
1/2
125150250300
50 75
- - -180- - -230
600900
15002500
320410500590
5/8
125150250300600
63 95
- - -218- - -290400
3/4
125150250300
75 112.5
- - -350- - -440
600900
15002500
66088011001320
1
300600900
15002500
100 150
610850
106013001540
1-1/4
300600900
15002500
120 180
8001100140017002040
2
300600900
15002500
200 300
12251725225027503245
Values shown are frictional forces typically encountered when using standard packing flange bolt torquing procedures.
D. Additional Forces
Additional forces may be required tostroke the valve such as: bellow stiff-ness; unusual frictional forces result-
ing from seals; or special seatingforces for soft metal seals as an ex-ample. The manufacturer should ei-ther supply this information or take itinto account when sizing an actuator.
Chapter 5. Control Valve Selection
133
Actuator Force Calculations
Pneumatic diaphragm actuators pro-vide a net force with the additional airpressure after compressing the springin air to close, or with the net precom-pression of the spring in air to open.This may be calculated in pounds persquare inch of pressure differential.
For example: Suppose 275 lbf. is re-quired to close the valve calculatedfollowing the process described earli-er. An air-to-open actuator with 100square inches of diaphragm area anda bench set of 6 to 15 psig is oneavailable option. The expected operat-ing range is 3 to 15 psig. The precom-pression can be calculated as the dif-ference between the lower end of thebench set (6 psig) and the beginningof the operating range (3 psig). This 3psig is used to overcome the precom-pression so the net precompressionforce must be;
3 psig X 100 sq. in. = 300 lbf.
This exceeds the force required and isan adequate selection.
Piston actuators with springs aresized in the same manner. The thrustfrom piston actuators without springscan simply be calculated as:
(Piston Area)(Minimum SupplyPressure) = Available Thrust
(be careful to maintain compatibility ofunits)
In some circumstances an actuatorcould supply too much force andcause the stem to buckle, to bend suf-ficiently to cause a leak, or to damagevalve internals. This could occur be-cause the actuator is too large or the
maximum air supply exceeds the mini-mum air supply available.
The manufacturer normally takes re-sponsibility for actuator sizing andshould have methods documented tocheck for maximum stem loads.Manufacturers also publish data onactuator thrusts, effective diaphragmareas, and spring data.
Rotary Actuator SizingIn selecting the most economical ac-tuator for a rotary valve, the determin-ing factors are the torque required toopen and close the valve and thetorque output of the actuator.
This method assumes the valve hasbeen properly sized for the applicationand the application does not exceedpressure limitations for the valve.
Torque EquationsRotary valve torque equals the sum ofa number of torque components. Toavoid confusion, a number of thesehave been combined and a number ofcalculations have been performed inadvance. Thus, the torques requiredfor each valve type can be repre-sented with two simple and practicalequations.
Breakout TorqueTB = A(�Pshutoff) + B
Dynamic TorqueTD = C(�Peff)
The specific A, B, and C factors foreach valve design are included in fol-lowing tables.
Chapter 5. Control Valve Selection
134
Typical Rotary Shaft Valve Torque FactorsV−Notch Ball Valve with Composition Seal
VALVESIZE,
INCHES
VALVESHAFT
DIAMETER,INCHES
A
B
C MAXIMUM TD,
LBF�IN.Composition
Bearings60
Degrees70
Degrees
23468
1/23/43/41
1-1/4
0.150.100.101.801.80
80280380500750
0.110.151.101.103.80
0.603.80
18.036.060.0
5152120212041409820
101214161820
1-1/41-1/21-3/4
22-1/82-1/2
1.804.00
42606097
125030002400280028005200
3.8011.075
105105190
125143413578578
1044
982012,00023,52523,52555,76255,762
High Performance Butterfly Valve with Composition Seal
VALVESIZE,
INCHES
SHAFTDIAMETER
INCHESA B
C MAXIMUM TORQUE,INCH-POUNDS
60� 75� 90� BreakoutTB
Dynamic TD
3 1/2 0.50 136 0.8 1.8 8 280 515
4 5/8 0.91 217 3.1 4.7 25 476 1225
6 3/4 1.97 403 30 24 70 965 2120
8 1 4.2 665 65 47 165 1860 4140
10 1-1/4 7.3 1012 125 90 310 3095 9820
12 1-1/2 11.4 1422 216 140 580 4670 12,000
Maximum Rotation
Maximum rotation is defined as theangle of valve disk or ball in the fullyopen position.
Normally, maximum rotation is 90 de-grees. The ball or disk rotates 90 de-grees from the closed position to thewide open position.
Some of the pneumatic spring-returnpiston and pneumatic spring-and-dia-phragm actuators are limited to 60 or75 degrees rotation.
For pneumatic spring-and-diaphragmactuators, limiting maximum rotationallows for higher initial spring com-pression, resulting in more actuatorbreakout torque. Additionally, the ef-fective length of each actuator leverchanges with valve rotation. Publishedtorques, particularly for pneumatic pis-
ton actuators, reflect this changing le-ver length.
Non-Destructive TestProceduresSuccessful completion of specific non-destructive examinations is requiredfor valves intended for nuclear serviceand may be required by codes or cus-tomers in non-nuclear applications,particularly in the power industry.Also, successful completion of the ex-aminations may permit uprating ofASME Standard Class buttweldingend valves to a Special Class rating.The Special Class rating permits useof the butt-welding end valves at high-er pressures than allowed for Stan-dard Class valves. Procedures re-quired for uprating to the SpecialClass are detailed in ASME StandardB16.34.
Chapter 5. Control Valve Selection
135
While it is not feasible to present com-plete details of code requirements fornon-destructive examinations, thisbook will summarize the principlesand procedures of four major types ofnon-destructive examinations definedin ANSI, ASME, and ASTM standards.
Magnetic Particle (Surface)Examination
Magnetic particle examination can beused only on materials which can bemagnetized. The principle includesapplication of a direct current across apiece to induce a magnetic field in thepiece. Surface or shallow subsurfacedefects distort the magnetic field tothe extent that a secondary magneticfield develops around the defect. If amagnetic powder, either dry or sus-pended in liquid, is spread over themagnetized piece, areas of distortedmagnetic field will be visible, indicat-ing a defect in the piece in the area ofdistortion. After de-magnetizing thepiece by reversing the electric current,it may be possible to weld repair thedefect (normal procedure with cast-ings) or it may be necessary to re-place the piece (normal procedurewith forgings and bar stock parts). Af-ter repair or replacement, the magnet-ic particle examination must be re-peated.
Liquid Penetrant (Surface)Examination
This examination method permitsdetection of surface defects not visibleto the naked eye. The surface to beexamined is cleaned thoroughly anddried. The liquid penetrant dye, eitherwater or solvent soluble, is applied bydipping, brushing, or spraying, and al-lowed time to penetrate. Excess pene-trant is washed or wiped off (depend-ing on the penetrant used). Thesurface is again thoroughly dried anda developer (liquid or powder) is ap-plied. Inspection is performed under
the applicable light source. (Some de-velopers require use of an ultravioletor black light to expose defectiveareas). If defects are discovered andrepaired by welding, the piece mustbe re-examined after repair.
Radiographic (Volumetric)Examination
Radiography of control valve partsworks on the principle that X-rays andgamma rays will pass through metalobjects which are impervious to lightrays and will expose photographic filmjust as light rays will. The number andintensity of the rays passing throughthe metal object depend on the densi-ty of the object. Subsurface defectsrepresent changes in density of thematerial and can therefore bephotographed radiographically. Thepiece to be inspected is placed be-tween the X-ray or gamma ray sourceand the photographic film. Detail andcontrast sensitivity are determined byradiographing one or more small flatplates of specified thickness at thesame time the test subject is exposed.The small flat plate, called a penetra-meter, has several holes of specifieddiameters drilled in it. Its image on theexposed film, along with the valvebody or other test subject, makes itpossible to determine the detail andcontrast sensitivity of the radiograph.
Radiography can detect such castingdefects as gas and blowholes, sandinclusions, internal shrinkage, cracks,hot tears, and slag inclusions. In cast-ings for nuclear service, some defectssuch as cracks and hot tears are ex-pressly forbidden and cannot be re-paired. The judgment and experienceof the radiographer is important be-cause he must compare the radio-graph with the acceptance criteria(ASTM reference radiographs) to de-termine the adequacy of the casting.When weld repairs are required, thecasting must be radiographed againafter the repair.
Chapter 5. Control Valve Selection
136
Ultrasonic (Volumetric)ExaminationThis method monitors sound wave re-flections from the piece being in-spected to determine the depth andsize of any defects. Ultrasonic ex-amination can detect foreign materialsand discontinuities in fine-grainedmetal and thus lends itself to volumet-ric examination of structures such asplate, bar, and forgings. The test isnormally conducted either with a spe-cial oil called a coupler or under waterto ensure efficient transmission ofsound waves. The sound waves aregenerated by a crystal probe and arereflected at each interface in the piecebeing tested, that is, at each outerface of the piece itself and at eachface of the damaged or malformed in-ternal portion. These reflections arereceived by the crystal probe and dis-played on a screen to reveal the loca-tion and severity of the defect.
Cavitation and Flashing
Choked Flow Causes Flashingand CavitationThe IEC liquid sizing standard calcu-lates an allowable sizing pressuredrop, �Pmax. If the actual pressuredrop across the valve, as defined bythe system conditions of P1 and P2, isgreater than �Pmax then either flash-ing or cavitation may occur. Structuraldamage to the valve and adjacent pip-ing may also result. Knowledge ofwhat is actually happening within thevalve will permit selection of a valvethat can eliminate or reduce the ef-fects of cavitation and flashing.
The physical phenomena label is usedto describe flashing and cavitation be-cause these conditions represent ac-tual changes in the form of the fluidmedia. The change is from the liquidstate to the vapor state and resultsfrom the increase in fluid velocity at orjust downstream of the greatest flowrestriction, normally the valve port. Asliquid flow passes through the restric-
Figure 5−4. Vena Contracta Illustration
P1 P2
RESTRIC-TION
VENACONTRACTA
FLOW
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tion, there is a necking down, or con-traction, of the flow stream. The mini-mum cross−sectional area of the flowstream occurs just downstream of theactual physical restriction at a pointcalled the vena contracta, as shown infigure 5−4.
To maintain a steady flow of liquidthrough the valve, the velocity mustbe greatest at the vena contracta,where cross sectional area is theleast. The increase in velocity (or ki-netic energy) is accompanied by asubstantial decrease in pressure (orpotential energy) at the vena contrac-ta. Further downstream, as the fluidstream expands into a larger area, ve-locity decreases and pressure in-creases. But, of course, downstreampressure never recovers completely toequal the pressure that existed up-stream of the valve. The pressure dif-ferential (�P) that exists across thevalve is a measure of the amount ofenergy that was dissipated in thevalve. Figure 5−5 provides a pressureprofile explaining the differing perfor-mance of a streamlined high recoveryvalve, such as a ball valve, and avalve with lower recovery capabilitiesdue to greater internal turbulence anddissipation of energy.
Regardless of the recovery character-istics of the valve, the pressure differ-ential of interest pertaining to flashingand cavitation is the differential be-tween the valve inlet and the venacontracta. If pressure at the vena con-tracta should drop below the vaporpressure of the fluid (due to increasedfluid velocity at this point) bubbles willform in the flow stream. Formation of
Chapter 5. Control Valve Selection
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Figure 5−5. Comparison of PressureProfiles for High and Low Recovery
Valves
P2
P1 P2HIGH RECOVERY
P2LOW RECOVERY
FLOW
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Figure 5−6. Typical Appearance ofFlashing Damage
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bubbles will increase greatly as venacontracta pressure drops further be-low the vapor pressure of the liquid. Atthis stage, there is no difference be-tween flashing and cavitation, but thepotential for structural damage to thevalve definitely exists.
If pressure at the valve outlet remainsbelow the vapor pressure of the liquid,the bubbles will remain in the down-stream system and the process is saidto have flashed. Flashing can produceserious erosion damage to the valvetrim parts and is characterized by asmooth, polished appearance of theeroded surface, as shown in figure5−6. Flashing damage is normallygreatest at the point of highest veloc-ity, which is usually at or near the seatline of the valve plug and seat ring.
Figure 5−7. Typical Appearance ofCavitation Damage
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On the other hand, if downstreampressure recovery is sufficient to raisethe outlet pressure above the vaporpressure of the liquid, the bubbles willcollapse, or implode, producing cavi-tation. Collapsing of the vapor bubblesreleases energy and produces a noisesimilar to what one would expect ifgravel were flowing through the valve.If the bubbles collapse in close prox-imity to solid surfaces in the valve, theenergy released will gradually tearaway the material leaving a rough,cinderlike surface as shown in figure5−7. Cavitation damage may extendto the adjacent downstream pipeline,if that is where pressure recovery oc-curs and the bubbles collapse. Ob-viously, high recovery valves tend tobe more subject to cavitation, sincethe downstream pressure is more like-ly to rise above the liquid’s vaporpressure.
Valve Selection for FlashingServiceAs shown in figure 5−6, flashing dam-age is characterized by a smooth, pol-ished appearance of the eroded sur-faces. To review, flashing occursbecause P2 is less than Pv. P2 is thepressure downstream of the valve andis a function of the downstream pro-cess and piping. Pv is a function ofthe fluid and operating temperature.Therefore, the variables that defineflashing are not directly controlled bythe valve. This further means there isno way for any control valve to pre-
Chapter 5. Control Valve Selection
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vent flashing. Since flashing cannotbe prevented by the valve the bestsolution is to select a valve with prop-er geometry and materials to avoid orminimize damage.
In general erosion is minimized by:
� preventing or reducing the par-ticle (liquid droplets in this case) im-pact with the valve surfaces
� making those surfaces as hardas possible
� lowering the velocity of the ero-sive flow
Selecting a valve with as few fluid di-rectional changes as possible pro-vides the least number of particle im-pacts. Sliding-stem angle valves aretraditional solutions which providesuch a flow path. Some rotary valves,such as eccentric rotary plug, and V−ball valves, also offer straight−throughflow paths. Valves with expanded flowareas downstream of the throttlingpoint are beneficial because the ero-sive velocity is reduced. For thoseareas where the fluid must impact thevalve surfaces, at the seating surfacesfor example, choose materials that areas hard as possible. Generally theharder the material the longer it willresist erosion.
Fluids that are both flashing and cor-rosive can be especially troublesome.Flashing water in a steel valve is anexample of the synergistic result ofboth corrosion and erosion. The watercauses corrosion of steel and theflashing causes erosion of the result-ant, soft, oxide layer; these combineto create damage worse than eitherindividual mechanism would. Thesolution in this case is to prevent thecorrosion by selecting, as a minimum,a low-alloy steel.
Valve Selection for CavitationService
Cavitation damage is characterized bya rough, cinder−like appearance ofthe eroded surface as shown in figure5-7. It is distinctly different from thesmooth, polished appearance causedby the erosion of flashing. The pre-vious section describes how cavitationoccurs when the vena contracta pres-sure is less than Pv, and P2 is greaterthan Pv. Cavitation can be treated byseveral means.
The first is to eliminate the cavitationand thus the damage by managingthe pressure drop. If the pressuredrop across the valve can be con-trolled such that the local pressurenever drops below the vapor pres-sure, then no vapor bubbles will form.Without vapor bubbles to collapse,there is no cavitation. To eliminatecavitation the total pressure dropacross the valve is split, using multi-ple-stage trims, into smaller portions.Each of these small drops keeps itsvena contracta pressure above thevapor pressure so no vapor bubblesare formed.
The second method does not elimi-nate the cavitation but rather mini-mizes or isolates the damage muchthe same as with flashing solutions.This method aims to isolate the cavi-tation from valve surfaces and toharden those surfaces that the cavita-tion does impact.
A third method is to change the sys-tem in a manner to prevent thecauses of cavitation. If the P2 can beraised enough so that the vena con-tracta pressure does not fall below thevapor pressure, that is the valve is nolonger choked, then cavitation will beavoided. P2 can be raised by movingthe valve to a location that has morestatic head on the downstream side.Applying an orifice plate or similarbackpressure device can also raiseP2 at the valve; the downside is the
Chapter 5. Control Valve Selection
139
potential for the cavitation to transferfrom the valve to the orifice plate.
Noise Prediction
AerodynamicIndustry leaders use the InternationalElectrotechnical Commission standardIEC 534-8-3: Industrial-process con-trol valves—Part 8: Noise Consider-ations—Section 3: Control valve aero-dynamic noise prediction method.This method consists of a mix of ther-modynamic and aerodynamic theoryand some empirical information. Thedesign of the method allows a noiseprediction for a valve based only onthe measurable geometry of the valveand the service conditions applied tothe valve. There is no need for specif-ic empirical data for each valve designand size. Because of this pure analyti-cal approach to valve noise predictionthe IEC method allows an objectiveevaluation of alternatives.
The method defines five basic stepsto a noise prediction:
1—Calculate the total stream powerin the process at the vena contrac-ta. The noise of interest is generatedby the valve in and downstream of thevena contracta. If the total power dis-sipated by throttling at the vena con-tracta can be calculated, then the frac-tion that is noise power can bedetermined. Since power is the timerate of energy, a form of the familiarequation for calculating kinetic energycan be used. The kinetic energy equa-tion is 1/2 mv2 where m is mass and vis velocity. If the mass flow rate is sub-stituted for the mass term, then theequation calculates the power. Thevelocity is the vena contracta velocityand is calculated with the energyequation of the First Law of Thermo-dynamics.
2—Determine the fraction of totalpower that is acoustic power. Themethod considers the process condi-tions applied across the valve to de-
termine the particular noise generat-ing mechanism in the valve. There arefive defined regimes dependent on therelationship of the vena contractapressure and the downstream pres-sure. For each of these regimes anacoustic efficiency is defined and cal-culated. This acoustic efficiency es-tablishes the fraction of the totalstream power, as calculated in Step 1,which is noise power. In designing aquiet valve, lower acoustic efficiencyis one of the goals.
3—Convert acoustic power tosound pressure. The final goal of theIEC prediction method is determina-tion of the sound pressure level at areference point outside the valvewhere human hearing is a concern.Step 2 delivers acoustic power, whichis not directly measurable. Acoustic orsound pressure is measurable andtherefore has become the default ex-pression for noise in most situations.Converting from acoustic power to thesound pressure uses basic acoustictheory.
4—Account for the transmissionloss of the pipewall and restate thesound pressure at the outside sur-face of the pipe. Steps 1 through 3are involved with the noise generationprocess inside the pipe. There aretimes when this is the area of interest,but the noise levels on the outside ofthe pipe are the prime requirement.The method must account for thechange in the noise as the referencelocation moves from inside the pipe tooutside the pipe. The pipe wall hasphysical characteristics, due to its ma-terial, size, and shape, that definehow well the noise will transmitthrough the pipe. The fluid-bornenoise inside the pipe must interactwith the inside pipe wall to cause thepipe wall to vibrate, then the vibrationmust transmit through the pipe wall tothe outside pipe wall, and there theoutside pipe wall must interact withthe atmosphere to generate soundwaves. These three steps of noisetransmission are dependent on thenoise frequency. The method repre-
Chapter 5. Control Valve Selection
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sents the frequency of the valve noiseby determining the peak frequency ofthe valve noise spectrum. The methodalso determines the pipe transmissionloss as a function of frequency. Themethod then compares the internalnoise spectrum and the transmission-loss spectrum to determine how muchthe external sound pressure will beattenuated by the pipe wall.
5—Account for distance and calcu-late the sound pressure level at theobserver’s location. Step 4 deliversthe external sound pressure level atthe outside surface of the pipe wall.Again, basic acoustic theory is appliedto calculate the sound pressure levelat the observer’s location. Sound pow-er is constant for any given situation,but the associated sound pressurelevel varies with the area the power isspread over. As the observer movesfarther away from the pipe wall, thetotal area the sound power is spreadover increases. This causes thesound pressure level to decrease.
Hydrodynamic
Noticeable hydrodynamic noise isusually associated with cavitation. Thetraditional description of the sound isas rocks flowing inside the pipe. Thisassociation of hydrodynamic noisewith cavitation is reflected in the vari-ous prediction methods availabletoday. The methods account for onenoise characteristic for liquids in non-choked flow situations and anothercharacteristic in choked, cavitatingflow situations.
There are a variety of situations wherethe fluid is a two-phase mixture.These include liquid-gas two-phasefluids at the inlet of the valve, flashingfluids, and fluids that demonstrate out-gassing due to throttling. Noise pre-diction methods for these cases arenot yet well established. Test resultsand field surveys of installed multi-phase systems indicate these noiselevels do not contribute to overall
plant noise levels or exceed workerexposure levels.
Noise ControlIn closed systems (not vented to at-mosphere), any noise produced in theprocess becomes airborne only bytransmission through the valves andadjacent piping that contain the flow-stream. The sound field in the flow-stream forces these solid boundariesto vibrate. The vibrations cause distur-bances in the ambient atmospherethat are propagated as sound waves.
Noise control employs either sourcetreatment, path treatment, or both.Source treatment, preventing or atte-nuating noise at its source, is the mostdesirable approach, if economicallyand physically feasible.
Recommended cage-style sourcetreatment approaches are depicted infigure 5-8. The upper view shows acage with many narrow parallel slotsdesigned to minimize turbulence andprovide a favorable velocity distribu-tion in the expansion area. This eco-nomical approach to quiet valve de-sign can provide 15 to 20 dBA noisereduction with little or no decrease inflow capacity.
The lower view in figure 5-8 shows atwo-stage, cage-style trim designedfor optimum noise attenuation wherepressure drop ratios (�P/P1) are high.
To obtain the desired results, restric-tions must be sized and spaced in theprimary cage wall so that the noisegenerated by jet interaction is notgreater than the summation of thenoise generated by the individual jets.
This trim design can reduce the valvenoise by as much as 30 dBA. The fi-nal design shown uses a combinationof several noise reduction strategiesto reduce valve noise up to 40 dBA.Those strategies are:
� Unique passage shape reducesthe conversion of total stream powergenerated by the valve into noisepower.
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Figure 5-8. Valve Trim Design forReducing Aerodynamic Noise
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� Multistage pressure reductiondivides the stream power betweenstages and further reduces the acous-tic conversion efficiency.
� Frequency spectrum shifting re-duces acoustic energy in the audiblerange by capitalizing on the transmis-sion loss of the piping.
� Exit jet independence is main-tained to avoid noise regeneration dueto jet coalescence.
� Velocity management is accom-plished with expanding areas to ac-commodate the expanding gas.
� Complementary body designsprevent flow impingement on the bodywall and secondary noise sources.
For control valve applications operat-ing at high pressure ratios (�P/P1 >0.8) the series restriction approach,
splitting the total pressure drop be-tween the control valve and a fixed re-striction (diffuser) downstream of thevalve can be effective in minimizingnoise. To optimize the effectiveness ofa diffuser, it must be designed (specialshape and sizing) for each giveninstallation so that the noise levelsgenerated by the valve and diffuserare equal. Figure 5-9 shows a typicalinstallation.
Control systems venting to atmo-sphere are generally very noisy be-cause of the high pressure ratios andhigh exit velocities involved. Dividingthe total pressure drop between theactual vent and an upstream controlvalve, by means of a vent diffuser,quiets both the valve and the vent. Aproperly sized vent diffuser and valvecombination, such as that shown infigure 5-10, can reduce the overallsystem noise level as much as 40dBA.
Source treatment for noise problemsassociated with control valves han-dling liquid is directed primarily ateliminating or minimizing cavitation.Because flow conditions that will pro-duce cavitation can be accurately pre-dicted, valve noise resulting from cavi-tation can be eliminated by applicationof appropriate limits to the serviceconditions at the valve by use ofbreak-down orifices, valves in series,etc. Another approach to source treat-ment is using special valve trim thatuses the series restriction concept toeliminate cavitation as shown in figure5-11.
A second approach to noise control isthat of path treatment. The fluidstream is an excellent noise transmis-sion path. Path treatment consists ofincreasing the impedance of the trans-mission path to reduce the acousticenergy communicated to the receiver.
Dissipation of acoustic energy by useof acoustical absorbent materials isone of the most effective methods ofpath treatment. Whenever possiblethe acoustical material should be lo-
Chapter 5. Control Valve Selection
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Figure 5-9. Valve and Inline Diffuser Combination
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Figure 5-10. Valve and VentDiffuser Combination
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cated in the flow stream either at orimmediately downstream of the noisesource. In gas systems, inline silenc-ers effectively dissipate the noisewithin the fluid stream and attenuatethe noise level transmitted to the solid
Figure 5-11. Special ValveDesign to Eliminate Cavita-
tion
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boundaries. Where high mass flowrates and/or high pressure ratiosacross the valve exist, inline silencers,such as that shown in figure 5-12, areoften the most realistic and economi-cal approach to noise control. Use of
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Figure 5-12. Typical In-Line Silencer
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absorption-type inline silencers canprovide almost any degree of attenua-tion desired. However, economic con-siderations generally limit the insertionloss to approximately 25 dBA.
Noise that cannot be eliminated withinthe boundaries of the flow streammust be eliminated by external treat-ment. This approach to the abatementof control valve noise suggests theuse of heavy walled piping, acousticalinsulation of the exposed solid bound-aries of the fluid stream, use of insu-lated boxes, buildings, etc., to isolatethe noise source.
Path treatment such as heavy wallpipe or external acoustical insulationcan be an economical and effectivetechnique for localized noise abate-ment. However, noise is propagatedfor long distances via the fluid streamand the effectiveness of the heavywall pipe or external insulation endswhere the treatment ends.
Noise SummaryThe amount of noise that will be gen-erated by a proposed control valveinstallation can be quickly and reason-ably predicted by use of industry stan-dard methods. These methods areavailable in computer software forease of use. Such sizing and noiseprediction tools help in the properselection of noise reduction equip-ment such as shown in figures 5-13and 5-14. Process facility require-ments for low environmental impactwill continue to drive the need forquieter control valves. The predictiontechnologies and valve designs that
Figure 5-13. Globe Style Valvewith Noise Abatement Cage for
Aerodynamic Flow
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Figure 5-14. Ball Style Valvewith Attenuator to Reduce
Hydrodynamic Noise
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deliver this are always being im-proved. For the latest in either equip-ment or prediction technology, contactthe valve manufacturer’s representa-tive.
Chapter 5. Control Valve Selection
144
Figure 5−15. Application Guidelines Chart for 100 PPM Service
E0936/IL
(KVSP 400)
ENVIRO−SEAL DUPLEX
ÍÍÍÍÍÍ
ÍÍÍ KALREZWITHZYMAXX(KVSP500)
Figure 5−16. Application Guidelines Chart for Non−Environmental Service
e0937/IL
KALREZ withPTFE (KVSP400)
ENVIRO-SEAL�PTFE and DUPLEX
Packing SelectionThe following tables and figures 5-15and 5-16 offer packing selection
guidelines for sliding-stem and rotaryvalves.
Ch
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Packing Selection Guidelines for Sliding-Stem Valves
Packing System
Maximum Pressure andTemperature Limits for
100 PPM Service(1)
Application Guideline forNonenvironmental
Service(1)
SealPerformance
Index
ServiceLife
Index
PackingFriction(2)
Metric Imperial Metric Imperial
Single PTFE V-Ring20.7 bar
−18 to 93�C
300 psi
0 to 200�F−46 to 232�C −50 to 450�F Better Long Very low
Double PTFE V-Ring − − − − − − −46 to 232�C −50 to 450�F Better Long Low
ENVIRO-SEAL PTFE −46 to 232�C −50 to 450�F −46 to 232�C −50 to 450�F Best Very long Low
ENVIRO-SEAL Duplex51.7 bar
−46 to 232�C
750 psi
−50 to 450�F−46 to 232�C −50 to 450�F Best Very long Low
KALREZ� with PTFE(KVSP 400)(3)
24.1 bar4 to 204
350 psig40 to 400�F
−40 to 204�C −40 to 400�F Best Long Low
KALREZ with ZYMAXX�(KVSP 500)(3)
24.1 bar4 to 260�C
350 psig40 to 500�F
−40 to 260�C −40 to 500�F Best Long Low
ENVIRO-SEAL Graphite ULF103 bar−7 to 315�C
1500 psi20 to 600�F
207 bar−198 to 371�C
3000 psi−325 to 700�F
Best Very long Medium
HIGH-SEAL Graphite ULF103 bar−7 to 315�C
1500 psi20 to 600�F
290 bar(4)
−198 to 538�C4200 psi(4)
−325 to 1000�FBest Very long Medium
Graphite Composite / HIGH-SEALGraphite
− − − − − −290 bar(4)
−198 to 649�C(5)4200 psi(4)
−325 to 1200�F(5) Better Very long Very high
Braided Graphite Filament − − − − − −290 bar−198 to 538�C(5)
4200 psi−325 to 1000�F(5) Good Moderate High
Graphite ULF − − − − − −290 bar−198 to 538�C
4200 psi−325 to 1000�F
Better Very long Medium
1. The values shown are only guidelines. These guidelines can be exceeded, but shortened packing life or increased leakage might result. The temperature ratings apply to the actual packingtemperature, not to the process temperature.2. See manufacturer for actual friction values.3. The KALREZ pressure/temperature limits referenced in this bulletin are for Fisher valve applications only. DuPont Dow Elastomers LLC may claim higher limits.4. Except for the 9.5 mm (3/8 inch) stem, 110 bar (1600 psi).5. Except for oxidizing service, −198 to 371�C (−325 to 700�F).
Ch
apter 5. C
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Packing Selection Guidelines for Rotary Valves
PACKING SYSTEM
MAXIMUM PRESSURE ANDTEMPERATURE LIMITS FOR
500 PPM SERVICE(1)
APPLICATION GUIDELINE FORNONENVIRONMENTAL SERVICE(1)
SEALPERFORMANCE
INDEX
SERVICELIFE
INDEX
PACKINGFRICTION
Metric Customary U.S. Metric Customary U.S.
Single PTFE V-Ring− − −− − −
− − −− − −
103 bar
−46 to 232�C
1500 psig
−50 to 450�FBetter Long Very low
ENVIRO-SEAL PTFE103 bar
−46 to 232�C
1500 psig
−50 to 450�F
103 bar
−46 to 232�C
1500 psig
−50 to 450�FSuperior Very long Low
KALREZ� with PTFE (KVSP400)
24.1 bar
4 to 204�C350 psig40 to 400�F
51 bar−40 to 204�C
750 psig−40 to 400�F
Superior Long Very low
KALREZ with ZYMAXX�(KVSP 500)
24.1 bar
4 to 260�C350 psig40 to 500�F
51 bar−40 to 260�C
750 psig−40 to 500�F
Superior Long Very low
ENVIRO-SEAL Graphite103 bar−18 to 315�C
1500 psig20 to 600�F
207 bar−198 to 371�C
3000 psig−325 to 700�F
Superior Very long Moderate
Graphite Ribbon− − −− − −
− − −− − −
103 bar−198 to 538�C(2)
1500 psig−325 to 1000�F(2) Acceptable Acceptable High
1. The values shown are only guidelines. These guidelines can be exceeded, but shortened packing life or increased leakage might result. The temperature ratings apply to the actualpacking temperature, not to the process temperature.2. Except for oxidizing service, −198 to 371�C (−325 to 700�F).
147
Chapter 6
Special Control Valves
As discussed in previous chapters,standard control valves can handle awide range of control applications.The range of standard applicationscan be defined as being encom-passed by: atmospheric pressure and6000 psig (414 bar), −150�F (−101�C)and 450�F (232�C), flow coefficientCv values of 1.0 and 25000, and thelimits imposed by common industrialstandards. Certainly, corrosivenessand viscosity of the fluid, leakagerates, and many other factors demandconsideration even for standard ap-plications. Perhaps the need for care-ful consideration of valve selection be-comes more critical for applicationsoutside the standard limits mentionedabove.
This chapter discusses some specialapplications and control valve modifi-cations useful in controlling them, de-signs and materials for severe ser-
vice, and test requirements useful forcontrol valves used in nuclear powerplant service.
High Capacity ControlValvesGenerally, globe-style valves largerthan 12-inch, ball valves over 24-inch,and high performance butterfly valveslarger than 48-inch fall in the specialvalve category. As valve sizes in-crease arithmetically, static pressureloads at shutoff increase geometrical-ly. Consequently, shaft strength, bear-ing loads, unbalance forces, andavailable actuator thrust all becomemore significant with increasing valvesize. Normally maximum allowablepressure drop is reduced on largevalves to keep design and actuatorrequirements within reasonable limits.Even with lowered working pressureratings, the flow capacity of some
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Figure 6-1. Large Flow Valve Body forNoise Attenuation Service
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large-flow valves remains tremen-dous.
Noise levels must be carefully consid-ered in all large-flow installations be-cause sound pressure levels increasein direct proportion to flow magnitude.To keep valve-originated noise withintolerable limits, large cast or fabri-cated valve body designs (figure 6-1)have been developed. These bodies,normally cage-style construction, useunusually long valve plug travel, agreat number of small flow openingsthrough the wall of the cage and anexpanded outlet line connection tominimize noise output and reducefluid velocity.
Naturally, actuator requirements aresevere, and long-stroke, double actingpneumatic pistons are typically speci-fied for large-flow applications. Thephysical size and weight of the valveand actuator components complicateinstallation and maintenance proce-dures. Installation of the valve body
assembly into the pipeline and remov-al and replacement of major trim partsrequire heavy-duty hoists. Mainte-nance personnel must follow themanufacturers’ instruction manualsclosely to minimize risk of injury.
Low Flow Control ValvesMany applications exist in laboratoriesand pilot plants in addition to the gen-eral processing industries where con-trol of extremely low flow rates is re-quired. These applications arecommonly handled in one of twoways. First, special trims are oftenavailable in standard control valvebodies. The special trim is typicallymade up of a seat ring and valve plugthat have been designed and ma-chined to very close tolerances to al-low accurate control of very smallflows. These types of constructionscan often handle Cv’s as low as 0.03.Using these special trims in standardcontrol valves provides economy byreducing the need for spare parts in-ventory for special valves and actua-tors. Using this approach also makesfuture flow expansions easy by simplyreplacing the trim components in thestandard control valve body.
Control valves specifically designedfor very low flow rates (figure 6-2) alsohandle these applications. Thesevalves often handle Cv’s as low as0.000001. In addition to the very lowflows, these specialty control valvesare compact and light weight becausethey are often used in laboratory envi-ronments where very light schedulepiping/tubing is used. These types ofcontrol valves are specially designedfor the accurate control of very lowflowing liquid or gaseous fluid applica-tions.
High-Temperature ControlValvesControl valves for service at tempera-tures above 450°F (232°C) must bedesigned and specified with the tem-perature conditions in mind. At ele-
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Figure 6-2. Special Control Valve Designed for Very Low Flow Rates
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vated temperatures, such as may beencountered in boiler feedwater sys-tems and superheater bypass sys-tems, the standard materials of controlvalve construction might be inade-quate. For instance, plastics, elasto-mers, and standard gaskets generallyprove unsuitable and must be re-placed by more durable materials.Metal-to-metal seating materials arealways used. Semi-metallic or lami-nated flexible graphite packing materi-als are commonly used, andspiral-wound stainless steel and flex-ible graphite gaskets are necessary.
Cr-Mo steels are often used for thevalve body castings for temperaturesabove 1000°F (538°C). ASTM A217Grade WC9 is used up to 1100°F(593°C). For temperatures on up to1500°F (816°C) the material usuallyselected is ASTM A351 Grade CF8M,Type 316 stainless steel. For tempera-tures between 1000°F (538°C) and1500°F (816°C), the carbon contentmust be controlled to the upper end ofthe range, 0.04 to 0.08%. The9%Cr−1%Mo−V materials, such asASTM A217 grade C12a castings andASTM A182 grade F91 forgings are
used at temperatures up to 1200°F(650°C).
Extension bonnets help protect pack-ing box parts from extremely hightemperatures. Typical trim materialsinclude cobalt based Alloy 6, 316 withalloy 6 hardfacing and nitrided 422SST.
Cryogenic Service ValvesCryogenics is the science dealing withmaterials and processes at tempera-tures below minus 150�F (−101�C).For control valve applications in cryo-genic services, many of the same is-sues need consideration as with high−temperature control valves. Plasticand elastomeric components oftencease to function appropriately at tem-peratures below 0�F (−18�C). Inthese temperature ranges, compo-nents such as packing and plug sealsrequire special consideration. For plugseals, a standard soft seal will be-come very hard and less pliable thusnot providing the shut-off requiredfrom a soft seat. Special elastomershave been applied in these tempera-
Chapter 6. Special Control Valves
150
Figure 6-3. Typical Extension Bonnet
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tures but require special loading toachieve a tight seal.
Packing is a concern in cryogenic ap-plications because of the frost thatmay form on valves in cryogenic ap-plications. Moisture from the atmo-sphere condensates on colder sur-faces and where the temperature ofthe surface is below freezing, themoisture will freeze into a layer offrost. As this frost and ice forms onthe bonnet and stem areas of controlvalves and as the stem is stroked bythe actuator, the layer of frost on thestem is drawn through the packingcausing tears and thus loss of seal.The solution is to use extension bon-nets (figure 6-3) which allow the pack-ing box area of the control valve to bewarmed by ambient temperatures,thus preventing frost from forming onthe stem and packing box areas. Thelength of the extension bonnet de-pends on the application temperatureand insulation requirements. The cold-er the application, the longer the ex-tension bonnet required.
Figure 6-4. Inherent ValveCharacteristics
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Materials of construction for cryogenicapplications are generally CF8M bodyand bonnet material with 300 seriesstainless steel trim material. In flash-ing applications, hard facing might berequired to combat erosion.
CustomizedCharacteristics and NoiseAbatement Trims
Although control valve characteristicsused in standard control valves (figure6-4) meet the requirements of mostapplications, often custom character-istics are needed for a given applica-tion. In these instances, special trimdesigns can be manufactured thatmeet these requirements. For con-toured plugs, the design of the plug tipcan be modified so that as the plug ismoved through its travel range, theunobstructed flow area changes insize to allow for the generation of thespecific flow characteristic. Likewise,cages can be redesigned to meet spe-cific characteristics as well. This is es-pecially common in noise abatementtype trims where a high level of noiseabatement may be required at lowflow rates but much lower abatementlevels are required for the higher flowrate conditions.
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Control Valves for NuclearService in the USASince 1970, U.S. manufacturers andsuppliers of components for nuclearpower plants have been subject to therequirements of Appendix B, Title 10,Part 50 of the Code of Federal Regu-lations entitled Quality Assurance Cri-teria for Nuclear Power Plants andFuel Reprocessing Plants. The U.S.Nuclear Regulatory Commission en-forces this regulation. Ultimate re-sponsibility of proof of compliance toAppendix B rests with the owner ofthe plant, who must in turn rely on themanufacturers of various plant com-ponents to provide documented evi-dence that the components weremanufactured, inspected, and testedby proven techniques performed byqualified personnel according to docu-mented procedures.
In keeping with the requirements ofthe Code of Federal Regulations,most nuclear power plant componentsare specified in accordance with Sec-tion III of the ASME Boiler and Pres-sure Vessel Code entitled NuclearPower Plant Components. All aspectsof the manufacturing process must bedocumented in a quality control manu-al and audited and certified by ASMEbefore actual manufacture of the com-ponents. All subsequent manufactur-ing materials and operations are to bechecked by an authorized inspector.All valves manufactured in accor-dance with Section III requirementsreceive an ASME code nameplateand an N stamp symbolizing accept-ability for service in nuclear powerplant applications.
Section III does not apply to parts notassociated with the pressure−retain-ing function, to actuators and acces-sories unless they are pressure retain-ing parts, to deterioration of valvecomponents due to radiation, corro-sion, erosion, seismic or environmen-tal qualifications, or to cleaning, paint-ing, or packaging requirements.However, customer specifications nor-
mally cover these areas. Section IIIdoes apply to materials used for pres-sure retaining parts, to design criteria,to fabrication procedures, to non-de-structive test procedures for pressureretaining parts, to hydrostatic testing,and to marking and stamping proce-dures. ASME Section III is revised bymeans of semi-annual addenda,which may be used after date of is-sue, and which become mandatory sixmonths after date of issue.
Valves Subject to SulfideStress CrackingNACE International is a technical soci-ety concerned with corrosion and cor-rosion-related issues. NACE is re-sponsible for a large number ofstandards, but by far the most influen-tial and well known is MR0175, for-merly entitled “Sulfide Stress CrackingResistant Metallic Materials for OilfieldEquipment”. MR0175 was issued byNACE in1975 to provide guidelines forthe selection of materials that are re-sistant to failure in hydrogen sulfide−containing oil and gas production en-vironments. MR0175 has been sowidely referenced that, throughout theprocess industry, the term “NACE”has become nearly synonymous with“MR0175”. However, the situationchanged in 2003.
MR0175 was modified significantly ina 2003 revision to cover chloridestress corrosion cracking in addition tosulfide stress cracking. Then, in late2003, the document was reformattedand released as a joint NACE/ISOdocument called NACE MR0175/ISO15156, “Petroleum and Natural GasIndustries − Materials for Use in H2S−Containing Environments in Oil andGas Production”.
In April 2003, NACE also released anew standard, MR0103, which is en-titled, “Materials Resistant to SulfideStress Cracking in Corrosive Petro-leum Refining Environments.” Thisstandard is essentially the refining in-dustry’s “NACE MR0175”. MR0103
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only addresses sulfide stress crack-ing, and as such is similar in many re-spects to the pre-2003 revisions ofMR0175. Use of the MR0103 stan-dard in the refining industry is acceler-ating.
Note that compliance with certain revi-sions of NACE MR0175 or NACEMR0175/ISO 15156 is mandated bystatute in some states and regions inthe U.S.A. At this time, NACEMR0103 is not mandated by any gov-erning bodies.
Pre-2003 Revisions of MR0175
The following statements, althoughbased on information and require-ments in the pre-2003 revisions ofMR0175, cannot be presented in thedetail furnished in the actual standardand do not guarantee suitability forany given material in hydrogen sul-fide-containing sour environments.The reader is urged to refer to the ac-tual standard before selecting controlvalves for sour service.
� Most ferrous metals can becomesusceptible to sulfide stress cracking(SSC) due to hardening by heat treat-ment and/or cold work. Conversely,many ferrous metals can be heattreated to improve resistance to SSC.
� Carbon and low-alloy steelsmust be properly heat treated to pro-vide resistance to SSC. A maximumhardness limit of HRC 22 applies tocarbon and low-alloy steels.
� Austenitic stainless steels aremost resistant to SSC in the annealedcondition; some specific grades andconditions of stainless steels are ac-ceptable up to 35 HRC.
� Copper-base alloys are inherent-ly resistant to SSC, but are generallynot used in critical parts of a valvewithout the approval of the purchaserdue to concerns about general corro-sion.
� Nickel alloys generally providethe best resistance to SSC. Someprecipitation-hardenable nickel alloysare acceptable for use in applicationsrequiring high strength and/or hard-ness up to 40 HRC.
� Chromium, nickel, and othertypes of plating offer no protectionagainst SSC. Their use is allowed insour applications for wear resistance,but they cannot be used in an attemptto protect a non-resistant base materi-al from SSC.
� Weld repairs and fabricationwelds on carbon and low-alloy steelsmust be properly processed to ensurethat they meet the 22 HRC maximumhardness requirement in the basemetal, heat-affected zone (HAZ), andweld deposit. Alloy steels requirepost-weld heat treatment, and post−weld heat treatment is generally usedfor carbon steels as well.
� Conventional identificationstamping is permissible in low stressareas, such as on the outside diame-ter of line flanges. Low-stress identifi-cation stamping must be used in otherareas.
� The standard precludes usingASTM A193 Grade B7 bolting for ap-plications that are considered “ex-posed”. Use of SSC-resistant boltingmaterials (such as ASTM A193Grade B7M) sometimes necessitatesto derating of valves designed origi-nally to use B7 bolting. For example,in a Class 600 globe valve, 17-4PHH1150 DBL bolting can be used toavoid derating.
NACE MR0175/ISO 15156NACE MR0175/ISO 15156 introducedsignificant changes to the standard.However, many end users continue tospecify NACE MR0175-2002, feelingthat it adequately meets their needs inproviding good service life. The mostsignificant changes in NACEMR0175/ISO 15156 include:
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� The 17-4PH H1150 DBL boltingthat was previously used for full−ratedexposed bolting in a Class 600 globevalve is no longer allowed.
� The revision addresses both sul-fide stress cracking and chloridestress corrosion cracking. Prior ver-sions simply listed most materials asacceptable or unacceptable. Becauseits scope was expanded to cover chlo-ride stress corrosion cracking, thenew standard lists all corrosion-resist-ant alloys as acceptable within limits,referred to as “environmental limits orenvironmental restrictions”. Theseare typically expressed in terms ofH2S partial pressure, maximum tem-perature, ppm chlorides, and the pres-ence of free sulfur.
� 316 usage is still allowed but un-der very limited environmental condi-tions. The impact, if strictly followed,is that this material will find very littleuse.
� The standard applies only to pe-troleum production, drilling, gatheringand flow line equipment, and fieldprocessing facilities to be used in H2Sbearing hydrocarbon service. It doesnot apply to refineries.
� There is clear responsibilityplaced on the buyer to specify the cor-rect materials. The manufacturer isresponsible for meeting the metallurgi-cal requirements of MR0175/ISO15156.
NACE MR0103
As mentioned, NACE MR0103 is simi-lar in many respects to the pre-2003revisions of NACE MR0175. Follow-ing are the some major differences:
� MR0103 utilizes different, refin-ery-based definitions for what consti-tutes a sour environment. The user isresponsible for imposing the require-ments of MR0103 when they are ap-plicable.
� The 2002 and older revisions ofMR0175 included environmental re-strictions on a few materials that werecontinued in the latter editions.MR0103 only deals with sulfide stresscracking. It does not impose environ-mental limits on any materials. Mate-rials are either acceptable or not.
� Carbon steel base materials thatare classified as P-No. 1, group 1 or 2steels in the ASME Boiler and Pres-sure Vessel Code are acceptable perMR0103 without base metal hardnessrequirements. P-No. 1 groups 1 and 2include WCC and LCC castings, A105forgings, A516 Grade 70 plate, andthe other common carbon steel pres-sure vessel materials.
� MR0103 imposes welding con-trols on carbon steels that are morerigorous than those imposed byMR0175-2002. MR0103 requires thatP-No. 1 carbon steels be welded peranother NACE document calledRP0472 “Methods and Controls toPrevent In-Service EnvironmentalCracking of Carbon Steel Weldmentsin Corrosive Petroleum Refining Envi-ronments”. RP0472 imposes controlsthat ensure both the weld deposit andheat affected zone (HAZ) in a weld-ment will be soft enough to resist sul-fide stress cracking. RP0472 invokesactual hardness testing of weld de-posits in production, although hard-ness testing is waived if certain weld-ing process/filler materialcombinations are employed. HAZhardness may be controlled by eitherpost-weld heat treatment (PWHT) orby base material chemistry restrictionssuch as imposing a maximum carbonequivalent (CE).
� Like the 2003 and later revisionsof MR0175, MR0103 does not allowthe use of S17400 double H1150 ma-terial for bolting. This means that the17-4PH H1150 DBL bolting that waspreviously used for full-rated exposedbolting in a Class 600 valve is no lon-ger allowed.
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155
Chapter 7
Steam Conditioning Valves
Steam conditioning valves includethose in desuperheating, steam condi-tioning, and turbine bypass systems,covered in this chapter.
UnderstandingDesuperheatingSuperheated steam provides an ex-cellent source of energy for mechani-cal power generation. However, inmany instances, steam at greatly re-duced temperatures, near saturation,proves a more desirable commodity.This is the case for most heat−transferapplications. Precise temperaturecontrol is needed to improve heatingefficiency; eliminate unintentional su-perheat in throttling processes; or toprotect downstream product and/orequipment from heat related damage.One method to reduce temperature isthe installation of a desuperheater.
A desuperheater injects a controlled,predetermined amount of water into asteam flow to lower the temperature ofthe steam. To achieve this efficiently,the desuperheater must be designedand selected correctly for the applica-tion. Although it can appear simplisticin design, the desuperheater must in-tegrate with a wide variety of complexthermal and flow dynamic variables tobe effective. The control of the waterquantity, and thus the steam tempera-ture, uses a temperature control loop.This loop includes a downstream tem-perature sensing device, a controllerto interpret the measured temperaturerelative to the desired set point, andthe transmission of a proportional sig-nal to a water controlling valve/actua-tor assembly to meter the requiredquantity of water.
The success or failure of a particulardesuperheater installation rests on anumber of physical, thermal, and geo-
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Figure 7-1. Desuperheater Installations
B2567/IL
metric factors. Some of these are ob-vious and some obscure, but all ofthem have a varying impact on theperformance of the equipment and thesystem in which it is installed.
The first, and probably the most im-portant factor for efficient desuper-heater operation, is to select the cor-rect design for the respectiveapplication. Desuperheaters come inall shapes and sizes and use variousenergy transfer and mechanical tech-niques to achieve the desired perfor-mance within the limits of the systemenvironment. Another section detailsthe differences in the types of desup-erheaters available and expected per-formance.
Technical Aspects ofDesuperheating
Some of the physical parameters thataffect the performance of a desuper-heating system include:
� Installation orientation
� Spraywater temperature
� Spraywater quantity
� Pipeline size
� Steam velocity
� Equipment versus system turn-down
Installation orientation is an oftenoverlooked, but critical factor in theperformance of the system. Correctplacement of the desuperheater canhave a greater impact on the opera-tion than the style of the unit itself. Formost units, the optimum orientation isin a vertical pipeline with the flow di-rection up. This is contrary to mostinstallations seen in industry today.Other orientation factors include pipefittings, elbows, and any other type ofpipeline obstruction that exists down-stream of the water injection point.Figure 7-1 illustrates variations in theinstallation of a desuperheater.
Spraywater temperature can have asignificant impact on desuperheaterperformance. Although it goes againstlogical convention, high−temperaturewater is better for cooling. As thespraywater temperature increases,flow and thermal characteristics im-prove and impact the following:
� Surface tension
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Figure 7-2. Spray PenetrationB2568/IL
� Drop size distribution
� Latent heat of vaporization
� Vaporization rate
Improvements in all these areas, as aresult of increased spraywater tem-perature, improves the overall perfor-mance of the system.
The quantity of water to be injectedwill have a directly proportional effecton the time for vaporization. The heattransfer process is time dependentand, thus, the quantity of spraywaterwill affect the time for complete vapor-ization and thermal stability.
To determine the spraywater required(Qw) as a function of inlet steam flow(Q1), perform a simple heat balanceusing the following equation:
Qw(mass) � Q1 * �H1 � H2H2 � Hw
�
Where Q is the mass flow in PPH andH is the individual enthalpy values atthe inlet, outlet, and spraywater.
When the calculation is performed asa function of outlet steam flow (Q2),that is, the combination of inlet steamflow and desuperheating spraywater,use the following equation:
Qw(mass) � Q2 * �H1 � H2Hw � H1
�
To perform a basic Cv calculation forinitial desuperheater sizing, it is re-quired that the resultant Qw(mass) isconverted to Qw(volumetric). Whenusing English units the conversion isdone as follows:
Qw(volumetric) �Qw(mass) * 0.1247
pw
Qw(volumetric) is in GPM and ρw isthe density of the spraywater in Lbm/Ft3. Based on this conversion, the siz-ing can be completed with the follow-ing Cv calculation for each set ofconditions:
Cv � Qw(volumetric) * SG�Pdsh
�
Where SG is the specific gravity of thespraywater and ∆Pdsh is the pressuredifferential across the proposed de-superheater.
When designing a new desuperheaterinstallation, another concern for prop-er system performance is the pipelinesize. As the line size gets larger, moreattention must be paid to the penetra-tion velocity of the spray and the cov-erage in the flow stream (figure 7-2).
Some single-point, injection type de-superheaters have insufficient nozzleenergy to disperse throughout the en-tire cross sectional flow area of thepipeline. As a result, the spray patterncollapses and thermal stratification oc-curs, that is, a sub-cooled center corethat is shrouded with superheated
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steam. This condition is normally elim-inated after the flow stream has un-dergone several piping directionalchanges, but this is not always pos-sible within the limits of the controlsystem or process. Proper placementof high-energy, multi-nozzle units inthe larger pipelines normally preventsthe formation of thermal stratification.
The maximum and minimum velocityof the steam has a direct relationshipon the successful mixing of the water.The velocity directly affects the resi-dence time available for the water tomix with the steam. When the maxi-mum velocity is too high, there poten-tially is not enough time for the waterto mix before it encounters a pipingobstruction such as an elbow or tee.Ideal maximum velocity usuallyranges from 150-250 feet per second(46−76 meters per second). When theminimum velocity is too low, turbu-lence is reduced and then the waterdroplets tend to fall out of suspensionin the steam. As a rule, the minimumsteam velocity in which water can re-main suspended is approximately 30feet per second (9 meters per sec-ond). For applications with lower ve-locities, proper mixing may beachieved with desuperheaters that of-fer a venturi or atomizing steam.
One of the most over-used and mis-understood concepts in the area ofdesuperheating is turndown. Whenapplied to a final control element,such as a valve, turndown is a simpleratio of the maximum to the minimumcontrollable flow rate. Turndown issometimes used interchangeably withrangeability. However, the exactmeaning differs considerably when itcomes to actual performance compar-isons.
A desuperheater is not a final controlelement, and as such, its performanceis directly linked to its system environ-ment. The actual system turndown ismore a function of the system param-eters rather than based on the equip-ment’s empirical flow variations. Once
this is understood, it is obvious that agood desuperheater cannot overcomethe failings of a poor system. Theymust be evaluated on their own meritsand weighted accordingly.
Due to improved nozzle designtechnology, pipe liners are rarely re-quired. Depending on the particulatequality of the water source, in-linestrainers may be required.
The previous calculations and recom-mendations provide the necessary in-formation to select the proper desup-erheater design and size. Thisselection should be based on a varietyof application considerations such as:
� Minimum to maximum load re-quirement rangeability
� Minimum steam velocity
� Straight pipe length and temper-ature sensor distance after the desup-erheater
� Steam pipe line size and
� Pressure differential betweenwater and steam
Typical DesuperheaterDesigns
Fixed Geometry Nozzle DesignThe fixed geometry nozzle design (fig-ure 7-3) is a simple mechanically at-omized desuperheater with single ormultiple fixed geometry spray nozzles.It is intended for applications withnearly constant load changes (range-ability up to 5:1) and is capable ofproper atomization in steam flow ve-locities as low as 14 feet per secondunder optimum conditions. Standardinstallation of this type of unit isthrough a flanged branch connectiontee on a 6-inch or larger steam pipeline. This design is usually not avail-able for large Cv requirements. Thisunit requires an external water controlvalve to meter water flow based on asignal from a temperature sensor inthe downstream steam line.
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Figure 7-3. Fixed GeometryNozzle Design
W7102/IL
Figure 7-4. Variable GeometryNozzle Design
W6310-1/IL
Variable Geometry NozzleDesign
The variable geometry nozzle design(figure 7-4) is also a simple mechani-cally atomized desuperheater, but itemploys one or more variable geome-
try, back pressure activated spraynozzles. Due to the variable geometry,this unit can handle applications re-quiring control over moderate loadchanges (rangeability up to 20:1) andis capable of proper atomization insteam flow velocities as low as 14 feetper second under optimum conditions.Standard installation of this type ofunit is through a flanged branch con-nection tee on an 8-inch or largersteam pipe line. These units are avail-able for large Cv requirements. Thisdesign requires an external water con-trol valve to meter water flow basedon a signal from a temperature sensorin the downstream steam line.
Self-Contained Design
The self-contained design (figure 7-5)is also mechanically atomized withone or more variable geometry, backpressure activated spray nozzles. Asa special feature, this unit incorpo-rates a water flow control element thatperforms the function normally pro-vided by an external water controlvalve. This control element has a plugthat moves inside a control cage bymeans of an actuator, which receivesa signal from a temperature sensor inthe downstream steam line. The waterflow then passes to the variable ge-ometry nozzle(s) and is atomized as itenters the steam pipe line. Because ofthe close coordination of the intrinsiccontrol element and the variable ge-ometry nozzle(s), this unit can handleapplications requiring control overmoderate to high load changes(rangeability up to 25:1). It offers prop-er atomization in steam flow velocitiesas low as 14 feet per second underoptimum conditions. Standard installa-tion of this type of unit is through aflanged branch connection tee on an8-inch or larger steam pipe line.These are available for moderate Cvrequirements.
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Figure 7-5. Self-Contained Design
W6982-1 / IL
Figure 7-6. Steam Assisted Design
W6311/IL
Steam Atomized DesignThe steam atomized design (figure7-6) incorporates the use of high-pres-sure steam for rapid and complete at-omization of the spraywater. This isespecially useful in steam pipe linesthat have low steam velocity. The at-
omizing steam, usually twice the mainsteam line pressure or higher, en-counters the water in the spray nozzlechamber where the energy of the ex-panding atomizing steam is used toatomize the water into very smalldroplets. These smaller droplets allowfor faster conversion to steam andpermit the water to remain suspendedin a low steam velocity flow, therebyallowing complete vaporization to oc-cur. The steam atomized design,therefore, can properly mix water intosteam flow velocities as low asapproximately 4 feet per second (1.2meters per second) under optimumconditions. This design handles ap-plications requiring very high loadchanges (rangeability up to 50:1).Standard installation of this type ofunit is through a flanged branch con-nection tee on an 8-inch or largersteam pipe line. This design is avail-able for moderate Cv requirements. Itrequires an external water controlvalve to meter water flow based on asignal from a temperature sensor inthe downstream steam line. This sys-
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Figure 7-7. Geometry-Assisted Wafer Design
W6313-1/IL
tem also requires a separate on/offvalve for the atomizing steam supply.
Geometry-Assisted WaferDesign
The geometry-assisted wafer design(figure 7-7) was originally developedfor small steam pipe line sizes of lessthan 6-inch that were unable to ac-commodate an insertion style desup-erheater. The unit is designed as awafer that is installed between twoflanges in the steam pipe line. A re-duced diameter throat venturi allowswater to spray completely around thewafer and permits multiple points ofspraying either through drilled holes orsmall nozzles. In addition, the venturiincreases the steam velocity at thepoint of injection, which enhances at-omization and mixing in steam flowvelocities as low as approximately 10feet per second (3 meters per second)under optimum conditions. It handlesapplications requiring control overmoderate load change (rangeabilityup to 20:1). It can be installed insteam pipe line sizes of 1-inchthrough 24-inch, and is available formoderate Cv requirements. This de-sign requires an external water controlvalve to meter water flow based on asignal from a temperature sensor inthe downstream steam line.
Understanding SteamConditioning ValvesA steam conditioning valve is used forthe simultaneous reduction of steampressure and temperature to the levelrequired for a given application. Fre-quently, these applications deal withhigh inlet pressures and temperaturesand require significant reductions ofboth properties. They are, therefore,best manufactured in a forged andfabricated body that can better with-stand steam loads at elevated pres-sures and temperatures. Forged ma-terials permit higher design stresses,improved grain structure, and an in-herent material integrity over castvalve bodies. The forged constructionalso allows the manufacturer to pro-vide up to Class 4500, as well as in-termediate and special class ratings,with greater ease versus cast valvebodies.
Due to frequent extreme changes insteam properties as a result of thetemperature and pressure reduction,the forged and fabricated valve bodydesign allows for the addition of anexpanded outlet to control outletsteam velocity at the lower pressure.Similarly, with reduced outlet pres-sure, the forged and fabricated designallows the manufacturer to provide dif-ferent pressure class ratings for the
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inlet and outlet connections to moreclosely match the adjacent piping
Other advantages of combining thepressure reduction and desuperheaterfunction in the same valve versus twoseparate devices include:
� Improved spraywater mixing dueto the optimum utilization of the turbu-lent expansion zone downstream ofthe pressure reduction elements
� Improved rangeability
� Increased noise abatement due,in part, to the additional attenuation ofnoise as a result of the spraywater in-jection
� In some designs, improved re-sponse time due to an integratedfeedforward capability
� Ease of installing and servicingonly one device
Several available steam conditioningvalve designs meet various applica-tions. Typical examples of these fol-low.
Steam ConditioningValves Steam conditioning valves representstate-of-the-art control of steam pres-sure and temperature by integrallycombining both functions within onecontrol element unit. These valves ad-dress the need for better control ofsteam conditions brought on by in-creased energy costs and more rigor-ous plant operation. Steam condition-ing valves also provide bettertemperature control, improved noiseabatement, and require fewer pipingand installation restrictions than theequivalent desuperheater and pres-sure reduction station.
Steam conditioning valve designs canvary considerably, as do the applica-tions they are required to handle.Each has particular characteristics or
Figure 7-8. Steam Conditioning Valve
W8740-2A
options that yield efficient operationover a wide range of conditions andcustomer specified requirements.
The steam-conditioning valve shownin figure 7-8) combines pressure andtemperature control in a single valve.Finite element analysis (FEA) andcomputational fluid dynamic (CFD)tools were used in its development tooptimize the valve’s operating perfor-mance and overall reliability. Therugged design of this steam condition-ing valve proves capable of handlingfull mainstream pressure drops, whileits flow-up configuration in conjunctionwith control valve noise abatementtechnology prevents the generation ofexcessive noise and vibration.
The simplified trim configuration (fig-ure 7-9) used in the steam condition-ing valve accommodates rapidchanges in temperature, as experi-enced during a turbine trip. The cageis case hardened for maximum life
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Figure 7-9. Cross-Section View of Steam ConditioningValve
W8493-1
and is allowed to expand during ther-mally induced excursions. The valveplug is continuously guided and uti-lizes cobalt-based overlays both asguide bands and to provide tight, metal-to-metal shutoff against theseat.
The steam conditioning valve incorpo-rates a spraywater manifold down-stream of its pressure reduction stage.The manifold features variable geom-etry, backpressure activated spraynozzles that maximize mixing andquick vaporization of the spraywater.
The spray nozzle (figure 7-10) wasdeveloped originally for condenserdump systems in which the down-stream steam pressure can fall belowthe saturation level. In theseinstances, the spraywater may flashand significantly change the flow char-acteristic and capacity of the associat-
Figure 7-10. Variable Geometry, Back-pressure Activated Spray Nozzle
W8494-1
ed nozzle at a critical point in the op-eration.
Spring loading of the valve plug withinthe spray nozzle prevents any suchchanges by forcing the plug to close
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Figure 7-11. Steam Cooler
W8786-1
when flashing occurs. With flashing,the compressibility of the fluidchanges, and the nozzle spring willforce closure and re-pressurization ofthe fluid leg. Once this is done, thefluid will regain its liquid propertiesand reestablish flow to the condenser.
The steam conditioning valve injectsthe spray water towards the center ofthe pipeline and away from the pipewall. The number of injection pointsvaries by application. With high differ-entials in steam pressure, the outletsize of the valve increases drasticallyto accommodate the larger specificvolumes. Correspondingly, an in-creased number of nozzles are ar-ranged around the circumference ofthe outlet, making for a more evenand complete distribution of the spraywater.
The simplified trim arrangement in thesteam conditioning valve permits ex-tending its use to higher pressureclasses (through ANSI Class 2500)and operating temperatures. Its bal-anced plug configuration providesClass V shutoff and a linear flow char-acteristic.
The steam conditioning valve typicallyuses high-performance, pneumaticpiston actuators in combination with adigital valve controller to achieve full
stroke in less than two seconds whilemaintaining highly accurate step re-sponse.
When piping dictates, the steam con-ditioning valve can be provided asseparate components, allowing pres-sure control in the valve body andtemperature reduction in a down-stream steam cooler.
Steam CoolerThe steam cooler (figure 7-11) normal-ly is used when an application re-quires a separation of the pressurereduction and desuperheating func-tions. The steam cooler is equippedwith a water supply manifold. Themanifold (multiple manifolds are pos-sible) provides cooling water flow to anumber of individual spray nozzlesinstalled in the pipe wall of the outletsection. The result is a fine spray in-jected radially into the high turbulenceof the axial steam flow. The combina-tion of large surface area contact ofthe water and high turbulence in thesteam make for very efficient mixingand rapid vaporization.
Steam SpargerSteam spargers (figures 7-12 and7-13) are pressure-reducing devicesused to safely discharge steam into a
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Figure 7-12. Steam Sparger withDrilled-Hole Noise Control Technology
W7017-1
Figure 7-13. Steam Sparger UtilizingMulti-Stage Pressure Drop Technique
W8684-2
condenser or turbine exhaust duct. Inaddition, the steam sparger providesbackpressure to the turbine bypassvalve, limits steam velocity and allowsreduced pipe size between the bypassvalve and sparger. The design of thesparger is critical to a properly func-tioning turbine bypass system. To ad-dress flow−induced noise, steamspargers can employ noise abatement
technology. Sparger design and instal-lation are both key elements whenconsidering total system noise.
Understanding TurbineBypass SystemsThe turbine bypass system hasevolved over the last few decades asthe mode of power plant operationshas changed. It is employed routinelyin utility power plants where opera-tions require quick response to wideswings in energy demands. A typicalday of power plant operation mightstart at minimum load, increase to fullcapacity for most of the day, rapidlyreduce back to minimum output, thenup again to full load—all within atwenty-four hour period. Boilers, tur-bines, condensers and other associat-ed equipment cannot respond proper-ly to such rapid changes without someform of turbine bypass system.
The turbine bypass system allows op-eration of the boiler independent ofthe turbine. In the start-up mode, orrapid reduction of generation require-ment, the turbine bypass not only sup-plies an alternate flow path for steam,but conditions the steam to the samepressure and temperature normallyproduced by the turbine expansionprocess. By providing an alternateflow path for the steam, the turbinebypass system protects the turbine,boiler, and condenser from damagethat may occur from thermal and pres-sure excursions. For this reason,many turbine bypass systems requireextremely rapid open/close responsetimes for maximum equipment protec-tion. This is accomplished with anelectrohydraulic actuation system thatprovides both the forces and controlsfor such operation.
Additionally, when commissioning anew plant, the turbine bypass systemallows start-up and check out of theboiler separately from the turbine.This means quicker plant start-ups,which results in attractive economicgains. It also means that this closed
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Figure 7-14. Turbine Bypass System
12
3
4
5
6
Equipment:
1. HP Turbine Bypass Steam Valves2. HP Turbine Bypass Control and Water Isolation Valves3. EHS Electrohydraulic System−
Electrical Control LogicHydraulic Control LogicAccumulators and Accumulator Power System
Hydraulic Power UnitControl CabinetPiston Actuators and Proportional Valves
Equipment:
4. LP Turbine Bypass Steam Valves5. LP Turbine Bypass Water Valves6. LP Turbine Bypass Steam Stop Valves (optional)3. EHS Electrohydraulic system
B2569 / IL
loop system can prevent atmosphericloss of treated feedwater and reduc-tion of ambient noise emissions.
Turbine Bypass SystemComponentsThe major elements of a turbine by-pass system (figure 7-14) are turbinebypass valves, turbine bypass watercontrol valves, and the electro-hydrau-lic system.
Turbine Bypass Valves
Whether for low-pressure orhigh-pressure applications, turbine by-pass valves are usually the manifolddesign steam conditioning valves pre-viously described with tight shutoff(Class V). Because of particular instal-lation requirements these manifold de-sign valves will occasionally be sepa-rated into two parts: thepressure-reducing portion of the valveand then the outlet/manifold cooler
section located closer to the con-denser. Regardless of the configura-tion, however, a cost effective solutionis a fixed-orifice device (usually asparger) located downstream for finalpressure reduction to minimize thesize of the outlet pipe to the con-denser.
Turbine Bypass Water ControlValves
These valves are required to controlthe flow of the water to the turbine by-pass valves. Due to equipmentprotection requirements, it is impera-tive that these valves provide tightshutoff (Class V).
Electro-Hydraulic System
This system is for actuating thevalves. Its primary elements includethe actual hydraulic actuators, the hy-draulic accumulator and power unit,and the control unit and operating logic.
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Chapter 8
Installation and Maintenance
Control valve efficiency directly affectsprocess plant profits. The role a con-trol valve plays in optimizing pro-cesses is often overlooked. Many pro-cess plant managers focus mostresources on distributed control sys-tems and their potential for improvingproduction efficiency. However, it isthe final control element (typically acontrol valve) that actually creates thechange in process variable. If thevalve is not working properly, noamount of sophisticated electronics atthe front end will correct problems atthe valve. As many studies haveshown, control valves are often ne-glected to the point that they becomethe weak link in the process controlscheme.
Control valves must operate properly,no matter how sophisticated the au-tomation system or how accurate theinstrumentation. Without proper valveoperation you cannot achieve high
yields, quality products, maximumprofits, and energy conservation.
Optimizing control valve efficiency de-pends on:
1. Correct control valve selection forthe application,
2. Proper storage and protection,
3. Proper installation techniques, and
4. An effective predictive maintenanceprogram.
Control valve selection is covered inChapter 5. The other three topics areincluded in this chapter.
Proper Storage andProtectionProper storage and protection shouldbe considered early in the selectionprocess, before the valve is shipped.Typically, manufacturers have packag-
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168
ing standards that are dependentupon the destination and intendedlength of storage before installation.Because most valves arrive on sitesome time before installation, manyproblems can be averted by makingsure the details of the installationschedule are known and discussedwith the manufacturer at the time ofvalve selection. In addition, specialprecautions should be taken upon re-ceipt of the valve at the final destina-tion. For example, the valve must bestored in a clean, dry place away fromany traffic or other activity that coulddamage the valve.
Proper InstallationTechniquesAlways follow the control valvemanufacturer’s installation instructionsand cautions. Typical instructions aresummarized here.
Read the Instruction ManualBefore installing the valve, read theinstruction manual. Instruction manu-als describe the product and reviewsafety issues and precautions to betaken before and during installation.Following the guidelines in the manualhelps ensure an easy and successfulinstallation.
Be Sure the Pipeline Is CleanForeign material in the pipeline coulddamage the seating surface of thevalve or even obstruct the movementof the valve plug, ball, or disk so thatthe valve does not shut off properly.To help reduce the possibility of adangerous situation from occurring,clean all pipelines before installing.Make sure pipe scale, metal chips,welding slag, and other foreign materi-als are removed. In addition, inspectpipe flanges to ensure a smooth gas-ket surface. If the valve has screwedend connections, apply a good gradeof pipe sealant compound to the malepipeline threads. Do not use sealant
Figure 8-1. Install the Valve with theFlow Arrow Pointing in the Direction of
the Process Flow
W1916/IL
on the female threads because ex-cess compound on the female threadscould be forced into the valve body.Excess compound could cause stick-ing in the valve plug or accumulationof dirt, which could prevent good valveshutoff.
Inspect the Control ValveAlthough valve manufacturers takesteps to prevent shipment damage,such damage is possible and shouldbe discovered and reported before thevalve is installed.
Do not install a control valve known tohave been damaged in shipment orwhile in storage.
Before installing, check for and re-move all shipping stops and protectiveplugs or gasket surface covers. Checkinside the valve body to make sure noforeign objects are present.
Use Good Piping PracticesMost control valves can be installed inany position. However, the most com-mon method is with the actuator verti-cal and above the valve body. If hori-zontal actuator mounting is necessary,consider additional vertical support forthe actuator. Be sure the body isinstalled so that fluid flow will be in thedirection indicated by the flow arrow(figure 8-1) or instruction manual.
Be sure to allow ample space aboveand below the valve to permit easy re-
Chapter 8. Installation and Maintenance
169
Figure 8-2. Tighten Bolts in aCriss-cross Pattern
A0274-1/IL
moval of the actuator or valve plug forinspection and maintenance. Clear-ance distances are normally availablefrom the valve manufacturer as certi-fied dimension drawings. For flangedvalve bodies, be sure the flanges areproperly aligned to provide uniformcontact of the gasket surfaces. Snugup the bolts gently after establishingproper flange alignment. Finish tight-ening them in a criss-cross pattern(figure 8-2). Proper tightening willavoid uneven gasket loading and willhelp prevent leaks. It also will avoidthe possibility of damaging, or evenbreaking, the flange. This precautionis particularly important when con-necting to flanges that are not thesame material as the valve flanges.
Pressure taps installed upstream anddownstream of the control valve areuseful for checking flow capacity orpressure drop. Locate such taps instraight runs of pipe away from el-bows, reducers, or expanders. Thislocation minimizes inaccuracies re-sulting from fluid turbulence.
Use1/4- or 3/8-inch (6-10 millimeters)tubing or pipe from the pressure con-nection on the actuator to the control-ler. Keep this distance relatively shortand minimize the number of fittingsand elbows to reduce system time lag.If the distance must be long, use avalve positioner or a booster with thecontrol valve.
Control ValveMaintenanceAlways follow the control valvemanufacturer’s maintenance instruc-tions. Typical maintenance topics aresummarized here.
Optimization of control valve assetsdepends on an effective maintenancephilosophy and program. Three of themost basic approaches are:
Reactive – Action is taken after anevent has occurred. Wait for some-thing to happen to a valve and thenrepair or replace it.
Preventive – Action is taken on atimetable based on history; that is, tryto prevent something bad from hap-pening.
Predictive – Action is taken based onfield input using state-of-the-art,non-intrusive diagnostic test andevaluation devices or using smartinstrumentation.
Although both reactive and preventiveprograms work, they do not optimizevalve potential. Following are some ofthe disadvantages of each approach.
Reactive MaintenanceReactive maintenance allows subtledeficiencies to go unnoticed and un-treated, simply because there is noclear indication of a problem. Evencritical valves might be neglected untilthey leak badly or fail to stroke. Insome cases, feedback from produc-tion helps maintenance react beforeserious problems develop, but valvesmight be removed unnecessarily onthe suspicion of malfunction. Largevalves or those welded in-line can re-quire a day or longer for removal, dis-assembly, inspection, and reinstalla-tion. Time and resources could bewasted without solving the problem ifthe symptoms are actually caused bysome other part of the system.
Preventive MaintenancePreventive maintenance generallyrepresents a significant improvement.
Chapter 8. Installation and Maintenance
170
However, because maintenanceschedules have been able to obtainlittle information on valves that are op-erating, many plants simply overhaulall control valves on a rotating sched-ule. Such programs result in servicingsome valves that need no repair oradjustment and leaving others in thesystem long after they have stoppedoperating efficiently.
Predictive MaintenanceToday, plant operators often extendthe time between turnarounds to threeor four years and even longer in orderto maximize process availability.These extended run times offer lessopportunity for traditional, out-of-ser-vice valve diagnostics.
The traditional maintenance processconsists of four distinct modes:
Fault Detection A majority of valvemaintenance effort is spent in monitor-ing valves while in service to detectthe occurrence of a fault. When a faultis identified, the maintenance processtransitions to fault discrimination.
Fault Discrimination During thismode, valve assets are evaluated todetermine the cause of the fault andto establish a course of corrective ac-tion.
Process Recovery Corrective actionis taken to fix the source of the defect.
Validation In this final mode, valveassets are evaluated relative to eitheras−new condition or the last estab-lished baseline condition. Once vali-dated, the maintenance process re-turns to fault detection status.
Using Control ValveDiagnosticsThe advent of micro-processor basedvalve instruments with their in-servicediagnostics capabilities has allowedcompanies to redesign their control
valve maintenance work practices.These digital devices significantly im-prove upon the fault detection and dis-crimination aspects of traditionalmaintenance programs.
For example, in-service diagnostics(figure 8-3) can detect problems withinstrument air quality, leakage andsupply pressure restriction, and canidentify such valve problems as ex-cessive friction and deadband as wellas being out-of-calibration. When aproblem is identified, its severity is re-ported, possible causes are listed anda course of action is given. Thesediagnostics typically result in one ofthree conditions:
� No fault detected (green condi-tion). The valve should remain in ser-vice, and monitoring should continue.
� A warning that a fault has been de-tected, but control remains unaffected(yellow condition). This is a predictiveindication that the detected problem hasthe potential to affect control and thatfuture maintenance should be planned.
� An error report that a fault affectingcontrol has been detected (red condi-tion). These faults generally require im-mediate attention.
More specifically, in-service diagnos-tics oversee:
Instrument Air Leakage
Air mass flow diagnostics measureinstrument air flow through the controlvalve assembly. Because of multiplesensors, this diagnostic can detectboth positive (supply) and negative(exhaust) air mass flow from the DVC.This diagnostic not only detects leaksin the actuator or related tubing, butalso much more difficult problems. Forexample, in piston actuators, the airmass flow diagnostic can detect leak-ing piston seals or damaged O-rings.
Supply Pressure
The supply pressure diagnostic de-tects control valve problems related to
Chapter 8. Installation and Maintenance
171
Figure 8-3. Non-Intrusive Diagnostics Program for Predictive MaintenanceW7046/IL
supply pressure. This in-service diag-nostic will detect both low and highsupply pressure readings. In additionto checking for adequate supply pres-sure, this diagnostic can be used todetect and quantify droop in the airsupply during large travel excursions.This is particularly helpful in identify-ing supply line restrictions.
Travel Deviation and RelayAdjustment
The travel deviation diagnostic is usedto monitor actuator pressure and trav-el deviation from setpoint. This diag-nostic is useful in identifying a stuckcontrol valve, active interlocks, lowsupply pressure or shifts in travel cal-ibration.
The relay adjustment diagnostic isused to monitor crossover pressureon double-acting actuators. If thecrossover pressure is too low, the ac-tuator loses stiffness, making thevalve plug position susceptible to buf-
feting by fluid forces. If the crossoverpressure is set too high, both cham-bers will be near supply, the pneumat-ic forces will be roughly equal, thespring force will be dominant and theactuator will move to its spring-failposition.
Instrument Air Quality
The I/P and relay monitoring diagnos-tic can identify problems such as plug-ging in the I/P primary or in the I/Pnozzle, instrument diaphragm failures,I/P instrument O-ring failures, and I/Pcalibration shifts. This diagnostic isparticularly useful in identifying prob-lems from contaminants in the air sup-ply and from temperature extremes.
In-Service Friction and FrictionTrending
The in-service friction and deadbanddiagnostic determines friction in thevalve assembly as it is controlled bythe control system. Friction diagnos-tics data is collected and trended to
Chapter 8. Installation and Maintenance
172
detect valve changes that affect pro-cess control.
Other Examples
In-service custom diagnostics can beconfigured to collect and graph anymeasured variable of a smart valve.Custom diagnostics can locate anddiscriminate faults not detectable byother means. Often, these faults arecomplicated and require outside ex-pertise. In such cases, data is col-lected by local maintenance personneland is then sent to an expert for fur-ther analysis, thus avoiding the costsand delays associated with an on-sitevisit.
Continued DiagnosticsDevelopment
Overall, the process industries willcontinue to demand more and moreefficiency in terms of quality, yield andreliability. Individually, producers willcontinue to lengthen time betweenturnarounds. These demands will leadto fewer and fewer maintenance man−hours being available for instrumenta-tion repair. The inevitable answer tothis shortfall will be future diagnosticdevelopments that focus on in-ser-vice, non-intrusive test and evaluationcapabilities.
The ability to evaluate valve perfor-mance via in-service diagnostics im-proves turnaround planning as the in-formation gathered can be used topinpoint valve maintenance that isnecessary as well as valves that arehealthy.
An answer is to utilize micro-proces-sor-based valve instrumentation thatevaluates the operating health of thecontrol valve assembly while the valveis in service. Data is collected withoutintruding on normal process opera-tions. The instrumentation analyzesthe information in real-time and pro-vides maintenance recommendationsfor each valve operating problem thatit identifies.
Figure 8-4. TypicalSpring-and-Diaphragm Actuator
W0363/IL
Actuator DiaphragmMost pneumatic spring-and-dia-phragm actuators (figure 8-4) use amolded diaphragm. The molded dia-phragm facilitates installation, pro-vides a relatively uniform effectivearea throughout valve travel, and per-mits greater travel than could be pos-sible with a flat-sheet diaphragm. If aflat-sheet diaphragm is used for emer-gency repair, replace it with a moldeddiaphragm as soon as possible.
Stem PackingPacking (figure 8-5), which providesthe pressure seal around the stem ofa globe-style or angle-style valvebody, should be replaced if leakagedevelops around the stem, or if thevalve is completely disassembled forother maintenance or inspection. Be-fore loosening packing nuts, makesure there is no pressure in the valvebody.
Removing the packing without remov-ing the actuator is difficult and is notrecommended. Also, do not try to
Chapter 8. Installation and Maintenance
173
Figure 8-5. Typical ValveStem Packing Assemblies
W2911/IL
blow out the old packing rings by ap-plying pressure to the lubricator holein the bonnet. This can be dangerous.Also, it frequently does not work verywell as many packing arrangementshave about half of the rings below thelubricator hole.
A better method is to remove the ac-tuator and valve bonnet and pull outthe stem. Push or drive the old pack-ing out the top of the bonnet. Do notuse the valve plug stem because thethreads could sustain damage.
Clean the packing box. Inspect thestem for scratches or imperfectionsthat could damage new packing.Check the trim and other parts as ap-propriate. After re-assembling, tightenbody/bonnet bolting in a sequencesimilar to that described for flangesearlier in this chapter.
Slide new packing parts over the stemin proper sequence, being careful thatthe stem threads do not damage thepacking rings. Adjust packing by fol-lowing the manufacturer’s instructions.
Seat RingsSevere service conditions can dam-age the seating surface of the seatring(s) so that the valve does not shutoff satisfactorily. Grinding or lappingthe seating surfaces will improve shut-off if damage is not severe. For se-vere damage, replace the seat ring.
Grinding Metal SeatsThe condition of the seating surfacesof the valve plug and seat ring canoften be improved by grinding. Manygrinding compounds are availablecommercially. For cage-styleconstructions, bolt the bonnet or bot-tom flange to the body with the gas-kets in place to position the cage andseat ring properly and to help align thevalve plug with the seat ring whilegrinding . A simple grinding tool canbe made from a piece of strap ironlocked to the valve plug stem withnuts.
On double-port bodies, the top ringnormally grinds faster than the bottomring. Under these conditions, continueto use grinding compound on the bot-tom ring, but use only a polishingcompound on the top ring. If either ofthe ports continues to leak, use moregrinding compound on the seat ringthat is not leaking and polishing com-pound on the other ring. This proce-dure grinds down the seat ring that isnot leaking until both seats touch atthe same time. Never leave one seatring dry while grinding the other.
After grinding, clean seating surfaces,and test for shutoff. Repeat grindingprocedure if leakage is still excessive.
Replacing Seat RingsFollow the manufacturer’s instruc-tions. For threaded seat rings, use aseat ring puller (figure 8-6). Before try-ing to remove the seat ring(s), checkto see if the ring has beentack-welded to the valve body. If so,cut away the weld.
On double-port bodies, one of theseat rings is smaller than the other.
Chapter 8. Installation and Maintenance
174
Figure 8-6. Seat Ring Puller
A7097/IL
On direct-acting valves(push-down-to-close action), installthe smaller ring in the body port far-ther from the bonnet before installingthe larger ring. On reverse-actingvalves (push-down-to-open action),install the smaller ring in the body portcloser to the bonnet before installinglarger ring.
Remove all excess pipe compoundafter tightening the threaded seat ring.Spot weld a threaded seat ring inplace to ensure that it does not loos-en.
Bench SetBench set is initial compressionplaced on the actuator spring with a
Figure 8-7. Bench Set Seating Force
A2219/IL
spring adjuster. For air-to-openvalves, the lower bench set deter-mines the amount of seat load forceavailable and the pressure required tobegin valve-opening travel. Forair-to-close valves, the lower benchset determines the pressure requiredto begin valve-closing travel. Seatingforce is determined by pressure ap-plied minus bench set minus springcompression due to travel (figure 8-7).Because of spring tolerances, theremight be some variation in the springangle. The bench set, when the valveis seated, requires the greatest accu-racy. Refer to manufacturer’s instruc-tions for adjusting the spring.
175
Chapter 9
Standards and Approvals
Control Valve StandardsNumerous standards are applicable tocontrol valves. International and glob-al standards are becoming increasing-ly important for companies that partici-pate in global markets. Following is alist of codes and standards that havebeen or will be important in the designand application of control valves.
American Petroleum Institute(API)
Spec 6D, Specification for PipelineValves (Gate, Plug, Ball, and CheckValves)
598, Valve Inspection and Testing
607, Fire Test for Soft-SeatedQuarter-Turn Valves
609, Lug- and Wafer-Type ButterflyValves
American Society of MechanicalEngineers (ASME)B16.1, Cast Iron Pipe Flanges andFlanged Fittings
B16.4, Gray Iron Threaded Fittings
B16.5, Pipe Flanges and FlangedFittings (for steel, nickel-based alloys,and other alloys)
B16.10, Face-to-Face and End-to-EndDimensions of Valves (see ISAstandards for dimensions for mostcontrol valves)
B16.24, Cast Copper Alloy PipeFlanges and Flanged Fittings
B16.25, Buttwelding Ends
B16.34, Valves - Flanged, Threaded,and Welding End
B16.42, Ductile Iron Pipe Flanges andFlanged Fittings
B16.47, Large Diameter Steel Flanges(NPS 26 through NPS 60)
Chapter 9. Standards and Approvals
176
European Committee forStandardization (CEN)
European Industrial ValveStandards
EN 19, Marking
EN 558-1, Face-to-Face andCentre-to-Face Dimensions of MetalValves for Use in Flanged PipeSystems - Part 1: PN-DesignatedValves
EN 558-2, Face-to-Face andCentre-to-Face Dimensions of MetalValves for Use in Flanged PipeSystems - Part 2: Class-DesignatedValves
EN 593, Butterfly valves
EN 736-1, Terminology - Part 1: Defi-nition of types of valves
EN 736-2, Terminology - Part 2:Definition of components of valves
EN 736-3 Terminology - Part 3:Definition of terms (in preparation)
EN 1349, Industrial Process ControlValves (in preparation)
EN 12266-1,Testing of valves - Part 1:Tests, test procedures andacceptance criteria (in preparation)
EN 12516-1, Shell design strength -Part 1: Tabulation method for steelvalves (in preparation)
EN 12516-2, Shell design strength -Part 2: Calculation method for steelvalves (in preparation)
EN 12516-3, Shell design strength -Part 3: Experimental method (inpreparation)
EN 12627, Butt weld end design (inpreparation)
EN 12760, Socket weld end design (inpreparation)
EN 12982, End to end dimensions forbutt welding end valves (inpreparation)
European Material Standards
EN 10213-1, Technical conditions ofdelivery of steel castings for pressurepurposes - Part 1: General
EN 10213-2, Technical conditions ofdelivery of steel castings for pressurepurposes - Part 2: Steel grades foruse at room temperature and elevatedtemperatures
EN 10213-3, Technical conditions ofdelivery of steel castings for pressurepurposes - Part 3: Steel grades foruse at low temperatures
EN 10213-4, Technical conditions ofdelivery of steel castings for pressurepurposes - Part 4: Austenitic andausteno-ferritic steel grades
EN 10222-2, Technical conditions ofdelivery of steel forgings for pressurepurposes - Part 2: Ferritic andmartensitic steels for use at elevatedtemperatures
EN 10222-3, Technical conditions ofdelivery of steel forgings for pressurepurposes - Part 3: Nickel steel for lowtemperature
EN 10222-4, Technical conditions ofdelivery of steel forgings for pressurepurposes - Part 4: Fine grain steel
EN 10222-5, Technical conditions ofdelivery of steel forgings for pressurepurposes - Part 5: Austeniticmartensitic and austeno-ferriticstainless steel
European Flange Standards
EN 1092-1, Part 1: Steel flanges PNdesignated
EN 1092-2 (September 1997), Part 2:Cast iron flanges PN designated
EN 1759-1, Part 1: Steel flangesClass designated (in preparation)
Fluid Controls Institute (FCI)70-2-1991, Control Valve SeatLeakage
Chapter 9. Standards and Approvals
177
Instrument Society of America(ISA)S51.1, Process InstrumentationTerminology
S75.01, Flow Equations for SizingControl Valves
S75.02, Control Valve Capacity TestProcedures
S75.03, Face-to-Face Dimensions forFlanged Globe-Style Control ValveBodies (Classes 125, 150, 250, 300,and 600)
S75.04, Face-to-Face Dimensions forFlangeless Control Valves (Classes150, 300, and 600)
S75.05, Terminology
S75.07, Laboratory Measurement ofAerodynamic Noise Generated byControl Valves
S75.08, Installed Face-to-FaceDimensions for Flanged Clamp orPinch Valves
S75.11, Inherent Flow Characteristicand Rangeability of Control Valves
S75.12, Face-to-Face Dimensions forSocket Weld-End and Screwed-EndGlobe-Style Control Valves (Classes150, 300, 600, 900, 1500, and 2500)
S75.13, Method of Evaluating thePerformance of Positioners withAnalog Input Signals
S75.14, Face-to-Face Dimensions forButtweld-End Globe-Style ControlValves (Class 4500)
S75.15, Face-to-Face Dimensions forButtweld-End Globe-Style ControlValves (Classes 150, 300, 600, 900,1500, and 2500)
S75.16, Face-to-Face Dimensions forFlanged Globe-Style Control ValveBodies (Classes 900, 1500, and 2500)
S75.17, Control Valve AerodynamicNoise Prediction
S75.19, Hydrostatic Testing of ControlValves
S75.20, Face-to-Face Dimensions forSeparable Flanged Globe-StyleControl Valves (Classes 150, 300,and 600)
S75.22, Face-to-CenterlineDimensions for Flanged Globe-StyleAngle Control Valve Bodies (Classes150, 300, and 600)
RP75.23, Considerations forEvaluating Control Valve Cavitation
International ElectrotechnicalCommission (IEC)The majority of International Electro-technical Commission (IEC) standardsfor control valves, several of which arebased on ISA standards. have beenre-published as EN standards and uti-lize an EN prefix. The IEC encouragesnational committees to adopt themand to withdraw any correspondingnational standards. IEC standards areincreasingly being applied bymanufacturers and purchasers. Belowis a list of IEC industrial-process con-trol valve standards (60534 series).
60534-1, Part 1: Control valveterminology and generalconsiderations
60534-2-1, Part 2: Flow capacity -Section One: Sizing equations forincompressible fluid flow underinstalled conditions (based on ISAS75.01)
60534-2-3, Part 2: Flow capacity -Section Three: Test procedures(based on ISA S75.02)
60534-2-4, Part 2: Flow capacity -Section Four: Inherent flowcharacteristics and rangeability(based on ISA S75.11)
60534-4, Part 4: Inspection androutine testing
60534-5, Part 5: Marking
60534-6-1, Part 6: Mounting detailsfor attachment of positioners to controlvalve actuators - Section One:Positioner mounting on linearactuators
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178
60534-6-2, Part 6: Mounting detailsfor attachment of positioners to controlvalve actuators - Section Two:Positioner mounting on rotaryactuators
60534-7, Part 7: Control valve datasheet
60534-8-1, Part 8: Noiseconsiderations - Section One:Laboratory measurement of noisegenerated by aerodynamic flowthrough control valves (based on ISAS75.07)
60534-8-2, Part 8: Noiseconsiderations - Section Two:Laboratory measurement of noisegenerated by hydrodynamic flowthrough control valves
60534-8-3, Part 8: Noiseconsiderations - Section Three:Control valve aerodynamic noiseprediction method (based on ISAS75.17)
60534-8-4, Part 8: Noiseconsiderations - Section Four:Prediction of noise generated byhydrodynamic flow
International StandardsOrganization (ISO)5752, Metal valves for use in flangedpipe systems - Face-to-face andcentre-to-face dimensions
7005-1, Metallic flanges - Part 1: Steelflanges
7005-2, Metallic flanges - Part 2: Castiron flanges
7005-3, Metallic flanges - Part 3:Copper alloy and composite flanges
Manufacturers StandardizationSociety (MSS)SP-6, Standard Finishes for ContactFaces of Pipe Flanges andConnecting-End Flanges of Valvesand Fittings
SP-25, Standard Marking System forValves, Fittings, Flanges and Unions
SP-44, Steel Pipe Line Flanges
SP-67, Butterfly Valves
SP-68, High Pressure Butterfly Valveswith Offset Design
NACE InternationalNACE MR0175/ISO 15156, Petroleumand Natural Gas Industries −Materials for Use in H2S-ContainingEnvironments in Oil and GasProduction
NACE MR0175-2002, Sulfide StressCorrosion Cracking Resistant MetallicMaterials for Oil Field Equipment
NACE MR0103, Materials Resistant toSulfide Stress Cracking in CorrosivePetroleum Refining Envoronments
Product Approvals forHazardous (Classified)Locations
References
Canadian Standards Association(CSA) StandardsC22.1, Canadian Electrical Code(CEC)
C22.2 No. 94-M91, Special IndustrialEnclosures
European Committee forElectrotechnical Standardization(CENELEC) StandardsEN 50014, Electrical apparatus forpotentially explosiveatmospheres—General requirements
Instrument Society of America(ISA) StandardsS12.1, Definitions and InformationPertaining to Electrical Instruments inHazardous (Classified) Locations
International ElectrotechnicalCommission (IEC) Standards60079-4, Electrical apparatus forexplosive gas atmospheres. Part 4:Method of test for ignition temperature
Chapter 9. Standards and Approvals
179
60529, Degrees of protection providedby enclosures (IP Code)
National Electrical Manufacturer’sAssociation (NEMA) Standards
250, Enclosures for ElectricalEquipment (1000 Volts Maximum)
National Fire ProtectionAssociation (NFPA) Standards
70, National Electric Code (NEC)
497M, Classification of Gases, Vaporsand Dusts for Electrical Equipment inHazardous (Classified) Locations
North American ApprovalsThe National Electric Code (NEC) inthe United States and the CanadianElectric Code (CEC) require that elec-trical equipment used in hazardouslocations carry the appropriate ap-proval from a recognized approvalagency.
Approval AgenciesThe three main approval agencies inNorth America are Factory Mutual(FM) and Underwriters Laboratories(UL) in the United States and Cana-dian Standards Association (CSA) inCanada.
Types of Protection The types of protection commonlyused for instruments in North Americaare:
� Dust Ignition−proof: A type ofprotection that excludes ignitableamounts of dust or amounts thatmight affect performance or rating andthat, when installed and protected inaccordance with the original designintent, will not allow arcs, sparks orheat otherwise generated or liberatedinside the enclosure to cause ignitionof exterior accumulations or atmo-spheric suspensions of a specifieddust.
� Explosion−proof: A type ofprotection that utilizes an enclosurethat is capable of withstanding an ex-plosion of a gas or vapor within it andof preventing the ignition of an explo-sive gas or vapor that may surround itand that operates at such an externaltemperature that a surrounding explo-sive gas or vapor will not be ignitedthereby.
� Intrinsically Safe: A type ofprotection in which the electricalequipment under normal or abnormalconditions is incapable of releasingsufficient electrical or thermal energyto cause ignition of a specific hazard-ous atmospheric mixture in its mosteasily ignitable concentration.
� Non−Incendive: A type ofprotection in which the equipment isincapable, under normal conditions, ofcausing ignition of a specified flam-mable gas or vapor-in-air mixture dueto arcing or thermal effect.
NomenclatureApproval agencies within North Ameri-ca classify equipment to be used inhazardous locations by specifying thelocation as being Class I or II; Division1 or 2; Groups A, B, C, D, E, F, or G;and Temperature Code T1 throughT6. These designations are defined inthe NEC and CEC, as well as the fol-lowing paragraphs. The approval con-sists of the type of protection and theclass, division, groups, and tempera-ture, e.g. Class I, Division 1, GroupsA, B, C, D, T6.
Hazardous LocationClassificationHazardous areas in North Americaare classified by class, division, andgroup.
Note
The method of classify-ing locations as zonesinstead of divisions was
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introduced into the 1996edition of the NEC as analternate method, but itis not yet in use. Thezone method is com-mon in Europe andmost other countries.
Class: The Class defines the generalnature of the hazardous material inthe surrounding atmosphere.
� Class I—Locations in whichflammable gases or vapors are, ormay be, present in the air in quantitiessufficient to produce explosive or ignit-able mixtures.
� Class II—Locations that arehazardous because of the presence ofcombustible dusts.
� Class III—Locations in whicheasily ignitable fibers or flyings maybe present but not likely to be in sus-pension in sufficient quantities toproduct ignitable mixtures.
Division: The Division defines theprobability of hazardous material be-ing present in an ignitable concentra-tion in the surrounding atmosphere.See ISA S12.1 for more detailed defi-nitions.
� Division 1: Locations in whichthe probability of the atmosphere be-ing hazardous is high due to flam-mable material being present continu-ously, intermittently, or periodically.
� Division 2: Locations that arepresumed to be hazardous only in anabnormal situation.
Group: The Group defines the haz-ardous material in the surrounding at-mosphere. The specific hazardousmaterials within each group and theirautomatic ignition temperatures canbe found in Article 500 of the NECand in NFPA 497M. Groups A, B, Cand D apply to Class I, and Groups E,F and G apply to Class II locations.The following definitions are from theNEC.
� Group A: Atmospheres con-taining acetylene.
� Group B: Atmospheres con-taining hydrogen, fuel and combus-tible process gases containing morethan 30 percent hydrogen by volume,or gases or vapors of equivalent haz-ard such as butadiene, ethylene ox-ide, propylene oxide, and acrolein.
� Group C: Atmospheres such asethyl ether, ethylene, or gases or va-pors of equivalent hazard.
� Group D: Atmospheres such asacetone, ammonia, benzene, butane,cyclopropane, ethanol, gasoline, hex-ane, methanol, methane, natural gas,naphtha, propane, or gases or vaporsof equivalent hazard.
� Group E: Atmospheres contain-ing combustible metal dusts, includingaluminum, magnesium, and their com-mercial alloy, or other combustibledusts whose particle size, abrasive-ness, and conductivity present similarhazards in the use of electrical equip-ment.
� Group F: Atmospheres contain-ing combustible carbonaceous dusts,including carbon black, charcoal, coal,or dusts that have been sensitized byother materials so that they presentan explosion hazard.
� Group G: Atmospheres con-taining combustible dusts not includedin Group E or F, including flour, grain,wood, plastic, and chemicals.
Temperature CodeA mixture of hazardous gases and airmay be ignited by coming into contactwith a hot surface. The conditions un-der which a hot surface will ignite agas depend on surface area, tempera-ture, and the concentration of the gas.
The approval agencies test and estab-lish maximum temperature ratings forthe different equipment submitted forapproval. Equipment that has been
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tested receives a temperature codethat indicates the maximum surfacetemperature attained by the equip-
ment. The following is a list of the dif-ferent temperature codes:
Class 1 Division 1 Groups ABCD T4
Hazard Type Area Classification Gas or Dust Group Temperature Code
North American TemperatureCodes
TEMPER-ATURECODE
MAXIMUM SURFACETEMPERATURE
�C �F
T1 450 842
T2 300 572
T2A 280 536
T2B 260 500
T2C 230 446
T2D 215 419
T3 200 392
T3A 180 356
T3B 165 329
T3C 160 320
T4 135 275
T4A 120 248
T5 100 212
T6 85 185
The NEC states that any equipmentthat does not exceed a maximum sur-face temperature of 100 �C (212 �F)[based on 40 �C (104 �F) ambienttemperature] is not required to bemarked with the temperature code.Therefore, when a temperature codeis not specified on the approved appa-ratus, it is assumed to be T5.
NEMA Enclosure Rating
Enclosures may be tested to deter-mine their ability to prevent the in-gress of liquids and dusts. In theUnited States, equipment is tested toNEMA 250. Some of the more com-mon enclosure ratings defined inNEMA 250 are as follows.
General Locations
� Type 3 (Dust-tight, Rain-tight,or Ice-resistance, Outdoor enclo-sure): Intended for outdoor use pri-marily to provide a degree of protec-tion against rain, sleet, windblowndust, and damage from external iceformation.
� Type 3R (Rain-proof, Ice-re-sistance, Outdoor enclosure): In-tended for outdoor use primarily toprovide a degree of protection againstrain, sleet, and damage from externalice formation.
� Type 3S (Dust-tight,Rain-tight, Ice-proof, Outdoorenclosure): Intended for outdoor useprimarily to provide a degree ofprotection against rain, sleet, wind-blown dust, and to provide for opera-tion of external mechanisms when iceladened.
� Type 4 (Water-tight,Dust-tight, Ice-resistant, Indoor oroutdoor enclosure): Intended for in-door or outdoor use primarily to pro-vide a degree of protection againstwindblown dust and rain, splashingwater, hose-directed water, and dam-age from external ice formation.
� Type 4X (Water-tight,Dust-tight, Corrosion resistant, In-door or outdoor enclosure): In-tended for indoor or outdoor use pri-marily to provide a degree ofprotection against corrosion, wind-blown dust and rain, splashing water,and hose-directed water, and damagefrom external ice formation.
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Hazardous (Classified) Locations
Two of the four enclosure ratings forhazardous (classified) locations aredescribed as follows in NEMA 250:
� Type 7 (Class I, Division 1,Group A, B, C or D, Indoor hazard-ous location, Enclosure): For in-door use in locations classified asClass I, Division 1, Groups A, B, C orD as defined in the NEC and shall bemarked to show class, division, andgroup. Type 7 enclosures shall be ca-pable of withstanding the pressuresresulting from an internal explosion ofspecified gases, and contain such anexplosion sufficient that an explosivegas-air mixture existing in the atmo-sphere surrounding the enclosure willnot be ignited.
� Type 9 (Class II, Division 1,Groups E, F or G, Indoor hazardouslocation, Enclosure): Intended foruse in indoor locations classified asClass II, Division 1, Groups E, F andG as defined in the NEC and shall bemarked to show class, division, andgroup. Type 9 enclosures shall be ca-pable of preventing the entrance ofdust.
The above two NEMA ratings areoften misunderstood. For example,the above definition of Type 7 is es-sentially the same as that for explo-sion−proof. Therefore, when an ap-proval agency approves equipment asexplosion−proof and suitable for ClassI, Division 1, the equipment automati-cally satisfies the Type 7 requirement;however, the agency does not requirethat the equipment be labeled Type 7.Instead it is labeled as suitable forClass I, Division 1. Similarly, Type 9enclosures would be labeled as suit-able for Class II, Division 1.
CSA Enclosure RatingsCSA enclosure ratings are defined inCSA C22.2, No. 94. They are similarto the NEMA ratings and are desig-nated as type numbers; for example,Type 4. Previously they were desig-
nated with the prefix CSA ENC (forexample, CSA ENC 4).
Intrinsically Safe ApparatusIntrinsically safe apparatus must beinstalled with barriers that limit theelectrical energy into the equipment.Two methods determine acceptablecombinations of intrinsically safe ap-paratus and connected associated ap-paratus (for example, barriers) thathave not been investigated in suchcombination: entity concept and sys-tem parameter concept.
Entity Concept
The entity concept specifies four pa-rameters: voltage, current, capaci-tance, and inductance. The length ofcable connecting intrinsically safeequipment with associated equipmentmay be limited because of the energystoring characteristics of cable. Theentity parameters are:
Vmax = maximum voltage that maysafely be applied to the intrinsicallysafe apparatus.
Imax = maximum current which maysafely be applied to the terminals ofthe intrinsically safe apparatus
Ci = internal unprotected capacitanceof the intrinsically safe apparatus thatcan appear at the terminals of the de-vice under fault conditions
Li = internal unprotected inductanceof the intrinsically safe apparatus thatcan appear at the terminals of the de-vice under fault conditions
Barriers used with the intrinsically safeapparatus must meet the followingconditions, which are noted on theloop schematic (control drawing).
Vmax must be greater than Voc or Vt
Imax must be greater than Isc or It
Ca must be less than (Ci + Ccable)
La must be less than (Li + Lcable)
where:
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Voc or Vt = maximum open circuit volt-age, under fault conditions, of the as-sociated apparatus (barrier). For mul-tiple associated apparatus, FM usesthe maximum combination of voltageVt in place of Voc.
Isc or It = maximum short circuit cur-rent that can be delivered under faultconditions by the associated appara-tus. For multiple associated appara-tus, FM uses the combination of cur-rent It in place of Isc
Ca = maximum capacitance that cansafely be connected to the associatedapparatus
La = maximum inductance that cansafely be connected to the associatedapparatus
Ccable = capacitance of connectingcable
Lcable = inductance of connectingcable
The entity parameters are listed onthe loop schematic (control drawing).The entity concept is used by FM andUL and will be used by CSA if re-quested.
CSA System Parameter Concept
The parametric concept is only usedby CSA. For an intrinsically safe appa-ratus, the parameters are:
� The maximum hazardous loca-tion voltage that may be connected tothe apparatus.
� The minimum resistance inohms of the barrier that may be con-nected to the apparatus.
� CSA will also investigate specificbarriers, which may be listed on theloop schematic along with the para-metric rating.
Loop Schematic (ControlDrawing)Article 504 of the NEC specifically re-quires intrinsically safe and associat-ed apparatus to have a control draw-ing that details the allowedinterconnections between the intrinsi-cally safe and associated apparatus.This drawing may also be referred toas a loop schematic. The drawingnumber is referenced on the appara-tus nameplate and is available to theuser. It must include the following in-formation:
� Wiring diagram: The drawingshall contain a diagram of the appara-tus showing all intrinsically safe termi-nal connections. For intrinsically safeapparatus, all associated apparatusmust be defined either by specificequipment identification or by entityparameters.
� Entity parameters: The entityparameters (or system parameters incase of CSA) shall be supplied in atable showing allowable values foreach applicable Class and Group.
� Hazard location identification:A demarcation line shall be providedon the drawing to show the equipmentin the hazardous location and thenon-hazardous location. The Class,Division, and Group of the hazardouslocation should be identified.
� Equipment identification: Theequipment shall be identified by mod-el, part number, etc. to permit positiveidentification.
� Division 2: Division 2 installa-tion requirements for FM approvedequipment shall be shown.
Comparison of ProtectionTechniques
Explosion-proof Technique:
This technique is implemented by en-closing all electrical circuits in hous-ings and conduits strong enough to
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184
contain any explosion or fires thatmay take place inside the apparatus.
Advantages of this Technique
� Users are familiar with this tech-nique and understand its principlesand applications.
� Sturdy housing designs provideprotection to the internal componentsof the apparatus and allow their ap-plication in hazardous environments.
� An explosion-proof housing isusually weatherproof as well.
Disadvantages of this Technique
� Circuits must be de-energized orlocation rendered nonhazardous be-fore housing covers may be removed.
� Opening of the housing in a haz-ardous area voids all protection.
� Generally this technique re-quires use of heavy bolted or screwedenclosures.
Installation Requirements
� The user has responsibility forfollowing proper installation proce-dures. (Refer to local and nationalelectrical codes.)
� Installation requirements arelisted in Article 501 of the NEC or Ar-ticle 18-106 of the CEC.
� All electrical wiring leading to thefield instrument must be installed us-ing threaded rigid metal conduit,threaded steel intermediate metalconduit, or Type MI cable.
� Conduit seals may be requiredwithin 18 inches of the field instrumentto maintain the explosion−proof ratingand reduce the pressure piling effecton the housing.
Intrinsically Safe Technique:
This technique operates by limitingthe electrical energy available in cir-
cuits and equipment to levels that aretoo low to ignite the most easily ignit-able mixtures of a hazardous area.
Advantages of this Technique
� This technique offers lower cost.No rigid metal conduit or armoredcable are required for field wiring ofthe instrument.
� Greater flexibility is offered sincethis technique permits simple compo-nents such as switches, contact clo-sures, thermocouples, RTD’s, andother non-energy-storing instrumentsto be used without certification butwith appropriate barriers.
� Ease of field maintenance andrepair are advantages. There is noneed to remove power before adjust-ments or calibration are performed onthe field instrument. The system re-mains safe even if the instrument isdamaged, because the energy level istoo low to ignite most easily ignitablemixtures. Diagnostic and calibrationinstruments must have the appropri-ate approvals for hazardous areas.
Disadvantages of this Technique
� This technique requires the useof intrinsically safe barriers to limit thecurrent and voltage between the haz-ardous and safe areas to avoid devel-opment of sparks or hot spots in thecircuitry of the instrument under faultconditions.
� High energy consumption ap-plications are not applicable to thistechnique, because the energy is lim-ited at the source (or barrier). Thistechnique is limited to low-energy ap-plications such as DC circuits,electro-pneumatic converters, etc.
Dust Ignition-proof Technique:
This technique results in an enclosurethat will exclude ignitable amounts ofdusts and will not permit arcs, sparks,or heat otherwise generated inside theenclosure to cause ignition of exterioraccumulations or atmospheric sus-
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185
pension of a specified dust on or nearthe enclosure.
Non-Incendive Technique:
This technique allows for the incorpo-ration of circuits in electrical instru-ments that are not capable of ignitingspecific flammable gases orvapor-in-air mixtures under normal op-erating conditions.
Advantages of this Technique
� This technique uses electronicequipment that normally does not de-velop high temperatures or producesparks strong enough to ignite thehazardous environment.
� There is lower cost than otherhazardous environment protectiontechniques, because there is no needfor explosion−proof housings or ener-gy limiting barriers.
� For non−incendive circuits, theNEC permits any of the wiring meth-
ods suitable for wiring in ordinarylocations.
Disadvantages of this Technique
� This technique is limited to Divi-sion 2 applications only.
� This technique places constrainton control room to limit energy to fieldwiring (normal operation is open, shortor grounding of field wiring) so thatarcs or sparks under normal operationwill not have enough energy to causeignition.
� Both the field instrument andcontrol room device may require morestringent labeling.
European and Asia/PacificApprovals
Approval AgenciesSome of the common approval agen-cies in Europe and Asia/Pacific arelisted below:
Approval AgenciesLocation Abbreviation Agency
United Kingdom BASEEFA British Approvals Service for Electrical Equipment inFlammable Atmospheres
Germany PTB Physikalische-Technische Bundesanstalt
France LCIE Laboratorie Central des Industries Electriques
Australia SAA Standards Association of Australia
Japan JTIISA Japanese Technical Institution of Industry Safety Association
CENELEC Approvals
CENELEC is the acronym for Euro-pean Committee for ElectrotechnicalStandardization. CENELEC standardsare applicable to all European Unioncountries plus other countries thatchoose to use them. A piece of equip-ment that is successfully tested to therelevant CENELEC standard has CE-NELEC approval. The testing may beperformed by any recognized testinglaboratory in Europe. Approvals maybe based on national standards, butCENELEC approvals are preferred.
Types of ProtectionThe types of protection commonlyused outside North America are:
Flameproof:
� A type of protection in which anenclosure can withstand the pressuredeveloped during an internal explo-sion of an explosive mixture and thatprevents the transmission of the ex-plosion to the explosive atmospheresurrounding the enclosure and thatoperates at such an external tempera-ture that a surrounding explosive gas
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186
or vapor will not be ignite there. Thistype of protection is similar to explo-sion−proof. It is referred to by IEC asEx d.
Increased Safety:
� A type of protection in which var-ious measures are applied to reducethe probability of excessive tempera-tures and the occurrence of arcs orsparks in the interior and on the exter-nal parts of electrical apparatus thatdo not produce them in normal ser-vice. Increased safety may be usedwith the flameproof type of protection.This type of protection is referred toby IEC as Ex e.
Intrinsically Safe:
� A type of protection in which theelectrical equipment under normal orabnormal conditions is incapable ofreleasing sufficient electrical or ther-
mal energy to cause ignition of a spe-cific hazardous atmospheric mixture inits most easily ignitable concentration.This type of protection is referred toby IEC as Ex i.
Non-Incendive:
� A type of protection in which theequipment is incapable, under normalconditions, of causing ignition of aspecified flammable gas orvapor-in-air mixture due to arcing orthermal effect. This type of protectionis referred to by IEC as Ex n.
NomenclatureApproval agencies that use the IECnomenclature (for example, BASE-EFA, LCIE, PTB, and SAA) classifyequipment to be used in hazardouslocations by specifying the type ofprotection, gas group, and tempera-ture code as follows:
E Ex ia IIC T4
DenotesCENELECApproval
DenotesHazardousAreaApproval
Types of Protectionia—Intrinsic safety (2 faultsallowed)ib—Intrinsic safety (1 faultallowed)d—Flameproofe—Increased safetyn—Type n (non−incendive)(SAA only)N—Type N (non−incendive)(BASEEFA only)
Group TemperatureCode
For CENELEC approvals, the name-plate must also include the followingsymbol to indicate explosion protec-tion:
This mark indicates compliance withCENELEC requirements and is recog-nized by all European Union membercountries.
Hazardous LocationClassificationHazardous locations outside NorthAmerica are classified by gas groupand zone.
GroupElectrical equipment is divided intotwo groups. Group I covers electricalequipment used in mines, and GroupII covers all other electrical equip-ment. Group II is further subdividedinto three subgroups: A, B, and C.The specific hazardous materials with-in each group can be found in CENE-
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187
LEC EN 50014, and the automaticignition temperatures for some ofthese materials can be found in IEC60079-4.
� Group I (Mining): Atmospherescontaining methane, or gases or va-pors of equivalent hazard.
� Group IIA: Atmospheres con-taining propane, or gases or vapors ofequivalent hazard.
� Group IIB: Atmospheres con-taining ethylene, or gases or vapors ofequivalent hazard.
� Group IIC: Atmospheres con-taining acetylene or hydrogen, orgases or vapors of equivalent hazard.
Note
An apparatus approvedfor one subgroup inGroup II may be used inthe subgroup below it;for example, Group IICmay be used in GroupIIB locations.
Zone
The zone defines the probability ofhazardous material being present inan ignitable concentration in the sur-rounding atmosphere:
� Zone 0: Location where an ex-plosive concentration of a flammablegas or vapor mixture is continuouslypresent or is present for long periods.The area classified as Zone 0, al-though not specifically defined, is con-tained within the United States andCanada classifications of a Division 1location and constitutes an area withthe highest probability that an ignit-able mixture is present.
� Zone 1: Location where an ex-plosive concentration of a flammableor explosive gas or vapor mixture islikely to occur in normal operation.The area classified as Zone 1 is con-
tained within the United States andCanada classifications of a Division 1location.
� Zone 2: Location in which anexplosive concentration of a flam-mable or explosive gas or vapor mix-ture is unlikely to occur in normal op-eration and, if it does occur, will existonly for a short time. Zone 2 is basi-cally equivalent to the United Statesand Canadian classifications of a Divi-sion 2 location.
Temperature CodeA mixture of hazardous gases and airmay be ignited by coming into contactwith a hot surface. The conditions un-der which a hot surface will ignite agas depends on surface area, temper-ature, and the concentration of thegas.
The approval agencies test and estab-lish maximum temperature ratings forthe different equipment submitted forapproval. Group II equipment that hasbeen tested receives a temperaturecode that indicates the maximum sur-face temperature attained by theequipment. It is based on a 40 �C(104 �F) ambient temperature unlessa higher ambient temperature is indi-cated.
IEC Temperature Codes
TEMPERATURECODE
MAXIMUM SURFACETEMPERATURE
�C �F
T1 450 842
T2 300 572
T3 200 392
T4 135 275
T5 100 212
T6 85 185
IEC Enclosure RatingAccording to IEC 60529, the degree ofprotection provided by an enclosure isindicated by the IP Code. The codeconsists of the letters IP (ingressprotection) followed by two character-
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188
istic numerals indicating conformitywith the degree of protection desired(for example, IP54). The first numeralindicates the degree of protectionagainst the following: human contactwith or approach to live parts; humancontact with moving parts inside theenclosure; and ingress of solid foreignobjects. The second numeral indi-cates the degree of protection pro-vided by the enclosure against the in-gress of water. The characteristicnumerals are defined in the followingtable:
NEMA and IEC EnclosureRating ComparisonThe following table provides an equiv-
alent conversion from NEMA typenumbers to IEC IP designations. TheNEMA types meet or exceed the testrequirements for the associated IECclassifications; for this reason, thetable cannot be used to convert fromIEC classification to NEMA types.
Conversion of NEMA Typesto IEC IP Codes
NEMA Type IEC IP
3 IP54
3R IP14
3S IP54
4 and 4X IP65
Ingress Protection (IP) CodesFirst Numeral Protection against solid bodies Second Numeral Protection against liquid
0 No protection 0 No protection
1 Objects greater than 50 mm 1 Vertically dripping water
2 Objects greater than 12.5 mm 2 Angled dripping water (75� to 90�)
3 Objects greater than 2.5 mm 3 Sprayed water
4 Objects greater than 1.0 mm 4 Splashed water
5 Dust-protected 5 Jetting
6 Dust-tight 6 Powerful jetting
- - 7 Temporary immersion
- - 8 Permanent immersion
Comparison of ProtectionTechniques
Flameproof Technique:
This technique is implemented by en-closing all electrical circuits in housingand conduits strong enough to containany explosion or fires that may takeplace inside the apparatus.
Advantages of this Technique
� Users are familiar with this tech-nique and understand its principlesand applications.
� Sturdy housing designs provideprotection to the internal componentsof the apparatus and allow their ap-plication in hazardous environments.
� A flameproof housing is usuallyweatherproof as well.
Disadvantages of this Technique
� Circuits must be de-energized orlocation rendered nonhazardous be-fore housing covers may be removed.
� Opening of the housing in a haz-ardous area voids all protection.
� This technique generally re-quires use of heavy bolted or screwedenclosures.
Increased Safety Technique:
The increased safety technique incor-porates special measures to reducethe probability of excessive tempera-tures and the occurrence of arcs orsparks in normal service.
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189
Advantages of this Technique
� Increased safety enclosures pro-vide at least IP54 enclosure protec-tion.
� Installation and maintenance areeasier for flameproof enclosures.
� This technique offers significant-ly reduced wiring costs over flame-proof installations.
Disadvantages of this Technique
� This technique is limited in theapparatus for which it may be used. Itis normally used for apparatus suchas terminal boxes and compartments.
Intrinsically Safe Technique:
This technique requires the use of in-trinsically safe barriers to limit the cur-rent and voltage between the hazard-ous and safe areas to avoid thedevelopment of sparks or hot spots inthe circuitry of the instrument underfault conditions.
Advantages of this Technique
� This technique costs less be-cause of less stringent rules for fieldwiring of the apparatus.
� Greater flexibility is offered be-cause this technique permits simplecomponents such as switches, con-tact closures, thermocouples, RTD’s,and other non-energy-storing appara-tus to be used without special certifi-cation but with appropriate barriers.
� Ease of field maintenance andrepair characterize this technique.There is no need to remove power be-fore adjustments or calibration areperformed on the field instrument. Thesystem remains safe even if the in-strument is damaged, because theenergy level is too low to ignite mosteasily ignitable mixtures. Diagnostics
and calibration instruments must havethe appropriate approvals for hazard-ous areas.
Disadvantages of this Technique
� High energy consumption ap-plications are not applicable to thistechnique because the energy is limit-ed at the source (or barrier). Thistechnique is limited to low-energy ap-plications such as DC circuits,electro-pneumatic converters, etc.
Type n Technique:
This technique allows for the incorpo-ration of circuits in electrical instru-ments that are not capable of ignitingspecific flammable gases orvapor-in-air mixtures under normal op-erating conditions. This type of protec-tion is not available from CENELEC.
Advantages of this Technique
� This technique uses electronicequipment that normally does not de-velop high temperatures or producesparks strong enough to ignite thehazardous environment.
� Cost is lower than other hazard-ous environment protection tech-niques because there is no need forflameproof housings or energy limitingbarriers.
� This technique provides a de-gree of protection of IP54.
Disadvantages of this Technique
� This technique is applicable toZone 2 locations only.
� Constraints are placed on con-trol room to limit energy to field wiring(normal operation is open, short orgrounding of field wiring) so that arcsor sparks under normal operation willnot have enough energy to cause igni-tion.
Chapter 9. Standards and Approvals
190
191
Chapter 10
Engineering Data
Standard SpecificationsFor Valve Materials
(See table following this listing foradditional specifications, cross-referenced to Material Codenumbers.)
1. Cast Carbon SteelASTM A216 Grade WCCTemp. range = −20 to 800°F (−29 to
427°C)Composition (Percent)
C 0.25 maxMn 1.2 maxP 0.04 maxS 0.045 maxSi 0.6 max
2. Cast Carbon SteelASTM A352 Grade LCCTemp. range = −50 to 650°F (−46 to
343°C)
Composition − Same as ASTM A216grade WCC
3. Carbon Steel BarAISI 1018, UNS G10180Temp. range = −20 to 800°F (−29 to
427°C)Composition (Percent)
C 0.15 to 0.2Mn 0.6 to 0.9P 0.04 maxS 0.05 max
4. Leaded Steel BarAISI 12L14, UNS G12144Temp. range = −20 to 800°F (−29 to
427°C)Composition (Percent)
C 0.15 maxMn 0.85 to 1.15P 0.04 to 0.09S 0.26 to 0.35Pb 0.15 to 0.35
Chapter 10. Engineering Data
192
5. AISI 4140 Cr-Mo Steel(Similar to ASTM A193 Grade B7bolt material)Temp. range = −55°F to 1000°F (−48
to 538°C).Composition (Percent)
C 0.38 to 0.43Mn 0.75 to 1.0P 0.035 maxS 0.035 maxSi 0.15 to 0.35Cr 0.8 to 1.1Mo 0.15 to 0.25Fe Remainder
6. Forged 3-1/2% Nickel SteelASTM A352 Grade LC3Temp. range = −150 to 650°F (−101 to
343°C)Composition (Percent)
C 0.15 maxMn 0.5 to 0.8P 0.04 maxS 0.045 maxSi 0.6 maxNi 3.0 to 4.0
7. Cast Cr-Mo SteelASTM A217 Grade WC6Temp. range = −20 to 1100°F (−29 to
593°C)Composition (Percent)
C 0.05 to 0.2Mn 0.5 to 0.8P 0.04 maxS 0.045 maxSi 0.60 maxCr 1.0 to 1.5Mo 0.45 to 0.65
8. Cast Cr-Mo SteelASTM A217 Grade WC9Temp. range = −20 to 1100°F (−29 to
593°C)Composition (Percent)
C 0.05 to 0.18Mn 0.4 to 0.7P 0.04 maxS 0.045 maxSi 0.6 maxCr 2.0 to 2.75Mo 0.9 to 1.2
9. Forged Cr-Mo SteelASTM A182 Grade F22Temp. range = −20 to 1100°F (−29 to
593°C)Composition (Percent)
C 0.05 to 0.15Mn 0.3 to 0.6P 0.04 maxS 0.04 maxSi 0.5 maxCr 2.0 to 2.5Mo 0.87 to 1.13
10. Cast Cr-Mo SteelASTM A217 Grade C5Temp. range = −20 to 1200°F (−29 to
649°C)Composition (Percent)
C 0.2 maxMn 0.4 to 0.7P 0.04 maxS 0.045 maxSi 0.75 maxCr 4.0 to 6.5Mo 0.45 to 0.65
11. Type 302 Stainless SteelASTM A479 Grade UNS S30200Temp. range = −325 to 1500°F (−198
to 816°C)Composition (Percent)
C 0.15 maxMn 2.0 maxP 0.045 maxS 0.03 maxSi 1.0 maxCr 17.0 to 19.0Ni 8.0 to 10.0N 0.1 maxFe Remainder
12. Type 304L Stainless SteelASTM A479 Grade UNS S30403Temp. range = −425 to 800°F (−254 to
427°C)Composition (Percent)
C 0.03 maxMn 2.0 maxP 0.045 maxS 0.03 maxSi 1.0 maxCr 18.0 to 20.0Ni 8.0 to 12.0
Chapter 10. Engineering Data
193
N 0.1 maxFe Remainder
13. Cast Type 304L Stainless SteelASTM A351 Grade CF3Temp. range = −425 to 800°F (−254 to
427°C)Composition (Percent)
C 0.03 maxMn 1.5 maxSi 2.0 maxS 0.03 maxP 0.045 maxCr 18.0 to 21.0Ni 8.0 to 11.0Mo 0.50 max
14. Type 316L Stainless SteelASTM A479 Grade UNS S31603Temp. range = −425 to 850°F (−254 to
454°C)Composition (Percent)
C 0.03 maxMn 2.0 maxP 0.045 maxS 0.03 maxSi 1.0 maxCr 16.0 to 18.0Ni 10.0 to 14.0Mo 2.0 to 3.0N 0.1 maxFe Remainder
15. Type 316 Stainless SteelASTM A479 Grade UNS S31600Temp. range = −325 to 1500°F (−198
to 816°C); above 1000°F (538C),0.04 C required
Composition (Percent)C 0.08 maxMn 2.0 maxP 0.045 maxS 0.03 maxSi 1.0 maxCr 16.0 to 18.0Ni 10.0 to14.0Mo 2.0 to 3.0N 0.1 maxFe Remainder
16. Cast Type 316 Stainless SteelASTM A351 Grade CF8MTemp. range = −425 to 1500°F (−254
to 816°C); above 1000°F (538C),0.04 C required
Composition (Percent)C 0.08 maxMn 1.5 maxSi 1.5 maxP 0.04 maxS 0.04 maxCr 18.0 to 21.0Ni 9.0 to 12.0Mo 2.0 to 3.0
17. Type 317 Stainless SteelASTM A479 Grade UNS S31700Temp. range = −325 to 1500°F (−198
to 816°C); above 1000°F (538C),0.04 C required
Composition (Percent)C 0.08 maxMn 2.0 maxP 0.045 maxS 0.03 maxSi 1.0 maxCr 18.0 to 20.0Ni 11.0 to15.0Mo 3.0 to 4.0N 0.1 maxFe Remainder
18. Cast Type 317 Stainless SteelASTM A351 Grade CG8MTemp. range = −325 to 1000°F (−198
to 538°C)Composition (Percent)
C 0.08 maxMn 1.5 maxSi 1.5 maxP 0.04 maxS 0.04 maxCr 18.0 to 21.0Ni 9.0 to 13.0Mo 2.0 to 3.0
Chapter 10. Engineering Data
194
19. Type 410 Stainless SteelASTM A276 Grade S41000Temp. range = Annealed
condition,−20 to 1200°F (−29 to649°C); Heat treated 38 HRC, −20to 800°F (−29 to 427°C)
Composition (Percent)C 0.15 maxMn 1.0 maxP 0.04 maxS 0.03 maxSi 1.0 maxCr 11.5 to 13.5Fe Remainder
20. Type 17-4PH Stainless SteelASTM A564 Grade 630, UNS S17400Temp. range = −20 to 650°F (−29 to
343°C). Can be used to 800°F(427°C) for applications, such ascages, where stresses aregenerally compressive, and thereis no impact loading.
Composition (Percent)C 0.07 maxMn 1.0 maxSi 1.0 maxP 0.04 maxS 0.03 maxCr 15.0 to 17.5Nb 0.15 to 0.45Cu 3.0 to 5.0Ni 3.0 to 5.0Fe Remainder
20. Type 254 SMO Stainless SteelASTM A479 Grade UNS S31254Temp. range = −325 to 750°F (−198 to
399)°CComposition (Percent)
C 0.02 maxMn 1.0 maxP 0.03 maxS 0.01 maxSi 0.8 maxCr 18.5 to 20.5Ni 17.5 to 18.5Mo 6.0 to 6.5N 0.18−0.22Fe Remainder
22. Cast Type 254 SMO StainlessSteelASTM A351 Grade CK3MCuNTemp. range = −325 to 750°F (−198 to
399°C)Composition (Percent)
C 0.025 maxMn 1.2 maxSi 1.0 maxP 0.044 maxS 0.01 maxCr 19.5 to 20.5Ni 17.5 to 19.5Mo 6.0 to 7.0
23. Type 2205, S31803 DuplexStainless SteelASTM A279 Grade UNS S31803Temp. range = −20 to 600°F (−29 to
316°C)Composition (Percent)
C 0.03 maxMn 2.0 maxP 0.03 maxS 0.02 maxSi 1.0 maxCr 21.0 to 23.0Ni 4.5 to 6.5Mo 2.5 to 3.5N 0.03 to 0.2Fe Remainder
24. Cast Type 2205, S31803Stainless SteelASTM A890 Grade 4a, CD3MNTemp. range = −20 to 600°F (−29 to
316°C)Composition (Percent)
C 0.03 maxMn 1.5 maxSi 1.0 maxP 0.04 maxS 0.02 maxCr 21.0 to 23.5Ni 4.5 to 6.5Mo 2.5 to 3.5N 0.1 to 0.3Fe Remainder
Chapter 10. Engineering Data
195
25. Cast IronASTM A126 Class B, UNS F12102Temp. range = Pressure Retaining
Components, −20 to 450°F (−29 to232°C); Non-Pressure RetainingComponents, −100 to 800°F (73 to427°C); ANSI B31.5 −150°F(−101°C) minimum if the maximumstress does not exceed 40% of theambient allowable stress.
Composition (Percent)P 0.75 maxS 0.15 max
26. Cast IronASTM A126 Class C, UNS F12802Temp. range = Pressure Retaining
Components, −20 to 450°F (−29 to232°C); Non-Pressure RetainingComponents, −100 to 800°F (73 to427°C); ANSI B31.5 −150°F(−101°C) minimum if the maximumstress does not exceed 40% of theambient allowable stress.
Composition (Percent)P 0.75 maxS 0.15 max
27. Ductile IronASTM A395 Type 60-40-18Temp. range = −20 to 650°F (−29 to
343°C)Composition (Percent)
C 3.0 minSi 2.5 maxP 0.08 max
28. Ductile Ni-Resist IronASTM A439 Type D-2B, UNSF43001Temp. range = −20 to 1400°F (−29 to
760°C)Composition (Percent)
C 3.0 minSi 1.5 to 3.00Mn 0.70 to 1.25P 0.08 maxNi 18.0 to 22.0Cr 2.75 to 4.0
29. Valve BronzeASTM B61, UNS C92200Temp. range = −325 to 550°F (−198 to
288°C)
Composition (Percent)Cu 86.0 to 90.0Sn 5.5 to 6.5Pb 1.0 to 2.0Zn 3.0 to 5.0Ni 1.0 maxFe 0.25 maxS 0.05 maxP 0.05 max
30. Tin BronzeASTM B564 Grade UNS C90500Temp. range = −325 to 400°F (−198 to
204°C)Composition (Percent)
Cu 86.0 to 89.0Sn 9.0 to 11.0Pb 0.30 maxZn 1.0 to 3.0Ni 1.0 maxFe 0.2 maxS 0.05 maxP 0.05 max
31. Manganese BronzeASTM B584 Grade UNS C86500Temp. range = −325 to 350°F (−198 to
177°C)Composition (Percent)
Cu 55.0 to 60.0Sn 1.0 maxPb 0.4 maxNi 1.0 maxFe 0.4 to 2.0Al 0.5 to 1.5Mn 0.1 to 1.5Zn 36.0 to 42.0
32. Cast Aluminum BronzeASTM B148 Grade UNS C95400Temp. range = ANSI B31.1, B31.3,
−325 to 500°F (−198 to 260°C); ASME Section VIII, −325 to 600°F
(−198 to 316°C)Composition (Percent)
Cu 83.0 minAl 10.0 to 11.5Fe 3.0 to 5.0Mn 0.50 maxNi 1.5 max
Chapter 10. Engineering Data
196
33. Cast Aluminum BronzeASTM B148 Grade UNS C95800Temp. range = −325 to 500°F (−198 to
260°C)Composition (Percent)
Cu 79.0 minAl 8.5 to 9.5Fe 3.5 to 4.5Mn 0.8 to 1.5Ni 4.0 to 5.0Si 0.1 max
34. B16 Yellow Brass BarASTM B16 Grade UNS C36000, 1/2
HardTemp. range = Non-Pressure
Retaining Components, −325 to400°F (−198 to 204°C)
Composition (Percent)Cu 60.0 to 63.0Pb 2.5 to 3.7Fe 0.35 maxZn Remainder
35. Naval Brass ForgingsASTM B283 Alloy UNS C46400Temp. range = −325 to 400°F (−198 to
204°C)Composition (Percent)
Cu 59.0 to 62.0Sn 0.5 to 1.0Pb 0.2 maxFe 0.15 maxZn Remainder
36. Aluminum BarASTM B211 Alloy UNS A96061-T6Temp. range = −452 to 400°F (−269
to 204°C)Composition (Percent)
Si 0.4 to 0.8Fe 0.7 maxCu 0.15 to 0.4Zn 0.25 maxMg 0.8 to 1.2Mn 0.15 maxCr 0.04 to 0.35Ti 0.15 maxOther Elements 0.15 maxAl Remainder
37. Cobalt-base Alloy No.6Cast UNS R30006, Weld fillerCoCr-ATemp. range = −325 to 1500°F (−198
to 816°C)Composition (Percent)
C 0.9 to 1.4Mn 1.0 maxW 3.0 to 6.0Ni 3.0Cr 26.0 to 32.0Mo 1.0 maxFe 3.0 maxSi 2.0 maxCo Remainder
38. Ni-Cu Alloy Bar K500B865 Grade N05500Temp. range = −325°F to 900°F
(−198°C to 482°C)Composition (Percent)
Ni 63.0 to 70.0Fe 2.0 maxMn 1.5 maxSi 0.5 maxC 0.25 maxS 0.01 maxP 0.02 maxAl 2.3 to 3.15Ti 0.35 to 0.85Cu Remainder
39. Cast Ni-Cu Alloy 400ASTM A494 Grade M35-1Temp. range = −325 to 900°F (−198 to
482°C)Composition (Percent)
Cu 26.0 to 33.0C 0.35 maxMn 1.5 maxFe 3.5 maxS 0.03 maxP 0.03 maxSi 1.35 maxNb 0.5 maxNi Remainder
40. Ni-Cr-Mo Alloy C276 BarASTM B574 Grade N10276Temp. range = −325 to 1250°F (−198
to 677°C)
Chapter 10. Engineering Data
197
Composition (Percent)Cr 14.5 to 16.5Fe 4.0 to 7.0W 3.0 to 4.5C 0.01 maxSi 0.08 maxCo 2.5 maxMn 1.0 maxV 0.35 maxMo 15.0 to 17.0P 0.04S 0.03Ni Remainder
41. Ni-Cr-Mo Alloy CASTM A494 CW2MTemp. range = −325 to 1000°F (−198
to 538°C)Composition (Percent)
Cr 15.5 to 17.5Fe 2.0 maxW 1.0 maxC 0.02 maxSi 0.8 maxMn 1.0 maxMo 15.0 to 17.5P 0.03S 0.03Ni Remainder
42. Ni-Mo Alloy B2 BarASTM B335 Grade B2, UNS N10665Temp. range = −325 to 800°F (−198 to
427°C)Composition (Percent)
Cr 1.0 maxFe 2.0 maxC 0.02 maxSi 0.1 maxCo 1.0 maxMn 1.0 maxMo 26.0 to 30.0P 0.04 maxS 0.03 maxNi Remainder
43. Cast Ni-Mo Alloy B2ASTM A494 N7MTemp. range = −325 to 1000°F (−198
to 538°C)Composition (Percent)
Cr 1.0 maxFe 3.0 maxC 0.07 maxSi 1.0 maxMn 1.0 maxMo 30.0 to 33.0P 0.04 maxS 0.03 maxNi Remainder
Valve Materials Properties for Pressure−Containing Components (The material codes in this table correspond to the previous Standard
Specifications for Valve Materials listing.)
MATER-IAL
CODE
MINIMUM MECHANICAL PROPERTIESMODULUS OFELASTICITYAT 70�F (21�C) PSI (MPa)
TYPICALBRINELL
HARDNESS
TensileStrength
ksi(MPa)
YieldStrength
ksi(MPa)
Elongationin 2-inch(50 mm)
Reductionin Area
(%)
1 70-95(485-655)
40 (275) 22 35 27.9E6(19.2E4)
137-187
2 70-95(485-655)
40 (275) 22 35 27.9E6(19.2E4)
137-187
3 57 (390)typical
42 (290)typical
37 typical 67 typical - - - 111
4 79 (545)typical
71 (490)typical
16 typical 52 typical - - - 163
5(1) 135 (930)typical
115 (792)typical
22 typical 63 typical 29.9E6(20.6E4)
255
6 70-95(485-655)
40 (275) 24 35 27.9E6(19.2E4)
137
7 70-95(485-655)
40 (275) 20 35 29.9E6(20.6E4)
147-200
(continued)
Chapter 10. Engineering Data
198
Valve Materials Properties for Pressure−Containing Components (continued)(The material codes in this table correspond to the previous Standard
Specifications for Valve Materials listing.)
MATER-IAL
CODE
TYPICALBRINELL
HARDNESS
MODULUS OFELASTICITYAT 70�F (21�C) PSI (MPa)
MINIMUM MECHANICAL PROPERTIES
MATER-IAL
CODE
TYPICALBRINELL
HARDNESS
MODULUS OFELASTICITYAT 70�F (21�C) PSI (MPa)
Reductionin Area
(%)
Elongationin 2-inch(50 mm)
YieldStrength
ksi(MPa)
TensileStrength
ksi(MPa)
8 70-95(485-655)
40 (275) 20 35 29.9E6(20.6E4)
147-200
9 75 (515) 45(310) 20 30 29.9E6(20.6E4)
156-207required
10 90-115(620-795)
60 (415) 18 35 27.4E6(19.0E4)
176-255
11 75 (515) 30 (205) 30 40 28.3E6(19.3E4)
150
12 70 (485) 25 (170) 30 40 29.0E6(20.0E4)
149
13 70 (485) 25 (170) 30 40 29.0E6(20.0E4)
149
14 70 (485) 25 (170) 30 40 28.3E6(19.3E4)
150-170
15(2) 80 (551) 35 (240) 30 40 28.3E6(19.5E4)
150
16 70 (485) 30 (205) 30 − − − 28.3E6(19.5E4)
163
17 75 (515) 35 (240) 25 − − − 28.3E6(19.5E4)
170
18 75 (515) 35 (240) 25 − − − 28.3E6(19.5E4)
170
19 70 (480) 40 (275) 16 45 29.2E6(20.1E4)
223
20 145(1000)
125 (860) 13 45 29E6(20.0E4)
302 min
21 95(665) 44(305) 35 50 29.0E6(20.0E4)
90 HRB
22 80(550) 38(260) 35 - - - 29.0E6(20.0E4)
82 HRB
23 90(620) 65(450) 25 - - - 30.5E6(21.0E4)
290 max
24 90(620) 65(450) 25 - - - 30.5E6(21.0E4)
98 HRB
25(3) 31 (214) − − − − − − − − − 13.4E6(9.2E4)
160-220
26(4) 41 (282) − − − − − − − − − 13.4E6(9.2E4)
160-220
27 60 (415) 40 (276) 18 − − − 23E6(16E4)
143-187
28 58 (400) 30(205) 7 − − − − − − 148-211
29 34 (234) 16(110) 24 − − − 14.0E6(9.7E4)
65
(continued)
Chapter 10. Engineering Data
199
Valve Materials Properties for Pressure−Containing Components (continued)(The material codes in this table correspond to the previous Standard
Specifications for Valve Materials listing.)
MATER-IAL
CODE
TYPICALBRINELL
HARDNESS
MODULUS OFELASTICITYAT 70�F (21�C) PSI (MPa)
MINIMUM MECHANICAL PROPERTIES
MATER-IAL
CODE
TYPICALBRINELL
HARDNESS
MODULUS OFELASTICITYAT 70�F (21�C) PSI (MPa)
Reductionin Area
(%)
Elongationin 2-inch(50 mm)
YieldStrength
ksi(MPa)
TensileStrength
ksi(MPa)
30 40 (275) 18(124) 20 − − − 14.0(9.7E4)
75
31 65 (448) 25(172) 20 − − − 15.3E6(10.5E4)
98
32 75 (515) 30(205) 12 − − − 16E6(11.0E4)
150
33 85 (585) 35(240) 15 − − − 16E6(11.0E4)
120−170
34 55 (380) 25(170) 10 − − − 14E6(9.6E4)
60−80 HRBrequired
35 60 (415) 27(186) 22 − − − 15.0E6(10.3E4)
131−142
36 42 (290) 35(241) 10 − − − 9.9E6(6.8E4)
95
37(5)154
(1060)typical
93(638)typical
17 typical − − − 30E6(21E4)
37 HRC
38 100 (689) 70(485) 20 − − − 26E6(17.9E4)
250−325
39 65 (450) 25(170) 25 − − − 23E6(15.8E4)
110−150
40 100 (689) 41(283) 40 − − − 29.8E6(20.5E4)
210
41 72 (496) 40(275) 20 − − − 30.8E6(21.2E4)
150−185
42 110 (760) 51(350) 40 − − − 31.4E6(21.7E4)
238
43 76 (525) 40(275) 20 − − − 28.5E6(19.7E4)
180
1. Tempered (1200�F (650�C).2. Annealed.3. A126 Cl.B 1.125 in. (95 mm) dia bar.4. A126 Cl.C 1.125 in. (95 mm) dia bar.5. Wrought.
Ch
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200 Physical Constants of Hydrocarbons
NO. COMPOUND FORMULAMOLECULAR
WEIGHT
BOILINGPOINT
AT14.696 PSIA
(�F)
VAPORPRESSURE
AT 100�F(PSIA)
FREEZINGPOINT
AT14.696 PSIA
(�F)
CRITICALCONSTANTS
SPECIFIC GRAVITYAT 14.696 PSIA
CriticalTemperature
(�F)
CriticalPressure
(psia)
Liquid,(3),(4)
60�F/60�F
Gasat
60�F(Air=1)(1)
12345
MethaneEthanePropanen−ButaneIsobutane
CH4C2H6C3H8C4H10C4H10
16.04330.07044.09758.12458.124
−258.69−127.48−43.6731.1010.90
(5000)(2)
(800)(2)
190.51.672.2
−296.46(5)
−297.89(5)
−305.84(5)
−217.05−255.29
−116.6390.09
206.01305.65274.98
667.8707.8616.3550.7529.1
0.3(8)
0.3564(7)
0.5077(7)
0.5844(7)
0.5631(7)
0.55391.03821.52252.00682.0068
678
n−PentaneIsopentaneNeopentane
C5H12C5H12C5H12
72.15172.15172.151
96.9282.1249.10
15.57020.4435.9
−201.51−255.83
2.17
385.7369.10321.13
488.6490.4464.0
0.63100.62470.5967(7)
2.49112.49112.4911
910111213
n−Hexane2−Methylpentane3−MethylpentaneNeohexane2,3−Dimethylbutane
C6H14C6H14C6H14C6H14C6H14
86.17886.17886.17886.17886.178
155.72140.47145.89121.52136.36
4.9566.7676.0989.8567.404
−139.58−244.63
- - -−147.72−199.38
453.7435.83448.3420.13440.29
436.9436.6453.1446.8453.5
0.66400.65790.66890.65400.6664
2.97532.97532.97532.97532.9753
1415161718192021
n−Heptane2−Methylhexane3−Methylhexane3−Ethylpentane2,2−Dimethylpentane2,4−Dimethylpentane3,3−DimethylpentaneTriptane
C7H16C7H16C7H16C7H16C7H16C7H16C7H16C7H16
100.205100.205100.205100.205100.205100.205100.205100.205
209.17194.09197.32200.25174.54176.89186.91177.58
1.6202.2712.1302.0123.4923.2922.7733.374
−131.05−180.89
- - -−181.48−190.86−182.63−210.01−12.82
512.8495.00503.78513.48477.23475.95505.85496.44
396.8396.5408.1419.3402.2396.9427.2428.4
0.68820.68300.69170.70280.67820.67730.69760.6946
3.45963.45963.45963.45963.45963.45963.45963.4596
Ch
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201
Physical Constants of Hydrocarbons (continued)
NO.
SPECIFIC GRAVITYAT 14.696 PSIA
CRITICALCONSTANTSFREEZING
POINTAT
14.696 PSIA(�F)
VAPORPRESSURE
AT 100�F(PSIA)
BOILINGPOINT
AT14.696 PSIA
(�F)
MOLECULARWEIGHTFORMULACOMPOUNDNO. Gas
at60�F
(Air=1)(1)
Liquid,(3),(4)
60�F/60�F
CriticalPressure
(psia)
CriticalTemperature
(�F)
FREEZINGPOINT
AT14.696 PSIA
(�F)
VAPORPRESSURE
AT 100�F(PSIA)
BOILINGPOINT
AT14.696 PSIA
(�F)
MOLECULARWEIGHTFORMULACOMPOUND
222324252627282930
n−OctaneDiisobutylIsooctanen−Nonanen−DecaneCyclopentaneMethylcyclopentaneCyclohexaneMethylcyclohexane
C8H18C8H18C8H18C9H20C10H22C5H10C6H12C6H12C7H14
114.232114.232114.232128.259142.28670.13584.16284.16298.189
258.22228.39210.63303.47345.48120.65161.25177.29213.68
0.5371.1011.7080.1790.05979.9144.5033.2641.609
−70.18−132.07−161.27−64.28−21.36
−136.91−224.44
43.77−195.87
564.22530.44519.46610.68652.1461.5499.35536.7570.27
360.6360.6372.4332.304.653.8548.9591.503.5
0.70680.69790.69620.72170.73420.75040.75360.78340.7740
3.94393.94393.94394.42824.91252.42152.90572.90573.3900
31323334353637383940
EthylenePropene1−ButeneCis−2−ButeneTrans−2−ButeneIsobutene1−Pentene1,2−Butadiene1,3−ButadieneIsoprene
C2H4C3H6C4H8C4H8C4H8C4H8C5H10C4H6C4H6C5H8
28.05442.08156.10856.10856.10856.10870.13554.09254.09268.119
−154.62−53.9020.7538.6933.5819.5985.9351.5324.0693.30
- - -226.463.0545.5449.8063.4019.115
(20.)(2)
(60.)(2)
16.672
−272.45(5)
−301.45(5)
−301.63(5)
−218.06−157.96−220.61−265.39−213.16−164.02−230.74
48.58196.9295.6324.37311.86292.55376.93
(339.)(2)
306.(412.)(2)
729.8669.583.610.595.580.590.
(653.)(2)
628.(558.4)(2)
- - -0.5220(7)
0.6013(7)
0.6271(7)
0.6100(7)
0.6004(7)
0.64570.6587
0.6272(7)
0.6861
0.96861.45291.93721.93721.93721.93722.42151.86761.86762.3519
Ch
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202 Physical Constants of Hydrocarbons (continued)
NO.
SPECIFIC GRAVITYAT 14.696 PSIA
CRITICALCONSTANTSFREEZING
POINTAT
14.696 PSIA(�F)
VAPORPRESSURE
AT 100�F(PSIA)
BOILINGPOINT
AT14.696 PSIA
(�F)
MOLECULARWEIGHTFORMULACOMPOUNDNO. Gas
at60�F
(Air=1)(1)
Liquid,(3),(4)
60�F/60�F
CriticalPressure
(psia)
CriticalTemperature
(�F)
FREEZINGPOINT
AT14.696 PSIA
(�F)
VAPORPRESSURE
AT 100�F(PSIA)
BOILINGPOINT
AT14.696 PSIA
(�F)
MOLECULARWEIGHTFORMULACOMPOUND
414243444546474849
AcetyleneBenzeneTolueneEthylbenzeneo−Xylenem−Xylenep−XyleneStyreneIsopropylbenzene
C2H2C6H6C7H8C8H10C8H10C8H10C8H10C8H8C9H12
26.03878.11492.141
106.168106.168106.168106.168104.152120.195
−119.(6)
176.17231.13277.16291.97282.41281.05293.29306.34
- - -3.2241.0320.3710.2640.3260.342
(0.24)(2)
0.188
−114(5)
41.96−138.94−138.91−13.30−54.1255.86
−23.10−140.82
95.31552.22605.55651.24675.0651.02649.6706.0676.4
890.4710.4595.9523.5541.4513.6509.2580.465.4
0.615(9)
0.88440.87180.87180.88480.86870.86570.91100.8663
0.89902.69693.18123.66553.66553.66553.66553.59594.1498
1. Calculated values.2. ( )−Estimated values.3. Air saturated hydrocarbons.4. Absolute values from weights in vacuum.5. At saturation pressure (triple point).6. Sublimation point.7. Saturation pressure and 60�F.8. Apparent value for methane at 60�F.9. Specific gravity, 119�F/60�F (sublimation point).
Specific Heat Ratio (k)
Gas Specific HeatRatio (k)
Gas Specific HeatRatio (k)
Gas Specific HeatRatio (k)
Gas Specific HeatRatio (k)
AcetyleneAirArgonButaneCarbon Monoxide
1.381.401.671.171.40
Carbon DioxideEthaneHeliumHydrogenMethane
1.291.251.661.401.26
0.6 Natural GasNitrogenOxygenPropanePropylene
1.321.401.401.211.15
Steam(1) 1.33
1. Use property tables if available for greater accuracy.
Ch
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203
Physical Constants of Various Fluids
FLUID FORMULA MOLECULARWEIGHT
BOILING POINT(�F AT 14.696
PSIA)
VAPORPRESSURE
@ 70�F(PSIG)
CRITICALTEMP.
(�F)
CRITICALPRESSURE
(PSIA)
SPECIFIC GRAVITY
Liquid60/60�F
Gas
Acetic Acid HC2H3O2 60.05 245 1.05
Acetone C3H6O 58.08 133 455 691 0.79 2.01
Air N2O2 28.97 −317 −221 547 0.86(3) 1.0
Alcohol, Ethyl C2H6O 46.07 173 2.3(2) 470 925 0.794 1.59
Alcohol, Methyl CH4O 32.04 148 4.63(2) 463 1174 0.796 1.11
Ammonia NH3 17.03 −28 114 270 1636 0.62 0.59
Ammonium Chloride(1) NH4CI 1.07
Ammonium Hydroxide(1) NH4OH 0.91
Ammonium Sulfate(1) (NH4)2SO4 1.15
Aniline C6H7N 93.12 365 798 770 1.02
Argon A 39.94 −302 −188 705 1.65 1.38
Beer 1.01
Bromine Br2 159.84 138 575 2.93 5.52
Calcium Chloride(1) CaCI2 1.23
Carbon Dioxide CO2 44.01 −109 839 88 1072 0.801(3) 1.52
Carbon Disulfide CS2 76.1 115 1.29 2.63
Carbon Monoxide CO 28.01 −314 −220 507 0.80 0.97
Carbon Tetrachloride CCI4 153.84 170 542 661 1.59 5.31
Chlorine CI2 70.91 −30 85 291 1119 1.42 2.45
Chromic Acid H2CrO4 118.03 1.21
Citric Acid C6H8O7 192.12 1.54
Copper Sulfate(1) CuSO4 1.17
(continued)
Ch
apter 10. E
ng
ineerin
g D
ata
204 Physical Constants of Various Fluids (continued)
FLUID
SPECIFIC GRAVITYCRITICALPRESSURE
(PSIA)
CRITICALTEMP.
(�F)
VAPORPRESSURE
@ 70�F(PSIG)
BOILING POINT(�F AT 14.696
PSIA)
MOLECULARWEIGHT
FORMULAFLUIDGasLiquid
60/60�F
CRITICALPRESSURE
(PSIA)
CRITICALTEMP.
(�F)
VAPORPRESSURE
@ 70�F(PSIG)
BOILING POINT(�F AT 14.696
PSIA)
MOLECULARWEIGHT
FORMULA
Ether (C2H5)2O 74.12 34 0.74 2.55
Ferric Chloride(1) FeCI3 1.23
Fluorine F2 38.00 −305 300 −200 809 1.11 1.31
Formaldehyde H2CO 30.03 −6 0.82 1.08
Formic Acid HCO2H 46.03 214 1.23
Furfural C5H4O2 96.08 324 1.16
Glycerine C3H8O3 92.09 554 1.26
Glycol C2H6O2 62.07 387 1.11
Helium He 4.003 −454 −450 33 0.18 0.14
Hydrochloric Acid HCI 36.47 −115 1.64
Hydrofluoric Acid HF 20.01 66 0.9 446 0.92
Hydrogen H2 2.016 −422 −400 188 0.07(3) 0.07
Hydrogen Chloride HCI 36.47 −115 613 125 1198 0.86 1.26
Hydrogen Sulfide H2S 34.07 −76 252 213 1307 0.79 1.17
Isopropyl Alcohol C3H8O 60.09 180 0.78 2.08
Linseed Oil 538 0.93
Mangesium Chloride(1) MgCI2 1.22
Mercury Hg 200.61 670 13.6 6.93
Methyl Bromide CH3Br 94.95 38 13 376 1.73 3.27
Methyl Chloride CH3CI 50.49 −11 59 290 969 0.99 1.74
Naphthalene C10H8 128.16 424 1.14 4.43
Nitric Acid HNO3 63.02 187 1.5
(continued)
Ch
apter 10. E
ng
ineerin
g D
ata
205
Physical Constants of Various Fluids (continued)
FLUID
SPECIFIC GRAVITYCRITICALPRESSURE
(PSIA)
CRITICALTEMP.
(�F)
VAPORPRESSURE
@ 70�F(PSIG)
BOILING POINT(�F AT 14.696
PSIA)
MOLECULARWEIGHT
FORMULAFLUIDGasLiquid
60/60�F
CRITICALPRESSURE
(PSIA)
CRITICALTEMP.
(�F)
VAPORPRESSURE
@ 70�F(PSIG)
BOILING POINT(�F AT 14.696
PSIA)
MOLECULARWEIGHT
FORMULA
Nitrogen N2 28.02 −320 −233 493 0.81(3) 0.97
Oil, Vegetable 0.91−0.94
Oxygen O2 32 −297 −181 737 1.14(3) 1.105
Phosgene COCI2 98.92 47 10.7 360 823 1.39 3.42
Phosphoric Acid H3PO4 98.00 415 1.83
Potassium Carbonate(1) K2CO3 1.24
Potassium Chloride(1) KCI 1.16
Potassium Hydroxide(1) KOH 1.24
Sodium Chloride(1) NaCI 1.19
Sodium Hydroxide(1) NaOH 1.27
Sodium Sulfate(1) Na2SO4 1.24
Sodium Thiosulfate(1) Na2S2O3 1.23
Starch (C6H10O5)x 1.50
Sugar Solutions(1) C12H22011 1.10
Sulfuric Acid H2SO4 98.08 626 1.83
Sulfur Dioxide SO2 64.6 14 34.4 316 1145 1.39 2.21
Turpentine 320 0.87
Water H2O 18.016 212 0.9492(2) 706 3208 1.00 0.62
Zinc Chloride(1) ZnCI2 1.24
Zinc Sulfate(1) ZnSO4 1.31
1. Aqueous Solution − 25% by weight of compound.2. Vapor pressure in psia at 100�F3. Vapor pressure in psia.
Chapter 10. Engineering Data
206
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated Vapor
TEMP(�F)
PRESSUREVOLUME
(CU.FT./LB.)
DENSITY(LB./CU.
FT.)
ENTHALPY(1)
(BTU/LB.)ENTROPY(1)
BTU/(LB.)(�R)
psia psig VaporVg
LiquidI/vf
Liquidhf
Vaporhg
Liquidsf
Vaporsg
−105−104−103−102−101
−100−99−98−97−96
−95−94−93−92−91
−90−89−88−87−86
−85−84−83−82−81
−80−79−78−77−76
−75−74−73−72−71
−70−69−68−67−66
−65−64−63−62−61−60
0.9961.0411.0871.1351.184
1.241.291.341.401.46
1.521.591.651.721.79
1.861.942.022.102.18
2.272.352.452.542.64
2.742.842.953.063.18
3.293.423.543.673.80
3.944.084.234.384.53
4.694.855.025.195.375.55
27.9(2)
27.8(2)
27.7(2)
27.6(2)
27.5(2)
27.4(2)
27.3(2)
27.2(2)
27.1(2)
26.9(2)
26.8(2)
26.7(2)
26.6(2)
26.4(2)
26.3(2)
26.1(2)
26.0(2)
25.8(2)
25.6(2)
25.5(2)
25.3(2)
25.1(2)
24.9(2)
24.7(2)
24.5(2)
24.3(2)
24.1(2)
23.9(2)
23.7(2)
23.5(2)
23.2(2)
23.0(2)
22.7(2)
22.4(2)
22.2(2)
21.9(2)
21.6(2)
21.3(2)
21.0(2)
20.7(2)
20.4(2)
20.0(2)
19.7(2)
19.4(2)
19.0(2)
18.6(2)
223.2214.2205.7197.6189.8
182.4175.3168.5162.1155.9
150.0144.3138.9133.8128.9
124.1119.6115.3111.1107.1
103.399.6896.1792.8189.59
86.5083.5480.6977.9675.33
72.8170.3968.0665.8263.67
61.6059.6157.6955.8554.08
52.3750.7349.1447.6246.1544.73
45.7145.6745.6345.5945.55
45.5245.4745.4345.4045.36
45.3245.2845.2445.2045.16
45.1245.0845.0445.0044.96
44.9244.8844.8444.8044.76
44.7344.6844.6444.6044.56
44.5244.4844.4444.4044.36
44.3244.2844.2444.1944.15
44.1144.0744.0343.9943.9543.91
−68.5−67.5−66.4−65.4−64.3
−63.3−62.2−61.2−60.1−59.1
−58.0−57.0−55.9−54.9−53.8
−52.8−51.7−50.7−49.6−48.6
−47.5−46.5−45.4−44.4−43.3
−42.2−41.2−40.1−39.1−38.0
−37.0−35.9−34.9−33.8−32.8
−31.7−30.7−29.6−28.6−27.5
−26.5−25.4−24.4−23.3−22.2−21.2
570.3570.7571.2571.6572.1
572.5572.9573.4573.8574.3
574.7575.1575.6576.0576.5
576.9577.3577.8578.2578.6
579.1579.5579.9580.4580.8
581.2581.6582.1582.5582.9
583.3583.8584.2584.6585.0
585.5585.9586.3586.7587.1
587.5588.0588.4588.8589.2589.6
−0.1774−.1774−.1714−.1685−.1655
−0.1626−.1597−.1568−.1539−.1510
−0.1481−.1452−.1423−.1395−.1366
−0.1338−.1309−.1281−.1253−.1225
−0.1197−.1169−.1141−.1113−.1085
0.1057−.1030−.1002−.0975−.0947
−0.0920−.0892−.0865−.0838−.0811
−0.0784−.0757−.0730−.0703−.0676
−0.0650−.0623−.0596−.0570−.0543−.0517
1.62431.62051.61671.61291.6092
1.60551.60181.59821.59451.5910
1.58741.58381.58031.57681.5734
1.56991.56651.56311.55971.5564
1.55311.54981.54651.54321.5400
1.53681.53361.53041.52731.5242
1.52111.51801.51491.51191.5089
1.50591.50291.49991.49701.4940
1.49111.48831.48541.48261.47971.4769
(continued)
Chapter 10. Engineering Data
207
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated Vapor (continued)
TEMP(�F)
ENTROPY(1)
BTU/(LB.)(�R)ENTHALPY(1)
(BTU/LB.)
DENSITY(LB./CU.
FT.)
VOLUME(CU.
FT./LB.)PRESSURE
TEMP(�F)
Vaporsg
Liquidsf
Vaporhg
Liquidhf
LiquidI/vf
VaporVg
psigpsia
−59−58−57−56−55
−54−53−52−51−50
−49−48−47−46−45
−44−43−42−41−40
−39−38−37−36−35
−34−33−32−31−30
−29−28−27−26−25
−24−23−22−21−20
−19−18−17−16−15−14
5.745.936.136.336.54
6.756.977.207.437.67
7.918.168.428.688.95
9.239.519.8110.1010.41
10.7211.0411.3711.7112.05
12.4112.7713.1413.5213.90
14.3014.7115.1215.5515.98
16.2416.8817.3417.8118.30
18.7919.3019.8120.3420.8821.43
18.2(2)
17.8(2)
17.4(2)
17.0(2)
16.6(2)
16.2(2)
15.7(2)
15.3(2)
14.8(2)
14.3(2)
13.8(2)
13.3(2)
12.8(2)
12.2(2)
11.7(2)
11.1(2)
10.6(2)
10.0(2)
9.3(2)
8.7(2)
8.1(2)
7.4(2)
6.8(2)
6.1(2)
5.4(2)
4.7(2)
3.9(2)
3.2(2)
2.4(2)
1.6(2)
0.8(2)
0.00.40.81.3
1.72.22.63.13.6
4.14.65.15.66.26.7
43.3742.0540.7939.5638.38
37.2436.1535.0934.0633.08
32.1231.2030.3129.4528.62
27.8227.0426.2925.5624.86
24.1823.5322.8922.2721.68
21.1020.5420.0019.4818.97
18.4818.0017.5417.0916.66
16.2415.8315.4315.0514.68
14.3213.9713.6213.2912.9712.66
43.8743.8343.7843.7443.70
43.6643.6243.5843.5443.49
43.4543.4143.3743.3343.28
43.2443.2043.1643.1243.08
43.0442.9942.9542.9042.86
42.8242.7842.7342.6942.65
42.6142.5742.5442.4842.44
42.4042.3542.3142.2642.22
42.1842.1342.0942.0442.0041.96
−20.1−19.1−18.0−17.0−15.9
−14.8−13.8−12.7−11.7−10.6
−9.6−8.5−7.4−6.4−5.3
−4.3−3.2−2.1−1.10.0
1.12.13.24.35.3
6.47.48.59.610.7
11.712.813.914.916.0
17.118.119.220.321.4
22.423.524.625.626.727.8
590.0590.4590.8591.2591.6
592.1592.4592.9593.2593.7
594.0594.4594.9595.2595.6
596.0596.4596.8597.2597.6
598.0598.3598.7599.1599.5
599.9600.2600.6601.0601.4
601.7602.1602.5602.8603.2
603.6603.9604.3604.6605.0
605.3605.7606.1606.4606.7607.1
−0.0490−.0464−.0438−.0412−.0386
−0.0360−.0334−.0307−.0281−.0256
−0.0230−.0204−.0179−.0153−.0127
−0.0102−.0076−.0051−.0025.0000
0.0025.0051.0076.0101.0126
0.0151.0176.0201.0226.0250
0.0275.0300.0325.0350.0374
0.0399.0423.0448.0472.0497
0.0521.0545.0570.0594.0618.0642
1.47411.47131.46861.46581.4631
1.46041.45771.45511.45241.4497
1.44711.44451.44191.43931.4368
1.43421.43171.42921.42671.4242
1.42171.41931.41691.41441.4120
1.40961.40721.40481.40251.4001
1.39781.39551.39321.39091.3886
1.38631.38401.38181.37961.3774
1.37521.37291.37081.36861.36641.3642
(continued)
Chapter 10. Engineering Data
208
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated Vapor (continued)
TEMP(�F)
ENTROPY(1)
BTU/(LB.)(�R)ENTHALPY(1)
(BTU/LB.)
DENSITY(LB./CU.
FT.)
VOLUME(CU.
FT./LB.)PRESSURE
TEMP(�F)
Vaporsg
Liquidsf
Vaporhg
Liquidhf
LiquidI/vf
VaporVg
psigpsia
−13−12−11−10−9
−8−7−6−5−4
−3−2−101
234
5(3)
6
7891011
1213141516
1718192021
2223242526
272829303132
21.9922.5623.1523.7424.35
24.9725.6126.2626.9227.59
28.2828.9829.6930.4231.16
31.9232.6933.4734.2735.09
35.9236.7737.6338.5139.40
40.3141.2442.1843.1444.12
45.1246.1347.1648.2149.28
50.3651.4752.5953.7354.90
56.0857.2858.5059.7461.0062.29
7.37.98.59.09.7
10.310.911.612.212.9
13.614.315.015.716.5
17.218.018.819.620.4
21.222.122.923.824.7
25.626.527.528.429.4
30.431.432.533.534.6
35.736.837.939.040.2
41.442.643.845.046.347.6
12.3612.0611.7811.5011.23
10.9710.7110.4710.239.991
9.7639.5419.3269.1168.912
8.7148.5218.3338.1507.971
7.7987.6297.4647.3047.148
6.9966.8476.7036.5626.425
6.2916.1616.0345.9105.789
5.6715.5565.4435.3345.227
5.1235.0214.9224.8254.7304.637
41.9141.8741.8241.7841.74
41.6941.6541.6041.5641.52
41.4741.4341.3841.3441.29
41.2541.2041.1641.1141.07
41.0140.9840.9340.8940.84
40.8040.7540.7140.6640.61
40.5740.5240.4840.4340.38
40.3440.2940.2540.2040.15
40.1040.0640.0139.9639.9139.86
28.930.031.032.133.2
34.335.436.437.538.6
39.740.741.842.944.0
45.146.247.248.349.4
50.551.652.753.854.9
56.057.158.259.260.3
61.462.563.664.765.8
66.968.069.170.271.3
72.473.574.675.776.877.9
607.5607.8608.1608.5608.8
609.2609.5609.8610.1610.5
610.8611.1611.4611.8612.1
612.4612.7613.0613.3613.6
613.9614.3614.6614.9615.2
615.5615.8616.1616.3616.6
616.9617.2617.5617.8618.0
618.3618.6618.9619.1619.4
619.7619.9620.2620.5620.7621.0
0.0666.0690.0714.0738.0762
0.0786.0809.0833.0857.0880
0.0909.0928.0951.0975.0998
0.1022.1045.1069.1092.1115
0.1138.1162.1185.1208.1231
0.1254.1277.1300.1323.1346
0.1369.1392.1415.1437.1460
0.1483.1505.1528.1551.1573
0.1596.1618.1641.1663.1686.1708
1.36241.36001.35791.35581.3537
1.35161.34931.34741.34541.3433
1.34131.33931.33721.33521.3332
1.33121.32921.32731.32531.3234
1.32141.31951.31761.31571.3137
1.31181.30991.30811.30621.3043
1.30251.30061.29881.29691.2951
1.29331.29151.28971.28791.2861
1.28431.28231.28091.27901.27731.2755
(continued)
Chapter 10. Engineering Data
209
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated Vapor (continued)
TEMP(�F)
ENTROPY(1)
BTU/(LB.)(�R)ENTHALPY(1)
(BTU/LB.)
DENSITY(LB./CU.
FT.)
VOLUME(CU.
FT./LB.)PRESSURE
TEMP(�F)
Vaporsg
Liquidsf
Vaporhg
Liquidhf
LiquidI/vf
VaporVg
psigpsia
3334353637
3839404142
4344454647
4849505152
5354555657
5859606162
6364656667
6869707172
737475767778
63.5964.9166.2667.6369.02
70.4371.8773.3274.8076.31
77.8379.3880.9682.5584.18
85.8287.4989.1990.9192.66
94.4396.2398.0699.91101.8
103.7105.6107.6109.6111.6
113.6115.7117.8120.0122.1
124.3126.5128.8131.1133.4
135.7138.1140.5143.0145.4147.9
48.950.251.652.954.3
55.757.258.660.161.6
63.164.766.367.969.5
71.172.874.576.278.0
79.781.583.485.287.1
89.090.992.994.996.9
98.9101.0103.1105.3107.4
109.6111.8114.1116.4118.7
121.0123.4125.8128.3130.7133.2
4.5474.4594.3734.2894.207
4.1264.0483.9713.8973.823
3.7523.6823.6143.5473.481
3.4183.3553.2943.2343.176
3.1193.0633.0082.9542.902
2.8512.8002.7512.7032.656
2.6102.5652.5202.4772.435
2.3932.3522.3122.2732.235
2.1972.1612.1252.0892.0552.021
39.8239.7739.7239.6739.63
39.5839.5439.4939.4439.39
39.3439.2939.2439.1939.14
39.1039.0539.0038.9538.90
38.8538.8038.7538.7038.65
38.6038.5538.5038.4538.40
38.3538.3038.2538.2038.15
38.1038.0538.0037.9537.90
37.8437.7937.7437.6937.6437.58
79.080.181.282.383.4
84.685.786.887.989.0
90.191.292.393.594.6
95.796.897.999.1
100.2
101.3102.4103.5104.7105.8
106.9108.1109.2110.3111.5
112.6113.7114.8116.0117.1
118.3119.4120.5121.7122.8
124.0125.1126.2127.4128.5129.7
621.2621.5621.7622.0622.2
622.5622.7623.0623.2623.4
623.7623.9624.1624.4624.6
624.8625.0625.2625.5625.7
625.9626.1626.3626.5626.7
626.9627.1627.3627.5627.7
627.9628.0628.2628.4628.6
628.8628.9629.1629.3629.4
629.6629.8629.9630.1630.2630.4
0.1730.1753.1775.1797.1819
0.1841.1863.1885.1908.1930
0.1952.1974.1996.2018.2040
0.2062.2083.2105.2127.2149
0.2171.2192.2214.2236.2257
0.2279.2301.2322.2344.2365
0.2387.2408.2430.2451.2473
0.2494.2515.2537.2558.2579
0.2601.2622.2643.2664.2685.2706
1.27381.27211.27041.26861.2669
1.26521.26351.26181.26021.2585
1.25681.25521.25351.25181.2492
1.24841.24691.24531.24371.2421
1.24051.23821.23721.23571.2341
1.23251.23101.22941.22731.2263
1.22471.22311.22131.22011.2183
1.21791.21551.21401.21251.2110
1.20951.20801.20651.20501.20351.2020
(continued)
Chapter 10. Engineering Data
210
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated Vapor (continued)
TEMP(�F)
ENTROPY(1)
BTU/(LB.)(�R)ENTHALPY(1)
(BTU/LB.)
DENSITY(LB./CU.
FT.)
VOLUME(CU.
FT./LB.)PRESSURE
TEMP(�F)
Vaporsg
Liquidsf
Vaporhg
Liquidhf
LiquidI/vf
VaporVg
psigpsia
7980818283
8485
86(3)
8788
8990919293
9495969798
99100101102103
104105106107108
109110111112113
114115116117118119
120121122123124125
150.5153.0155.6158.3161.0
163.7166.4169.2172.0174.8
177.7180.6183.6186.6189.6
192.7195.8198.9202.1205.3
208.6211.9215.2218.6222.0
225.4228.9232.5236.0239.7
243.3247.0250.8254.5258.4
262.2266.2270.1274.1278.2282.3
286.4290.6294.8299.1303.4307.8
135.8138.3140.9143.6146.3
149.0151.7154.5157.3160.1
163.0165.9168.9171.9174.9
178.0181.1184.2187.4190.6
193.9197.2200.5203.9207.3
210.7214.2217.8221.3225.0
228.6232.3236.1239.8243.7
247.5251.5255.4259.4263.5267.6
271.7275.9280.1284.4288.7293.1
1.9881.9551.9231.8921.861
1.8311.8011.7721.7441.716
1.6881.6611.6351.6091.584
1.5591.5341.5101.4871.464
1.4411.4191.3971.3751.354
1.3341.3131.2931.2741.254
1.2351.2171.1981.1801.163
1.1451.1281.1121.0951.0791.063
1.0471.0321.0171.0020.9870.973
37.5337.4837.4337.3737.32
37.2637.2137.1637.1137.05
37.0036.9536.8936.8436.78
36.7336.6736.6236.5636.51
36.4536.4036.3436.2936.23
36.1836.1236.0636.0135.95
35.9035.8435.7835.7235.67
35.6135.5535.4935.4335.3835.32
35.2635.2035.1435.0835.0234.96
130.8132.0133.1134.3135.4
136.6137.8138.9140.1141.2
142.4143.5144.7145.8147.0
148.2149.4150.5151.7152.9
154.0155.2156.4157.6158.7
159.9161.1162.3163.5164.6
165.8167.0168.2169.4170.6
171.8173.0174.2175.4176.6177.8
179.0180.2181.4182.6183.9185.1
630.5630.7630.8631.0631.1
631.3631.4631.5631.7631.8
631.9632.0632.1632.2632.3
632.5632.6632.6632.8632.9
632.9633.0633.1633.2633.3
633.4633.4633.5633.6633.6
633.7633.7633.8633.8633.9
633.9633.9634.0634.0634.0634.0
634.0634.0634.0634.0634.0634.0
0.2728.2749.2769.2791.2812
0.2833.2854.2875.2895.2917
0.2937.2958.2979.3000.3021
0.3041.3062.3083.3104.3125
0.3145.3166.3187.3207.3228
0.3248.3269.3289.3310.3330
0.3351.3372.3392.3413.3433
0.3453.3474.3495.3515.35353556
0.3576.3597.3618.3638.3659.3679
1.20061.19911.19761.19621.1947
1.19331.19181.19041.18891.1875
1.18601.18461.18321.18181.1804
1.17891.17751.17611.17471.1733
1.17191.17051.16911.16771.1663
1.16491.16351.16211.16071.1593
1.15801.15661.15521.15381.1524
1.15101.14971.14831.14691.14551.1441
1.14271.14141.14001.13861.13721.1358
1. Based on 0 for the saturated liquid at −40�F.2. Inches of mercury below one standard atmosphere.3. Standard cycle temperatures.
Chapter 10. Engineering Data
211
Properties of Water
Temperature(�F)
SaturationPressure
(Pounds PerSquare Inch
Absolute)
Weight(Pounds Per
Gallon)
SpecificGravity60/60 �F
ConversionFactor,(1)
lbs./hr.to GPM
32 .0885 8.345 1.0013 .00199
40 .1217 8.345 1.0013 .00199
50 .1781 8.340 1.0007 .00199
60 .2653 8.334 1.0000 .00199
70 .3631 8.325 .9989 .00200
80 .5069 8.314 .9976 .00200
90 .6982 8.303 .9963 .00200
100 .9492 8.289 .9946 .00201
110 1.2748 8.267 .9919 .00201
120 1.6924 8.253 .9901 .00201
130 2.2225 8.227 .9872 .00202
140 2.8886 8.207 .9848 .00203
150 3.718 8.182 .9818 .00203
160 4.741 8.156 .9786 .00204
170 5.992 8.127 .9752 .00205
180 7.510 8.098 .9717 .00205
190 9.339 8.068 .9681 .00206
200 11.526 8.039 .9646 .00207
210 14.123 8.005 .9605 .00208
212 14.696 7.996 .9594 .00208
220 17.186 7.972 .9566 .00209
240 24.969 7.901 .9480 .00210
260 35.429 7.822 .9386 .00211
280 49.203 7.746 .9294 .00215
300 67.013 7.662 .9194 .00217
350 134.63 7.432 .8918 .00224
400 247.31 7.172 .8606 .00232
450 422.6 6.892 .8270 .00241
500 680.8 6.553 .7863 .00254
550 1045.2 6.132 .7358 .00271
600 1542.9 5.664 .6796 .00294
700 3093.7 3.623 .4347 .004601. Multiply flow in pounds per hour by the factor to get equivalent flow in gallons per minute.Weight per gallon is based on 7.48 gallons per cubic foot.
Chapter 10. Engineering Data
212
Properties of Saturated Steam
ABSOLUTEPRESSURE VACUUM
(INCHESOF Hg)
TEMPER−ATURE
t(�F)
HEATOF THELIQUID
(BTU/LB)
LATENTHEAT
OFEVAPOR−
ATION(BTU/LB)
TOTALHEAT
OFSTEAM
Hg(BTU/LB)
SPECIFICVOLUME
�
(CU FTPER LB)
Lbs PerSq In.
P’
Inchesof Hg
0.200.250.300.350.400.45
0.500.600.700.800.90
1.01.21.41.61.8
2.02.22.42.62.8
3.03.54.04.55.0
5.56.06.57.07.5
8.08.59.09.510.0
11.012.013.014.0
0.410.510.610.710.810.92
1.021.221.431.631.83
2.042.442.853.263.66
4.074.484.895.295.70
6.117.138.149.16
10.18
11.2012.2213.2314.2515.27
16.2917.3118.3219.3420.36
22.4024.4326.4728.50
29.5129.4129.3129.2129.1129.00
28.9028.7028.4928.2928.09
27.8827.4827.0726.6626.26
25.8525.4425.0324.6324.22
23.8122.7921.7820.7619.74
18.7217.7016.6915.6714.65
13.6312.6111.6010.589.56
7.525.493.451.42
53.1459.3064.4768.9372.8676.38
79.5885.2190.0894.3898.24
101.74107.92113.26117.99122.23
126.08129.62132.89135.94138.79
141.48147.57152.97157.83162.24
166.30170.06173.56176.85179.94
182.86185.64188.28190.80193.21
197.75201.96205.88209.56
21.2127.3632.5236.9740.8944.41
47.6053.2158.0762.3666.21
69.7075.8781.2085.9190.14
93.9997.52100.79103.83106.68
109.37115.46120.86125.71130.13
134.19137.96141.47144.76147.86
150.79153.57156.22158.75161.17
165.73169.96173.91177.61
1063.81060.31057.41054.91052.71050.7
1048.81045.71042.91040.41038.3
1036.31032.71029.61026.91024.5
1022.21020.21018.31016.51014.8
1013.21009.61006.41003.61001.0
998.5996.2994.1992.1990.2
988.5986.8985.2983.6982.1
979.3976.6974.2971.9
1085.01087.71090.01091.91093.61095.1
1096.41098.91101.01102.81104.5
1106.01108.61110.81112.81114.6
1116.21117.71119.11120.31121.5
1122.61125.11127.31129.31131.1
1132.71134.21135.61136.91138.1
1139.31140.41141.41142.31143.3
1145.01146.61148.11149.5
1526.01235.31039.5898.5791.9708.5
641.4540.0466.9411.7368.4
333.6280.9243.0214.3191.8
173.73158.85146.38135.78126.65
118.71102.7290.6381.1673.52
67.2461.9857.5053.6450.29
47.3444.7342.4040.3138.42
35.1432.4030.0628.04
Chapter 10. Engineering Data
213
Properties of Saturated Steam
PRESSURE(LBS. PER SQ IN.)
TEMPER−ATURE
t(�F)
HEAT OFTHE
LIQUID(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
SPECIFICVOLUME �
(CU FTPER LB)Absolute P’ Gauge P
14.69615.016.017.018.019.0
20.021.022.023.024.0
25.026.027.028.029.0
30.031.032.033.034.0
35.036.037.038.039.0
40.041.042.043.044.0
45.046.047.048.049.0
50.051.052.053.054.0
0.00.31.32.33.34.3
5.36.37.38.39.3
10.311.312.313.314.3
15.316.317.318.319.3
20.321.322.323.324.3
25.326.327.328.329.3
30.331.332.333.334.3
35.336.337.338.339.3
212.00213.03216.32219.44222.41225.24
227.96230.57233.07235.49237.82
240.07242.25244.36246.41248.40
250.33252.22254.05255.84257.58
259.28260.95262.57264.16265.72
267.25268.74270.21271.64273.05
274.44275.80277.13278.45279.74
281.01282.26283.49284.70285.90
180.07181.11184.42187.56190.56193.42
196.16198.79201.33203.78206.14
208.42210.62212.75214.83216.86
218.82220.73222.59224.41226.18
227.91229.60231.26232.89234.48
236.03237.55239.04240.51241.95
243.36244.75246.12247.47248.79
250.09251.37252.63253.87255.09
970.3969.7967.6965.5963.6961.9
960.1958.4956.8955.2953.7
952.1950.7949.3947.9946.5
945.3944.0942.8941.6940.3
939.2938.0936.9935.8934.7
933.7932.6931.6930.6929.6
928.6927.7926.7925.8924.9
924.0923.0922.2921.3920.5
1150.41150.81152.01153.11154.21155.3
1156.31157.21158.11159.01159.8
1160.61161.31162.01162.71163.4
1164.11164.71165.41166.01166.5
1167.11167.61168.21168.71169.2
1169.71170.21170.71171.11171.6
1172.01172.41172.91173.31173.7
1174.11174.41174.81175.21175.6
26.8026.2924.7523.3922.1721.08
20.08919.19218.37517.62716.938
16.30315.71515.17014.66314.189
13.74613.33012.94012.57212.226
11.89811.58811.29411.01510.750
10.49810.25810.0299.8109.601
9.4019.2099.0258.8488.678
8.5158.3598.2088.0627.922
(continued)
Chapter 10. Engineering Data
214
Properties of Saturated Steam (continued)
PRESSURE(LBS. PER SQ IN.)
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Absolute P’
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Gauge P
55.056.057.058.059.0
60.061.062.063.064.0
65.066.067.068.069.0
70.071.072.073.074.0
75.076.077.078.079.0
80.081.082.083.084.0
85.086.087.088.089.0
90.091.092.093.094.0
95.096.097.098.099.0
40.341.342.343.344.3
45.346.347.348.349.3
50.351.352.353.354.3
55.356.357.358.359.3
60.361.362.363.364.3
65.366.367.368.369.3
70.371.372.373.374.3
75.376.377.378.379.3
80.381.382.383.384.3
287.07288.23289.37290.50291.61
292.71293.79294.85295.90296.94
297.97298.99299.99300.98301.96
302.92303.88304.83305.76306.68
307.60308.50309.40310.29311.16
312.03312.89313.74314.59315.42
316.25317.07317.88318.68319.48
320.27321.06321.83322.60323.36
324.12324.87325.61326.35327.08
256.30257.50258.67259.82260.96
262.09263.20264.30265.38266.45
267.50268.55269.58270.60291.61
272.61273.60274.57275.54276.49
277.43278.37279.30280.21281.12
282.02282.91283.79284.66285.53
286.39287.24288.08288.91289.74
290.56291.38292.18292.98293.78
294.56295.34296.12296.89297.65
919.6918.8917.9917.1916.3
915.5914.7913.9913.1912.3
911.6910.8910.1909.4908.7
907.9907.2906.5905.8905.1
904.5903.7903.1902.4901.7
901.1900.4899.7899.1898.5
897.8897.2896.5895.9895.3
894.7894.1893.5892.9892.3
891.7891.1890.5889.9889.4
1175.91176.31176.61176.91177.3
1177.61177.91178.21178.51178.8
1179.11179.41179.71180.01180.3
1180.61180.81181.11181.31181.6
1181.91182.11182.41182.61182.8
1183.11183.31183.51183.81184.0
1184.21184.41184.61184.81185.1
1185.31185.51185.71185.91186.1
1186.21186.41186.61186.81187.0
7.7877.6567.5297.4077.289
7.1757.0646.9576.8536.752
6.6556.5606.4686.3786.291
6.2066.1246.0445.9665.890
5.8165.7435.6735.6045.537
5.4725.4085.3465.2855.226
5.1685.1115.0555.0014.948
4.8964.8454.7964.7474.699
4.6524.6064.5614.5174.474
(continued)
Chapter 10. Engineering Data
215
Properties of Saturated Steam (continued)
PRESSURE(LBS. PER SQ IN.)
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Absolute P’
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Gauge P
100.0101.0102.0103.0104.0
105.0106.0107.0108.0109.0
110.0111.0112.0113.0114.0
115.0116.0117.0118.0119.0
120.0121.0122.0123.0124.0
125.0126.0127.0128.0129.0
130.0131.0132.0133.0134.0
135.0136.0137.0138.0139.0
140.0141.0142.0143.0144.0
85.386.387.388.389.3
90.391.392.393.394.3
95.396.397.398.399.3
100.3101.3102.3103.3104.3
105.3106.3107.3108.3109.3
110.3111.3112.3113.3114.3
115.3116.3117.3118.3119.3
120.3121.3122.3123.3124.3
125.3126.3127.3128.3129.3
327.81328.53329.25329.96330.66
331.36332.05332.74333.42334.10
334.77335.44336.11336.77337.42
338.07338.72339.36339.99340.62
341.25341.88342.50343.11343.72
344.33344.94345.54346.13346.73
347.32347.90348.48349.06349.64
350.21350.78351.35351.91352.47
353.02353.57354.12354.67355.21
298.40299.15299.90300.64301.37
302.10302.82303.54304.26304.97
305.66306.37307.06307.75308.43
309.11309.79310.46311.12311.78
312.44313.10313.75314.40315.04
315.68316.31316.94317.57318.19
318.81319.43320.04320.65321.25
321.85322.45323.05323.64324.23
324.82325.40325.98326.56327.13
888.8888.2887.6887.1886.5
886.0885.4884.9884.3883.7
883.2882.6882.1881.6881.1
880.6880.0879.5879.0878.4
877.9877.4876.9876.4875.9
875.4874.9874.4873.9873.4
872.9872.5872.0871.5871.0
870.6870.1869.6869.1868.7
868.2867.7867.2866.7866.3
1187.21187.41187.51187.71187.9
1188.11188.21188.41188.61188.7
1188.91189.01189.21189.41189.5
1189.71189.81190.01190.11190.2
1190.41190.51190.71190.81190.9
1191.11191.21191.31191.51191.6
1191.71191.91192.01192.11192.2
1192.41192.51192.61192.71192.9
1193.01193.11193.21193.31193.4
4.4324.3914.3504.3104.271
4.2324.1944.1574.1204.084
4.0494.0153.9813.9473.914
3.8823.8503.8193.7883.758
3.7283.6993.6703.6423.614
3.5873.5603.5333.5073.481
3.4553.4303.4053.3813.357
3.3333.3103.2873.2643.242
3.2203.1983.1773.1553.134
(continued)
Chapter 10. Engineering Data
216
Properties of Saturated Steam (continued)
PRESSURE(LBS. PER SQ IN.)
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Absolute P’
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Gauge P
145.0146.0147.0148.0149.0
150.0152.0154.0156.0158.0
160.0162.0164.0166.0168.0
170.0172.0174.0176.0178.0
180.0182.0184.0186.0188.0
190.0192.0194.0196.0198.0
200.0205.0210.0215.0220.0
225.0230.0235.0240.0245.0
250.0255.0260.0265.0270.0
130.3131.3132.3133.3134.3
135.3137.3139.3141.3143.3
145.3147.3149.3151.3153.3
155.3157.3159.3161.3163.3
165.3167.3169.3171.3173.3
175.3177.3179.3181.3183.3
185.3190.3195.3200.3205.3
210.3215.3220.3225.3230.3
235.3240.3245.3250.3255.3
355.76356.29356.83357.36357.89
358.42359.46360.49361.52362.53
363.53364.53365.51366.48367.45
368.41369.35370.29371.22372.14
373.06373.96374.86375.75376.64
377.51378.38379.24380.10380.95
381.79383.86385.90387.89389.86
391.79393.68395.54397.37399.18
400.95402.70404.42406.11407.78
327.70328.27328.83329.39329.95
330.51331.61332.70333.79334.86
335.93336.98338.02339.05340.07
341.09342.10343.10344.09345.06
346.03347.00347.96348.92349.86
350.79351.72352.64353.55354.46
355.36357.58359.77361.91364.02
366.09368.13370.14372.12374.08
376.00377.89379.76381.60383.42
865.8865.3864.9864.5864.0
863.6862.7861.8860.9860.0
859.2858.3857.5856.6855.7
854.9854.1853.3852.4851.6
850.8850.0849.2848.4847.6
846.8846.1845.3844.5843.7
843.0841.1839.2837.4835.6
833.8832.0830.3828.5826.8
825.1823.4821.8820.1818.5
1193.51193.61193.81193.91194.0
1194.11194.31194.51194.71194.9
1195.11195.31195.51195.71195.8
1196.01196.21196.41196.51196.7
1196.91197.01197.21197.31197.5
1197.61197.81197.91198.11198.2
1198.41198.71199.01199.31199.6
1199.91200.11200.41200.61200.9
1201.11201.31201.51201.71201.9
3.1143.0943.0743.0543.034
3.0152.9772.9402.9042.869
2.8342.8012.7682.7362.705
2.6752.6452.6162.5872.559
2.5322.5052.4792.4542.429
2.4042.3802.3562.3332.310
2.2882.2342.1832.1342.087
2.04221.99921.95791.91831.8803
1.84381.80861.77481.74221.7107
(continued)
Chapter 10. Engineering Data
217
Properties of Saturated Steam (continued)
PRESSURE(LBS. PER SQ IN.)
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Absolute P’
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Gauge P
275.0280.0285.0290.0295.0
300.0320.0340.0360.0380.0
400.0420.0440.0460.0480.0
500.0520.0540.0560.0580.0
600.0620.0640.0660.0680.0
700.0720.0740.0760.0780.0
800.0820.0840.0860.0880.0
900.0920.0940.0960.0980.0
1000.01050.01100.01150.01200.0
260.3265.3270.3275.3280.3
285.3305.3325.3345.3365.3
385.3405.3425.3445.3465.3
485.3505.3525.3545.3565.3
585.3605.3625.3645.3665.3
685.3705.3725.3745.3765.3
785.3805.3825.3845.3865.3
885.3905.3925.3945.3965.3
985.31035.31085.31135.31185.3
409.43411.05412.65414.23415.79
417.33423.29428.97434.40439.60
444.59449.39454.02458.50462.82
467.01471.07475.01478.85482.58
486.21489.75493.21496.58499.88
503.10506.25509.34512.36515.33
518.23521.08523.88526.63529.33
531.98534.59537.16539.68542.17
544.61550.57556.31561.86567.22
385.21386.98388.73390.46392.16
393.84400.39406.66412.67418.45
424.0429.4434.6439.7444.6
449.4454.1458.6463.0467.4
471.6475.7479.8483.8487.7
491.5495.3499.0502.6506.2
509.7513.2516.6520.0523.3
526.6529.8533.0536.2539.3
542.4550.0557.4564.6571.7
816.9815.3813.7812.1810.5
809.0803.0797.1791.4785.8
780.5775.2770.0764.9759.9
755.0750.1745.4740.8736.1
731.6727.2722.7718.3714.0
709.7705.4701.2697.1692.9
688.9684.8680.8676.8672.8
668.8664.9661.0657.1653.3
649.4639.9630.4621.0611.7
1202.11202.31202.41202.61202.7
1202.81203.41203.71204.11204.3
1204.51204.61204.61204.61204.5
1204.41204.21204.01203.81203.5
1203.21202.91202.51202.11201.7
1201.21200.71200.21199.71199.1
1198.61198.01197.41196.81196.1
1195.41194.71194.01193.31192.6
1191.81189.91187.81185.61183.4
1.68041.65111.62281.59541.5689
1.54331.44851.36451.28951.2222
1.16131.10611.05561.00940.9670
0.92780.89150.85780.82650.7973
0.76980.74400.71980.69710.6757
0.65540.63620.61800.60070.5843
0.56870.55380.53960.52600.5130
0.50060.48860.47720.46630.4557
0.44560.42180.40010.38020.3619
(continued)
Chapter 10. Engineering Data
218
Properties of Saturated Steam (continued)
PRESSURE(LBS. PER SQ IN.)
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Absolute P’
SPECIFICVOLUME �
(CU FTPER LB)
TOTALHEAT OF
STEAM Hg(BTU/LB)
LATENTHEAT OFEVAPOR−
ATION(BTU/LB)
HEAT OFTHE
LIQUID(BTU/LB)
TEMPER−ATURE
t(�F)Gauge P
1250.01300.01350.01400.01450.0
1500.01600.01700.01800.01900.0
2000.02100.02200.02300.02400.0
2500.02600.02700.02800.02900.0
3000.03100.03200.03206.2
1235.31285.31335.31385.31435.3
1485.31585.31685.31785.31885.3
1985.32085.32185.32285.32385.3
2485.32585.32685.32785.32885.3
2985.33085.33185.33191.5
572.42577.46582.35587.10591.73
596.23604.90613.15621.03628.58
635.82642.77649.46655.91662.12
668.13673.94679.55684.99690.26
695.36700.31705.11705.40
578.6585.4592.1598.7605.2
611.6624.1636.3648.3660.1
671.7683.3694.8706.5718.4
730.6743.0756.2770.1785.4
802.5825.0872.4902.7
602.4593.2584.0574.7565.5
556.3538.0519.6501.1482.4
463.4444.1424.4403.9382.7
360.5337.2312.1284.7253.6
217.8168.162.00.0
1181.01178.61176.11173.41170.7
1167.91162.11155.91149.41142.4
1135.11127.41119.21110.41101.1
1091.11080.21068.31054.81039.0
1020.3993.1934.4902.7
0.34500.32930.31480.30120.2884
0.27650.25480.23540.21790.2021
0.18780.17460.16250.15130.1407
0.13070.12130.11230.10350.0947
0.08580.07530.05800.0503
Ch
apter 10. E
ng
ineerin
g D
ata
219
Properties of Superheated Steam � = specific volume, cubic feet per pound
hg = total heat of steam, Btu per poundPRESSURE
(LBS PER SQ IN) SAT.TEMP.
t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 360� 400� 440� 480� 500� 600� 700� 800� 900� 1000� 1200�
14.696 0.0 212.00 �
hg
33.031221.1
34.681239.9
36.321258.8
37.961277.6
38.781287.1
42.861334.8
46.941383.2
51.001432.3
55.071482.3
59.131533.1
67.251637.5
20.0 5.3 227.96 �
hg
24.211220.3
25.431239.2
26.651258.2
27.861277.1
28.461286.6
31.471334.4
34.471382.9
37.461432.1
40.451482.1
43.441533.0
49.411637.4
30.0 15.3 250.33 �
hg
16.0721218.6
16.8971237.9
17.7141257.0
18.5281276.2
18.9331285.7
20.951333.8
22.961382.4
24.961431.7
26.951481.8
28.951532.7
32.931637.2
40.0 25.3 267.25 �
hg
12.0011216.9
12.6281236.5
13.2471255.9
13.8621275.2
14.1681284.8
15.6881333.1
17.1981381.9
18.7021431.3
20.201481.4
21.701532.4
24.691637.0
50.0 35.3 281.01 �
hg
9.5571215.2
10.0651235.1
10.5671254.7
11.0621274.2
11.3091283.9
12.5321332.5
13.7441381.4
14.9501430.9
16.1521481.1
17.3521532.1
19.7471636.8
60.0 45.3 292.71 �
hg
7.9271213.4
8.3571233.6
8.7791253.5
9.1961273.2
9.4031283.0
10.4271331.8
11.4411380.9
12.4491430.5
13.4521480.8
14.4541531.9
16.4511636.6
70.0 55.3 302.92 �
hg
6.7621211.5
7.1361232.1
7.5021252.3
7.8631272.2
8.0411282.0
8.9241331.1
9.7961380.4
10.6621430.1
11.5241480.5
12.3831531.6
14.0971636.3
80.0 65.3 312.03 �
hg
5.8881209.7
6.2201230.7
6.5441251.1
6.8621271.1
7.0201281.1
7.7971330.5
8.5621379.9
9.3221429.7
10.0771480.1
10.8301531.3
12.3321636.2
90.0 75.3 320.27 �
hg
5.2081207.7
5.5081229.1
5.7991249.8
6.0841270.1
6.2251280.1
6.9201329.8
7.6031379.4
8.2791429.3
8.9521479.8
9.6231531.0
10.9591635.9
100.0 85.3 327.81 �
hg
4.6631205.7
4.9371227.6
5.2021248.6
5.4621269.0
5.5891279.1
6.2181329.1
6.8351378.9
7.4461428.9
8.0521479.5
8.6561530.8
9.8601635.7
− Continued −
Ch
apter 10. E
ng
ineerin
g D
ata
220 Properties of Superheated Steam (continued)� = specific volume, cubic feet per pound
hg = total heat of steam, Btu per poundPRESSURE
(LBS PER SQ IN) SAT.TEMP.
t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 360� 400� 440� 480� 500� 600� 700� 800� 900� 1000� 1200�
120.0 105.3 341.25 �
hg
3.8441201.6
4.0811224.4
4.3071246.0
4.5271266.90
4.6361277.2
5.1651327.7
5.6831377.8
6.1951428.1
6.7021478.8
7.2071530.2
8.2121635.3
140.0 125.3 353.02 �
hg
3.2581197.3
3.4681221.1
3.6671243.3
3.8601264.7
3.9541275.2
4.4131326.4
4.8611376.8
5.3011427.3
5.7381478.2
6.1721529.7
7.0351634.9
160.0 145.3 363.53 �
hg
- - -- - -
3.0081217.6
3.1871240.6
3.3591262.4
3.4431273.1
3.8491325.0
4.2441375.7
4.6311426.4
5.0151477.5
5.3961529.1
6.1521634.5
180.0 165.3 373.06 �
hg
- - -- - -
2.6491214.0
2.8131237.8
2.9691260.2
3.0441271.0
3.4111323.5
3.7641374.7
4.1101425.6
4.4521476.8
4.7921528.6
5.4661634.1
200.0 185.3 381.79 �
hg
- - -- - -
2.3611210.3
2.5131234.9
2.6561257.8
2.7261268.9
3.0601322.1
3.3801373.6
3.6931424.8
4.0021476.2
4.3091528.0
4.9171633.7
220.0 205.3 389.86 �
hg
- - -- - -
2.1251206.5
2.2671231.9
2.4001255.4
2.4651266.7
2.7721320.7
3.0661372.6
3.3521424.0
3.6341475.5
3.9131527.5
4.4671633.3
240.0 225.3 397.37 �
hg
- - -- - -
1.92761202.5
2.0621228.8
2.1871253.0
2.2471264.5
2.5331319.2
2.8041371.5
3.0681423.2
3.3271474.8
3.5841526.9
4.0931632.9
260.0 245.3 404.42 �
hg
- - -- - -
- - -- - -
1.88821225.7
2.0061250.5
2.0631262.3
2.3301317.7
2.5821370.4
2.8271422.3
3.0671474.2
3.3051526.3
3.7761632.5
280.0 265.3 411.05 �
hg
- - -- - -
- - -- - -
1.73881222.4
1.85121247.9
1.90471260.0
2.1561316.2
2.3921369.4
2.6211421.5
2.8451473.5
3.0661525.8
3.5041632.1
300.0 285.3 417.33 �
hg
- - -- - -
- - -- - -
1.60901219.1
1.71651245.3
1.76751257.6
2.0051314.7
2.2271368.3
2.4421420.6
2.6521472.8
2.8591525.2
3.2691631.7
− Continued −
Ch
apter 10. E
ng
ineerin
g D
ata
221
Properties of Superheated Steam (continued)� = specific volume, cubic feet per pound
hg = total heat of steam, Btu per poundPRESSURE
(LBS PER SQ IN) SAT.TEMP.
t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 360� 400� 440� 480� 500� 600� 700� 800� 900� 1000� 1200�
320.0 305.3 423.29 �
hg
- - -- - -
- - -- - -
1.49501215.6
1.59851242.6
1.64721255.2
1.87341313.2
2.0831367.2
2.2851419.8
2.4831472.1
2.6781524.7
3.0631631.3
340.0 325.3 428.97 �
hg
- - -- - -
- - -- - -
1.39411212.1
1.49411239.9
1.54101252.8
1.75691311.6
1.95621366.1
2.1471419.0
2.3341471.5
2.5181524.1
2.8811630.9
360.0 345.3 434.40 �
hg
- - -- - -
- - -- - -
1.30411208.4
1.40121237.1
1.44641250.3
1.65331310.1
1.84311365.0
2.0251418.1
2.2021470.8
2.3761523.5
2.7191630.5
− Continued −
Ch
apter 10. E
ng
ineerin
g D
ata
222 Properties of Superheated Steam (continued)� = specific volume, cubic feet per poundhg = total heat of steam, Btu per pound
PRESSURE(LBS PER SQ IN) SAT.
TEMP.t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 500� 540� 600� 640� 660� 700� 740� 800� 900� 1000� 1200�
380.0 365.3 439.60 �
hg
1.36161247.7
1.4441273.1
1.56051308.5
1.63451331.0
1.67071342.0
1.74191363.8
1.81181385.3
1.91491417.3
2.0831470.1
2.2491523.0
2.5751630.0
400.0 385.3 444.59 �
hg
1.28511245.1
1.36521271.0
1.47701306.9
1.54801329.6
1.58271340.8
1.65081362.7
1.71771384.3
1.81611416.4
1.97671469.4
2.1341522.4
2.4451629.6
420.0 405.3 449.39 �
hg
1.21581242.5
1.29351268.9
1.40141305.3
1.46971328.3
1.50301339.5
1.56841361.6
1.63241383.3
1.72671415.5
1.88021468.7
2.0311521.9
2.3271629.2
440.0 425.3 454.02 �
hg
1.15261239.8
1.22821266.7
1.33271303.6
1.39841326.9
1.43061338.2
1.49341360.4
1.55491382.3
1.64541414.7
1.79251468.1
1.93681521.3
2.2201628.8
460.0 445.3 458.50 �
hg
1.09481237.0
1.16851264.5
1.26981302.0
1.33341325.4
1.36441336.9
1.42501359.3
1.48421381.3
1.57111413.8
1.71241467.4
1.85081520.7
2.1221628.4
480.0 465.3 462.82 �
hg
1.04171234.2
1.11381262.3
1.21221300.3
1.27371324.0
1.30381335.6
1.36221358.2
1.41931380.3
1.50311412.9
1.63901466.7
1.77201520.2
2.0331628.0
500.0 485.3 467.01 �
hg
0.99271231.3
1.06331260.0
1.15911298.6
1.21881322.6
1.24781334.2
1.30441357.0
1.35961379.3
1.44051412.1
1.57151466.0
1.69961519.6
1.95041627.6
520.0 505.3 471.07 �
hg
0.94731228.3
1.01661257.7
1.11011296.9
1.16811321.1
1.19621332.9
1.25111355.8
1.30451378.2
1.38261411.2
1.50911465.3
1.63261519.0
1.87431627.2
540.0 525.3 475.01 �
hg
0.90521225.3
0.97331255.4
1.06461295.2
1.12111319.7
1.14851331.5
1.20171354.6
1.25351377.2
1.32911410.3
1.45141464.6
1.57071518.5
1.80391626.8
560.0 545.3 478.85 �
hg
0.86591222.2
0.93301253.0
1.02241293.4
1.07751318.2
1.10411330.2
1.15581353.5
1.20601376.1
1.27941409.4
1.39781463.9
1.51321517.9
1.73851626.4
580.0 565.3 482.58 �
hg
0.82911219.0
0.89541250.5
0.98301291.7
1.03681316.7
1.06271328.8
1.13311352.3
1.16191375.1
1.23311408.6
1.34791463.2
1.45961517.3
1.67761626.0
600.0 585.3 486.21 �
hg
0.79471215.7
0.86021248.1
0.94631289.9
0.99881315.2
1.02411327.4
1.07321351.1
1.12071374.0
1.18991407.7
1.30131462.5
1.40961516.7
1.62081625.5
Ch
apter 10. E
ng
ineerin
g D
ata
223
Properties of Superheated Steam (continued)� = specific volume, cubic feet per pound
hg = total heat of steam, Btu per pound
PRESSURE(LBS PER SQ IN) SAT.
TEMP.t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 500� 540� 600� 640� 660� 700� 740� 800� 900� 1000� 1200�
620.0 605.3 489.75 �
hg
0.76241212.4
0.82721245.5
0.91181288.1
0.96331313.7
0.98801326.0
1.03581349.9
1.08211373.0
1.14941406.8
1.25771461.8
1.36281516.2
1.56761625.1
640.0 625.3 493.21 �
hg
0.73191209.0
0.79631243.0
0.87951286.2
0.92991312.2
0.95411324.6
1.00081348.6
1.04591371.9
1.11151405.9
1.21681461.1
1.31901515.6
1.51781624.7
660.0 645.3 496.58 �
hg
0.70321205.4
0.76701240.4
0.84911284.4
0.89851310.6
0.92221323.2
0.96791347.4
1.01191370.8
1.07591405.0
1.17841460.4
1.27781515.0
1.47091624.3
680.0 665.3 499.88 �
hg
0.67591201.8
0.73951237.7
0.82051282.5
0.86901309.1
0.89221321.7
0.93691346.2
0.98001369.8
1.04241404.1
1.14231459.7
1.23901514.5
1.42691623.9
700.0 685.3 503.10 �
hg
- - -- - -
0.71341235.0
0.79341280.6
0.84111307.5
0.86391320.3
0.90771345.0
0.94981368.7
1.01081403.2
1.10821459.0
1.20241513.9
1.38531623.5
750.0 735.3 510.86 �
hg
- - -- - -
0.65401227.9
0.73191275.7
0.77781303.5
0.79961316.6
0.84141341.8
0.88131366.0
0.93911400.9
1.03101457.2
1.11961512.4
1.29121622.4
800.0 785.3 518.23 �
hg
- - -- - -
0.60151220.5
0.67791270.7
0.72231299.4
0.74331312.9
0.78331338.6
0.82151363.2
0.87631398.6
0.96331455.4
1.04701511.0
1.20881621.4
850.0 835.3 525.26 �
hg
- - -- - -
0.55461212.7
0.63011265.5
0.67321295.2
0.69341309.0
0.73201335.4
0.76851360.4
0.82091396.3
0.90371453.6
0.98301509.5
1.13601620.4
900.0 885.3 531.98 �
hg
- - -- - -
0.51241204.4
0.58731260.1
0.62941290.9
0.64911305.1
0.68631332.1
0.72151357.5
0.77161393.9
0.85061451.8
0.92621508.1
1.07141619.3
950.0 935.3 538.42 �
hg
- - -- - -
0.47401195.5
0.54891254.6
0.59011286.4
0.60921301.1
0.64531328.7
0.67931354.7
0.72751391.6
0.80311450.0
0.87531506.6
1.01361618.3
1000.0 985.3 544.61 �
hg
- - -- - -
- - -- - -
0.51401248.8
0.55461281.9
0.57331297.0
0.60841325.3
0.64131351.7
0.68781389.2
0.76041448.2
0.82941505.1
0.96151617.3
− Continued −
Ch
apter 10. E
ng
ineerin
g D
ata
224 Properties of Superheated Steam (continued)� = specific volume, cubic feet per poundhg = total heat of steam, Btu per pound
PRESSURE(LBS PER SQ IN) SAT.
TEMP.t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 660� 700� 740� 760� 780� 800� 860� 900� 1000� 1100� 1200�
1100.0 1085.3 556.31 �
hg
0.51101288.5
0.54451318.3
0.57551345.8
0.59041358.9
0.60491371.7
0.61911384.3
0.66011420.8
0.68661444.5
0.75031502.2
0.81771558.8
0.87161615.2
1200.0 1185.3 567.22 �
hg
0.45861279.6
0.49091311.0
0.52061339.6
0.53471353.2
0.54841366.4
0.56171379.3
0.60031416.7
0.62501440.7
0.68431499.2
0.74121556.4
079671613.1
1300.0 1285.3 577.46 �
hg
0.41391270.2
0.44541303.4
0.47391333.3
0.48741347.3
0.50041361.0
0.51311374.3
0.54961412.5
0.57281437.0
0.62841496.2
0.68161553.9
0.73331611.0
1400.0 1385.3 587.10 �
hg
0.37531260.3
0.40621295.5
0.43381326.7
0.44681341.3
0.45931355.4
0.47141369.1
0.50611408.2
0.52811433.1
0.58051493.2
0.63051551.4
0.67891608.9
1500.0 1485.3 596.23 �
hg
0.34131249.8
0.37191287.2
0.39891320.0
0.41141335.2
0.42351349.7
0.43521363.8
0.46841403.9
0.48931429.3
0.53901490.1
0.58621548.9
0.63181606.8
1600.0 1585.3 604.90 �
hg
0.31121238.7
0.34171278.7
0.36821313.0
0.38041328.8
0.39211343.9
0.40341358.4
0.43531399.5
0.45531425.3
0.50271487.0
0.54741546.4
0.59061604.6
1700.0 1685.3 613.15 �
hg
0.28421226.8
0.31481269.7
0.34101305.8
0.35291322.3
0.36431337.9
0.37531352.9
0.40611395.0
0.42531421.4
0.47061484.0
0.51321543.8
0.55421602.5
1800.0 1785.3 621.03 �
hg
0.25971214.0
0.29071260.3
0.31661298.4
0.32841315.5
0.33951331.8
0.35021347.2
0.38011390.4
0.39861417.4
0.44211480.8
0.48281541.3
0.52181600.4
1900.0 1885.3 628.58 �
hg
0.23711200.2
0.26881250.4
0.29471290.6
0.30631308.6
0.31731325.4
0.32771341.5
0.35681385.8
0.37471413.3
0.41651477.7
0.45561538.8
0.49291598.2
2000.0 1985.3 635.82 �
hg
0.21611184.9
0.24891240.0
0.27481282.6
0.28631301.4
0.29721319.0
0.30741335.5
0.33581381.2
0.35321409.2
0.39351474.5
0.43111536.2
0.46681596.1
2100.0 2085.3 642.77 �
hg
0.19621167.7
0.23061229.0
0.25671274.3
0.26821294.0
0.27891312.3
0.28901329.5
0.31671376.4
0.33371405.0
0.37271471.4
0.40891533.6
0.44331593.9
2200.0 2185.3 649.46 �
hg
0.17681147.8
0.21351217.4
0.24001265.7
0.25141286.3
0.26211305.4
0.27211323.3
0.29941371.5
0.31591400.8
0.35381468.2
0.38371531.1
0.42181591.8
Ch
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225
Properties of Superheated Steam (continued)� = specific volume, cubic feet per pound
hg = total heat of steam, Btu per poundPRESSURE
(LBS PER SQ IN) SAT.TEMP.
t
TOTAL TEMPERATURE—DEGREES FAHRENHEIT (t)
AbsoluteP’
GaugeP 660� 700� 740� 760� 780� 800� 860� 900� 1000� 1100� 1200�
2300.0 2285.3 655.91 �
hg
0.15751123.8
0.19781204.9
0.22471256.7
0.23621278.4
0.24681298.4
0.25671316.9
0.28351366.6
0.29971396.5
0.33651464.9
0.37031528.5
0.40231589.6
2400.0 2385.3 662.12 �
hg
- - -- - -
0.18281191.5
0.21051247.3
0.22211270.2
0.23271291.1
0.24251310.3
0.26891361.6
0.28481392.2
0.32071461.7
0.35341525.9
0.38431587.4
2500.0 2485.3 668.13 �
hg
- - -- - -
0.16861176.8
0.19731237.6
0.20901261.8
0.21961283.6
0.22941303.6
0.25551356.5
0.27101387.8
0.30611458.4
0.33791523.2
0.36781585.3
2600.0 2585.3 673.94 �
hg
- - -- - -
0.15491160.6
0.18491227.3
0.19671252.9
0.20741275.8
0.21721296.8
0.24311351.4
0.25841383.4
0.29261455.1
0.32361520.6
0.35261583.1
2700.0 2685.3 679.55 �
hg
- - -- - -
0.14151142.5
0.17321216.5
0.18531243.8
0.19601267.9
0.20591289.7
0.23151346.1
0.24661378.9
0.28011451.8
0.31031518.0
0.33851580.9
2800.0 2785.3 684.99 �
hg
- - -- - -
0.12811121.4
0.16221205.1
0.17451234.2
0.18541259.6
0.19531282.4
0.22081340.8
0.23561374.3
0.26851448.5
0.29791515.4
0.32541578.7
2900.0 2885.3 690.26 �
hg
- - -- - -
0.11431095.9
0.15171193.0
0.16441224.3
0.17541251.1
0.18531274.9
0.21081335.3
0.22541369.7
0.25771445.1
0.28641512.7
0.31321576.5
3000.0 2985.3 695.36 �
hg
- - -- - -
0.09841060.7
0.14161180.1
0.15481213.8
0.16601242.2
0.17601267.2
0.20141329.7
0.21591365.0
0.24761441.8
0.27571510.0
0.30181574.3
3100.0 3085.3 700.31 �
hg
- - -- - -
- - -- - -
0.13201166.2
0.14561202.9
0.15711233.0
0.16721259.3
0.19261324.1
0.20701360.3
0.23821438.4
0.26571507.4
0.29111572.1
3200.0 3185.3 705.11 �
hg
- - -- - -
- - -- - -
0.12261151.1
0.13691191.4
0.14861223.5
0.15891251.1
0.18431318.3
0.19861355.5
0.22931434.9
0.25631504.7
0.28111569.9
3206.2 3191.5 705.40 �
hg
- - -- - -
- - -- - -
0.12201150.2
0.13631190.6
0.14801222.9
0.15831250.5
0.18381317.9
0.19811355.2
0.22881434.7
0.25571504.5
0.28061569.8
Chapter 10. Engineering Data
226
Velocity of Liquids in Pipe
The mean velocity of any flowing liq-uid can be calculated from the follow-ing formula or from the nomograph onthe opposite page. The nomograph isa graphical solution of the formula.
v � 183.3qd2
� 0.408 Qd2
� 0.0509 Wd2 p
(For values of d, see Pipe Data Car-bon and Alloy Steel−Stainless Steeltable in Chapter 11.)
The pressure drop per 100 feet andthe velocity in Schedule 40 pipe, forwater at 60�F, have been calculatedfor commonly used flow rates for pipesizes of 1/8 to 24−inch; these valuesare tabulated on following pages.
Example 1
Given: No. 3 Fuel Oil of 0.898 specificgravity at 60�F flows through a 2−inchSchedule 40 pipe at the rate of 45,000pounds per hour.
Find: The rate of flow in gallons perminute and the mean velocity in thepipe.
Solution:
p = 56.02 = weight density inpounds per cubic foot (specificgravity of fluid times weight den-sity of water at same tempera-ture.)
Connect Read
W = 45,000 p = 56.02 Q = 100
Q = 100 2” Sched 40 v = 10
Example 2
Given: Maximum flow rate of a liquidwill be 300 gallons per minute withmaximum velocity limited to 12 feetper second through Schedule 40 pipe.
Find: The smallest suitable pipe sizeand the velocity through the pipe.
Solution:
Connect Read
Q = 300 v = 12 d = 3.2
3−1/2” Schedule 40 pipe suitable
Q = 300 3−1/2” Sched 40 v = 10
Reasonable Velocities for the Flowof Water through Pipe
Service ConditionReasonable
Velocity(feet per second)
Boiler FeedPump Suction and Drain LinesGeneral ServiceCity
8 to 15
4 to 74 to 10
to 7
Extracted from Technical Paper No.410, Flow of Fluids, with permission ofCrane Co.
Chapter 10. Engineering Data
227
Ch
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228 Flow of Water Through Schedule 40 Steel Pipe
DISCHARGE PRESSURE DROP PER 100 FEET AND VELOCITY IN SCHEDULE 40 PIPE FOR WATER AT 60�F
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Gallonsper
Minute
Cubic Ft.per
Second
1/8” 1/4”3/8” 1/2”
3/4”
1”1−1/4”
1−1/2”
.2 0.000446 1.13 1.86 0.616 0.359
.3 0.000668 1.69 4.22 0.924 0.903 0.504 0.159 0.317 0.061
.4 0.000891 2.26 6.98 1.23 1.61 0.672 0.345 0.422 0.086
.5 0.00111 2.82 10.5 1.54 2.39 0.840 0.539 0.528 0.167 0.301 0.033
.6 0.00134 3.39 14.7 1.85 3.29 1.01 0.751 0.633 0.240 0.361 0.041
.8 0.00178 4.52 25.0 2.46 5.44 1.34 1.25 0.844 0.408 0.481 0.102
1 0.00223 5.65 37.2 3.08 8.28 1.68 1.85 1.06 0.600 0.602 0.155 0.371 0.048
2 0.00446 11.29 134.4 6.16 30.1 3.36 6.58 2.11 2.10 1.20 0.526 0.743 0.164 0.429 0.044
3 0.00668
2”
9.25 64.1 5.04 13.9 3.17 4.33 1.81 1.09 1.114 0.336 0.644 0.090 0.473 0.043
4 0.00891 12.33 111.2 6.72 23.9 4.22 7.42 2.41 1.83 1.49 0.565 0.858 0.150 0.630 0.071
5 0.01114
2−1/2”
8.40 36.7 5.28 11.2 3.01 2.75 1.86 0.835 1.073 0.223 0.788 0.104
6 0.01337 0.574 0.044 10.08 51.9 6.33 15.8 3.61 3.84 2.23 1.17 1.29 0.309 0.946 0.145
8 0.01782 0.765 0.073 13.44 91.1 8.45 27.7 4.81 6.60 2.97 1.99 1.72 0.518 1.26 0.241
10 0.02228 0.956 0.108 0.670 0.0463”
10.56 42.4 6.02 9.99 3.71 2.99 2.15 0.774 1.58 0.361
15 0.03342 1.43 0.224 1.01 0.094
3−1/2”
9.03 21.6 5.57 6.36 3.22 1.63 2.37 0.755
20 0.04456 1.91 0.375 1.34 0.158 0.868 0.056 12.03 37.8 7.43 10.9 4.29 2.78 3.16 1.28
25 0.05570 2.39 0.561 1.68 0.234 1.09 0.083 0.812 0.041
4”9.28 16.7 5.37 4.22 3.94 1.93
30 0.06684 2.87 0.786 2.01 0.327 1.30 0.114 0.974 0.056 11.14 23.8 6.44 5.92 4.73 2.72
35 0.07798 3.35 1.05 2.35 0.436 1.52 0.151 1.14 0.071 0.882 0.041 12.99 32.2 7.51 7.90 5.52 3.64
40 0.08912 3.83 1.35 2.68 0.556 1.74 0.192 1.30 0.095 1.01 0.052 14.85 41.5 8.59 10.24 6.30 4.65
45 0.1003 4.30 1.67 3.02 0.668 1.95 0.239 1.46 0.117 1.13 0.064 9.67 12.80 7.09 5.85
(continued)
Ch
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229
Flow of Water Through Schedule 40 Steel Pipe (continued)
DISCHARGE PRESSURE DROP PER 100 FEET AND VELOCITY IN SCHEDULE 40 PIPE FOR WATER AT 60�FDISCHARGE
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Gallonsper
Minute
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Cubic Ft.per
Second
50 0.1114 4.78 2.03 3.35 0.839 2.17 0.288 1.62 0.142 1.26 0.0765”
10.74 15.66 7.88 7.15
60 0.1337 5.74 2.87 4.02 1.18 2.60 0.46 1.95 0.204 1.51 0.107 12.89 22.2 9.47 10.21
70 0.1560 6.70 3.84 4.69 1.59 3.04 0.540 2.27 0.261 1.76 0.143 1.12 0.047
6”
11.05 13.71
80 0.1782 7.65 4.97 5.36 2.03 3.47 0.687 2.60 0.334 2.02 0.180 1.28 0.060 12.62 17.59
90 0.2005 8.60 6.20 6.03 2.53 3.91 0.861 2.92 0.416 2.27 0.224 1.44 0.074 14.20 22.0
100 0.2228 9.56 7.59 6.70 3.09 4.34 1.05 3.25 0.509 2.52 0.272 1.60 0.090 1.11 0.036 15.78 26.9
125 0.2785 11.97 11.76 8.38 4.71 5.43 1.61 4.06 0.769 3.15 0.415 2.01 0.135 1.39 0.055 19.72 41.4
150 0.3342 14.36 16.70 10.05 6.69 6.51 2.24 4.87 1.08 3.78 0.580 2.41 0.190 1.67 0.077
8”
175 0.3899 16.75 22.3 11.73 8.97 7.60 3.00 5.68 1.44 4.41 0.774 2.81 0.253 1.94 0.102
200 0.4456 19.14 28.8 13.42 11.68 8.68 3.87 6.49 1.85 5.04 0.985 3.21 0.323 2.22 0.130
225 0.5013 − − − − − − 15.09 14.63 9.77 4.83 7.30 2.32 5.67 1.23 3.61 0.401 2.50 0.162 1.44 0.043
250 0.557 − − − − − − − − − − − − 10.85 5.93 8.12 2.84 6.30 1.46 4.01 0.495 2.78 0.195 1.60 0.051
275 0.6127 − − − − − − − − − − − − 11.94 7.14 8.93 3.40 6.93 1.79 4.41 0.583 3.05 0.234 1.76 0.061
300 0.6684 − − − − − − − − − − − − 13.00 8.36 9.74 4.02 7.56 2.11 4.81 0.683 3.33 0.275 1.92 0.072
325 0.7241 − − − − − − − − − − − − 14.12 9.89 10.53 4.09 8.19 2.47 5.21 0.797 3.61 0.320 2.08 0.083
350 0.7798
10”
− − − − − − − − − − − − 11.36 5.41 8.82 2.84 5.62 0.919 3.89 0.367 2.24 0.095
375 0.8355 − − − − − − − − − − − − 12.17 6.18 9.45 3.25 6.02 1.05 4.16 0.416 2.40 0.108
400 0.8912 − − − − − − − − − − − − 12.98 7.03 10.08 3.68 6.42 1.19 4.44 0.471 2.56 0.121
425 0.9469 − − − − − − − − − − − − 13.80 7.89 10.71 4.12 6.82 1.33 4.72 0.529 2.73 0.136
450 1.003 − − − − − − − − − − − − 14.61 8.80 11.34 4.60 7.22 1.48 5.00 0.590 2.89 0.151
475 1.059 1.93 0.054 − − − − − − − − − − − − 11.97 5.12 7.62 1.64 5.27 0.653 3.04 0.166
500 1.114 2.03 0.059 − − − − − − − − − − − − 12.60 5.65 8.02 1.81 5.55 0.720 3.21 0.182
(continued)
Ch
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230 Flow of Water Through Schedule 40 Steel Pipe (continued)
DISCHARGE PRESSURE DROP PER 100 FEET AND VELOCITY IN SCHEDULE 40 PIPE FOR WATER AT 60�FDISCHARGE
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Gallonsper
Minute
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Cubic Ft.per
Second
550 1.225 2.24 0.071
12”
− − − − − − − − − − − − 13.85 6.79 8.82 2.17 6.11 0.861 3.53 0.219
600 1.337 2.44 0.083 − − − − − − − − − − − − 15.12 8.04 9.63 2.55 6.66 1.02 3.85 0.258
650 1.448 2.64 0.097 − − − − − − − − − − − − − − − − − − 10.43 2.98 7.22 1.18 4.17 0.301
10” 5” 6” 8”
700 1.560 2.85 0.112 2.01 0.047
14”
− − − − − − − − − − − − 11.23 3.43 7.78 1.35 4.49 0.343
750 1.671 3.05 0.127 2.15 0.054 − − − − − − − − − − − − 12.03 3.92 8.33 1.55 4.81 0.392
800 1.782 3.25 0.143 2.29 0.061 − − − − − − − − − − − − 12.83 4.43 8.88 1.75 5.13 0.443
850 1.894 3.46 0.160 2.44 0.068 2.02 0.042 − − − − − − − − − − − − 13.64 5.00 9.44 1.96 5.45 0.497
900 2.005 3.66 0.179 2.58 0.075 2.13 0.047 − − − − − − − − − − − − 14.44 5.58 9.99 2.18 5.77 0.554
950 2.117 3.86 0.198 2.72 0.083 2.25 0.052
16”
− − − − − − 15.24 6.21 10.55 2.42 6.09 0.613
1000 2.228 4.07 0.218 2.87 0.091 2.37 0.057 − − − − − − 16.04 6.84 11.10 2.68 6.41 0.675
1100 2.451 4.48 0.260 3.15 0.110 2.61 0.068 − − − − − − 17.65 8.23 12.22 3.22 7.05 0.807
1200 2.674 4.88 0.306 3.44 0.128 2.85 0.080 2.18 0.042 − − − − − − − − − − − − 13.33 3.81 7.70 .948
1300 2.896 5.29 0.355 3.73 0.150 3.08 0.093 2.36 0.048 − − − − − − − − − − − − 14.43 4.45 8.33 1.11
1400 3.119 5.70 0.409 4.01 0.171 3.32 0.107 2.54 0.055
18”
20”
15.55 5.13 8.98 1.28
1500 3.342 6.10 0.466 4.30 0.195 3.56 0.122 2.72 0.063 16.66 5.85 9.62 1.46
1600 3.565 6.51 0.527 4.59 0.219 3.79 0.138 2.90 0.071 17.77 6.61 10.26 1.65
1800 4.010 7.32 0.663 5.16 0.276 4.27 0.172 3.27 0.088 2.58 0.050 19.99 8.37 11.54 2.08
2000 4.456 8.14 0.808 5.73 0.339 4.74 0.209 3.63 0.107 2.87 0.060 22.21 10.3 12.82 2.55
2500 5.570 10.17 1.24 7.17 0.515 5.93 0.321 4.54 0.163 3.59 0.091
24”
16.03 3.94
3000 6.684 12.20 1.76 8.60 0.731 7.11 0.451 5.45 0.232 4.30 0.129 3.46 0.075 19.24 5.59
3500 7.798 14.24 2.38 10.03 0.982 8.30 0.607 6.35 0.312 5.02 0.173 4.04 0.101 22.44 7.56
4000 8.912 16.27 3.08 11.47 1.27 9.48 0.787 7.26 0.401 5.74 0.222 4.62 0.129 3.19 0.052 25.65 9.80
4500 10.03 18.31 3.87 12.90 1.60 10.67 0.990 8.17 0.503 6.46 0.280 5.20 0.162 3.59 0.065 28.87 12.2
(continued)
Ch
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231
Flow of Water Through Schedule 40 Steel Pipe (continued)
DISCHARGE PRESSURE DROP PER 100 FEET AND VELOCITY IN SCHEDULE 40 PIPE FOR WATER AT 60�FDISCHARGE
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Gallonsper
Minute
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Press.Drop(PSI)
Velocity(Feetper
Sec.)
Cubic Ft.per
Second
5000 11.14 20.35 4.71 14.33 1.95 11.85 1.21 9.08 0.617 7.17 0.340 5.77 0.199 3.99 0.079 − − − − − −
6000 13.37 24.41 6.74 17.20 2.77 14.23 1.71 10.89 0.877 8.61 0.483 6.93 0.280 4.79 0.111 − − − − − −
7000 15.60 28.49 9.11 20.07 3.74 16.60 2.31 12.71 1.18 10.04 0.652 8.08 0.376 5.59 0.150 − − − − − −
8000 17.82 − − − − − − 22.93 4.84 18.96 2.99 14.52 1.51 11.47 0.839 9.23 0.488 6.38 0.192 − − − − − −
9000 20.05 − − − − − − 25.79 6.09 21.34 3.76 16.34 1.90 12.91 1.05 10.39 0.608 7.18 0.242 − − − − − −
10,000 22.28 − − − − − − 28.66 7.46 23.71 4.61 18.15 2.34 14.34 1.28 11.54 0.739 7.98 0.294 − − − − − −
12,000 26.74 − − − − − − 34.40 10.7 28.45 6.59 21.79 3.33 17.21 1.83 13.85 1.06 9.58 0.416 − − − − − −
14,000 31.19 − − − − − − − − − − − − 33.19 8.89 25.42 4.49 20.08 2.45 16.16 1.43 11.17 0.562 − − − − − −
16,000 35.65 − − − − − − − − − − − − − − − − − − 29.05 5.83 22.95 3.18 18.47 1.85 12.77 0.723 − − − − − −
18,000 40.10 − − − − − − − − − − − − − − − − − − 32.68 7.31 25.82 4.03 20.77 2.32 14.36 0.907 − − − − − −
20,000 44.56 − − − − − − − − − − − − − − − − − − 36.31 9.03 28.69 4.93 23.08 2.86 15.96 1.12 − − − − − −For pipe lengths other than 100 feet, the pressure drop is proportional to the length. Thus, for 50 feet of pipe, the pressure drop is approximately one−half the value given in the table—for 300 feet,three times the given value, etc.Velocity is a function of the cross sectional flow area; thus it is constant for a given flow rate and is independent of pipe length.
For calculations for pipe other than Schedule 40, see explanation later in this chapter.Extracted from Technical Paper No. 410, Flow of Fluids, with permission of Crane Co.
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Flow of Air Through Schedule 40 Steel Pipe FREE AIR
q’mCOMPRESSED
AIR PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
Cubic Feet PerMinute at 60�F and
14.7 psia
Cubic Feet PerMinute at 60�F and
100 psig
1/8” 1/4” 3/8”
1/2”
3/4”
1”
1−1/4”
1−1/2”
2”
1 0.128 0.361 0.083 0.018
2 0.256 1.31 0.285 0.064 0.020
3 0.384 3.06 0.605 0.133 0.042
4 0.513 4.83 1.04 0.226 0.071
5 0.641 7.45 1.58 0.343 0.106 0.027
6 0.769 10.6 2.23 0.408 0.148 0.037
8 1.025 18.6 3.89 0.848 0.255 0.062 0.019
10 1.282 28.7 5.96 1.26 0.356 0.094 0.029
15 1.922 − − − 13.0 2.73 0.834 0.201 0.062
20 2.563 − − − 22.8 4.76 1.43 0.345 0.102 0.026
25 3.204 − − − 35.6 7.34 2.21 0.526 0.156 0.039 0.019
30 3.845 − − − − − − 10.5 3.15 0.748 0.219 0.055 0.026
35 4.486 − − − − − − 14.2 4.24 1.00 0.293 0.073 0.035
40 5.126 − − − − − − 18.4 5.49 1.30 0.379 0.095 0.044
45 5.767 − − − − − − 23.1 6.90 1.62 0.474 0.116 0.055
50 6.408
2−1/2”
28.5 8.49 1.99 0.578 0.149 0.067 0.019
60 7.690 40.7 12.2 2.85 0.819 0.200 0.094 0.027
70 8.971 − − − 16.5 3.83 1.10 0.270 0.126 0.036
80 10.25 0.019 − − − 21.4 4.96 1.43 0.350 0.162 0.046
(continued)
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Flow of Air Through Schedule 40 Steel Pipe (continued)FREE AIR
q’m PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
COMPRESSEDAIR
Cubic Feet PerMinute at 60�F and
14.7 psia
PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
Cubic Feet PerMinute at 60�F and
100 psig
90 11.53 0.023
3”
− − − 27.0 6.25 1.80 0.437 0.203 0.058
100 12.82 0.029
3−1/2”
33.2 7.69 2.21 0.534 0.247 0.070
125 16.02 0.044 - - - 11.9 3.39 0.825 0.380 0.107
150 19.22 0.062 0.021 - - - 17.0 4.87 1.17 0.537 0.151
175 22.43 0.083 0.028 - - - 23.1 6.60 1.58 0.727 0.205
200 25.63 0.107 0.036 - - - 30.0 8.54 2.05 0.937 0.264
225 28.84 0.134 0.045 0.022
4”
37.9 10.8 2.59 1.19 0.331
250 32.04 0.164 0.055 0.027 - - - 13.3 3.18 1.45 0.404
275 35.24 0.191 0.066 0.032 - - - 16.0 3.83 1.75 0.484
300 38.45 0.232 0.078 0.037 - - - 19.0 4.56 2.07 0.573
325 41.65 0.270 0.090 0.043 - - - 22.3 5.32 2.42 0.673
350 44.87 0.313 0.104 0.050 - - - 25.8 6.17 2.80 0.776
375 48.06 0.356 0.119 0.057 0.030 - - - 29.6 7.05 3.20 0.887
400 51.26 0.402 0.134 0.064 0.034 - - - 33.6 8.02 3.64 1.00
425 54.47 0.452 0.151 0.072 0.038 - - - 37.9 9.01 4.09 1.13
450 57.67 0.507 0.168 0.081 0.042 - - - - - - 10.2 4.59 1.26
475 60.88 0.562 0.187 0.089 0.047
5”
- - - 11.3 5.09 1.40
500 64.08 0.623 0.206 0.099 0.052 - - - 12.5 5.61 1.55
550 70.49 0.749 0.248 0.118 0.062 - - - 15.1 6.79 1.87
600 76.90 0.887 0.293 0.139 0.073 - - - 18.0 8.04 2.21
650 83.30 1.04 0.342 0.163 0.086 - - - ‘21.1 9.43 2.60
700 89.71 1.19 0.395 0.188 0.099 0.032 24.3 10.9 3.00
(continued)
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234 Flow of Air Through Schedule 40 Steel Pipe (continued)FREE AIR
q’m PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
COMPRESSEDAIR
Cubic Feet PerMinute at 60�F and
14.7 psia
PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
Cubic Feet PerMinute at 60�F and
100 psig
750 96.12 1.36 0.451 0.214 0.113 0.036
6”
27.9 12.6 3.44
800 102.5 1.55 0.513 0.244 0.127 0.041 31.8 14.2 3.90
850 108.9 1.74 0.576 0.274 0.144 0.046 35.9 16.0 4.40
900 115.3 1.95 0.642 0.305 0.160 0.051 40.2 18.0 4.91
950 121.8 2.18 0.715 0.340 0.178 0.057 0.023 - - - 20.0 5.47
1,000 128.2 2.40 0.788 0.375 0.197 0.063 0.025 - - - 22.1 6.06
1,100 141.0 2.89 0.948 0.451 0.236 0.075 0.030 - - - 26.7 7.29
1,200 153.8 3.44 1.13 0.533 0.279 0.089 0.035 - - - 31.8 8.63
1,300 166.6 4.01 1.32 0.626 0.327 0.103 0.041 - - - 37.3 10.1
1,400 179.4 4.65 1.52 0.718 0.377 0.119 0.047
8”
10”
11.8
1,500 192.2 5.31 1.74 0.824 0.431 0.136 0.054 13.5
1,600 205.1 6.04 1.97 0.932 0.490 0.154 0.061 15.3
1,800 230.7 7.65 2.50 1.18 0.616 0.193 0.075 19.3
2,000 256.3 9.44 3.06 1.45 0.757 0.237 0.094 0.023 23.9
2,500 320.4 14.7 4.76 2.25 1.17 0.366 0.143 0.035 37.3
3,000 384.5 21.1 6.82 3.20 1.67 0.524 0.204 0.051 0.016
12”
3,500 448.6 28.8 9.23 4.33 2.26 0.709 0.276 0.068 0.022
4,000 512.6 37.6 12.1 5.66 2.94 0.919 0.358 0.088 0.028
4,500 576.7 47.6 15.3 7.16 3.69 1.16 0.450 0.111 0.035
5,000 640.8 - - - 18.8 8.85 4.56 1.42 0.552 0.136 0.043 0.018
6,000 769.0 - - - 27.1 12.7 6.57 2.03 0.794 0.195 0.061 0.025
7,000 897.1 - - - 36.9 17.2 8.94 2.76 1.07 0.262 0.082 0.034
(continued)
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Flow of Air Through Schedule 40 Steel Pipe (continued)FREE AIR
q’m PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
COMPRESSEDAIR
Cubic Feet PerMinute at 60�F and
14.7 psia
PRESSURE DROP OF AIR IN POUNDS PER SQUAREINCH PER 100 FEET OF SCHEDULE 40 PIPE
FOR AIR AT 100 POUNDS PER SQUARE INCHGAUGE PRESSURE AND 60�F TEMPERATURE
Cubic Feet PerMinute at 60�F and
100 psig
8,000 1025 - - - - - - 22.5 11.7 3.59 1.39 0.339 0.107 0.044
9,000 1153 - - - - - - 28.5 14.9 4.54 1.76 0.427 0.134 0.055
10,000 1282 - - - - - - 35.2 18.4 5.60 2.16 0.526 0.164 0.067
11,000 1410 - - - - - - - - - 22.2 6.78 2.62 0.633 0.197 0.081
12,000 1538 - - - - - - - - - 26.4 8.07 3.09 0.753 0.234 0.096
13,000 1666 - - - - - - - - - 31.0 9.47 3.63 0.884 0.273 0.112
14,000 1794 - - - - - - - - - 36.0 11.0 4.21 1.02 0.316 0.129
15,000 1922 - - - - - - - - - - - - 12.6 4.84 1.17 0.364 0.148
16,000 2051 - - - - - - - - - - - - 14.3 5.50 1.33 0.411 0.167
18,000 2307 - - - - - - - - - - - - 18.2 6.96 1.68 0.520 0.213
20,000 2563 - - - - - - - - - - - - 22.4 8.60 2.01 0.642 0.260
22,000 2820 - - - - - - - - - - - - 27.1 10.4 2.50 0.771 0.314
24,000 3076 - - - - - - - - - - - - 32.3 12.4 2.97 0.918 0.371
26,000 3332 - - - - - - - - - - - - 37.9 14.5 3.49 1.12 0.435
28,000 3588 - - - - - - - - - - - - - - - 16.9 4.04 1.25 0.505
30,000 3845 - - - - - - - - - - - - - - - 19.3 4.64 1.42 0.520
Chapter 10. Engineering Data
236
For lengths of pipe other than 100 feet, the pressure drop is proportional to thelength. Thus, for 50 feet of pipe, the pressure drop is approximately one−half thevalue given in the table—for 300 feet, three times the given value, etc.
The pressure drop is also inversely proportional to the absolute pressure anddirectly proportional to the absolute temperature.
Therefore, to determine the pressure drop for inlet or average pressures otherthan 100 psi and at temperatures other than 60�F, multiply the values given in thetable by the ratio:
�100 � 14.7P � 14.7
� �460 � t520
�
where:
P is the inlet or average gauge pressure in pounds per square inch, and,
t is the temperature in degrees Fahrenheit under consideration.
The cubic feet per minute of compressed air at any pressure is inversely propor-tional to the absolute pressure and directly proportional to the absolute tempera-ture.
To determine the cubic feet per minute of compressed air at any temperature andpressure other than standard conditions, multiply the value of cubic feet per min-ute of free air by the ratio:
� 14.714.7 � P
� �460 � t520
�
Calculations for Pipe Other than Schedule 40To determine the velocity of water, or the pressure drop of water or air, throughpipe other than Schedule 40, use to following formulas:
va � v40�d40
da�
2
�Pa � �P40�d40
da�
5
Subscript a refers to the Schedule of pipe through which velocity or pressuredrop is desired.
Subscript 40 refers to the velocity or pressure drop through Schedule 40 pipe, asgiven in the tables earlier in this chapter titled Flow of Water Through Schedule40 Steel Pipe.
Extracted from Technical Paper No. 410, Flow ofFluids, with permission of Crane Co.
237
Chapter 11
Pipe Data
Pipe EngagementLength of Thread on Pipe to Make a Tight Joint
NominalPipe Size(Inches)
DimensionA
(Inches)
NominalPipe Size(Inches)
DimensionA
(Inches)1/8 0.27 1−1/2 0.68
1/4 0.39 2 0.70
3/8 0.41 2−1/2 0.93
1/2 0.53 3 1.02
3/4 0.55 4 1.09
1 0.66 5 1.19
1−1/4 0.68 6 1.21Dimension A is the sum of L1 (handtight engagement) and L3 (wrench makeup length for internal thread) from ASMEB1.20.1−1992.
Ch
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238 Pipe Data Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
OUTSIDEDIAMETER
(Inches)
IDENTIFICATIONWALL
THICKNESS(t)
(INCHES)
INSIDEDIAMETER
(d)(INCHES)
AREAOF
METAL(SQUAREINCHES)
TRANSVERSEINTERNAL AREA WEIGHT
PIPE(LB/FT)
WATERWEIGHT(LB/FTPIPE)
Steel StainlessSteel
Sched.No.
IronPipeSize
Sched.No.
(a)(SquareInches)
(A)(Square
Feet)
1/8 0.405
– – –– – –STDXS
– – –304080
10S– – –40S80S
0.0490.0570.0680.095
0.3070.2910.2690.215
0.05480.06230.07200.0925
0.07400.06650.05680.0363
0.000510.000460.000390.00025
0.190.210.240.31
0.0320.0290.0250.016
1/4 0.540
– – –– – –STDXS
– – –304080
10S– – –40S80S
0.0650.0730.0880.119
0.4100.3940.3640.302
0.09700.10710.12500.1574
0.13200.12190.10410.0716
0.000920.000850.000720.00050
0.330.360.420.54
0.0570.0530.0450.031
3/8 0.675
– – –– – –STDXS
– – –304080
10S– – –40S80S
0.0650.0730.0910.126
0.5450.5290.4930.423
0.12460.13810.16700.2173
0.23330.21980.19090.1405
0.001620.001530.001330.00098
0.420.470.570.74
0.1010.0950.0830.061
1/2 0.840
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.0830.0950.1090.1470.1880.294
0.7100.6740.6500.6220.5460.4640.252
0.15830.19740.22230.25030.32000.38510.5043
0.39590.35680.33180.30390.23410.16910.0499
0.002750.002480.002300.002110.001630.001170.00035
0.540.670.760.851.091.311.71
0.1720.1550.1440.1320.1010.0730.022
(continued)
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239
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
3/4 1.050
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.0830.0950.1130.1540.2190.308
0.9200.8840.8600.8240.7420.6120.434
0.20110.25210.28500.33260.43350.57170.7180
0.66480.61380.58090.53330.43240.29420.1479
0.004620.004260.004030.003700.003000.002040.00103
0.690.860.971.131.471.942.44
0.2880.2660.2520.2310.1870.1270.064
1 1.315
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.1090.1140.1330.1790.2500.358
1.1851.0971.0871.0490.9570.8150.599
0.25530.41300.43010.49390.63880.83651.0763
1.1030.94520.92800.86430.71930.52170.2818
0.007660.006560.006440.006000.005000.003620.00196
0.871.401.461.682.172.843.66
0.4780.4100.4020.3750.3120.2260.122
1−1/4 1.660
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.1090.1170.1400.1910.2500.382
1.5301.4421.4261.3801.2781.1600.896
0.32570.53110.56720.66850.88151.10701.5340
1.8391.6331.5971.4961.2831.0570.6305
0.012770.011340.011090.010390.008910.007340.00438
1.111.811.932.273.003.765.21
0.7970.7080.6920.6480.5560.4580.273
(continued)
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240 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
1−1/2 1.900
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.1090.1250.1450.2000.2810.400
1.7701.6821.6501.6101.5001.3381.100
0.37470.61330.69700.79951.0681.4291.885
2.4612.2222.1382.0361.7671.4060.9503
0.017090.015430.014850.014140.012270.009760.00660
1.282.092.372.723.634.866.41
1.0660.9630.9270.8820.7660.6090.412
2 2.375
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0650.1090.1250.1540.2180.3440.436
2.2452.1572.1252.0671.9391.6871.503
0.47170.77600.88361.0751.4772.1952.656
3.9583.6543.5473.3562.9532.2351.774
0.027490.025380.024630.023300.020510.015520.01232
1.612.643.003.655.027.469.03
1.7151.5831.5371.4541.2800.9690.769
2−1/2 2.875
– – –– – –– – –STDXS
– – –XXS
– – –– – –
304080
160– – –
5S10S– – –40S80S– – –– – –
0.0830.1200.1880.2030.2760.3750.552
2.7092.6352.4992.4692.3232.1251.771
0.72801.0391.5871.7042.2542.9454.028
5.7645.4534.9054.7884.2383.5472.463
0.040030.037870.034060.033250.029430.024630.01711
2.483.535.405.797.66
10.0113.69
2.4982.3632.1252.0751.8371.5371.067
(continued)
Ch
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ata
241
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
3 3.500
– – –– – –
30STDXS
– – –XXS
– – –– – –– – –
4080
160– – –
5S10S– – –40S80S– – –– – –
0.0830.1200.1880.2160.3000.4380.600
3.3343.2603.1243.0682.9002.6242.300
0.89101.2741.9562.2283.0164.2135.466
8.7308.3477.6657.3936.6055.4084.155
0.060630.057960.053230.051340.045870.037550.02885
3.034.336.657.58
10.2514.3218.58
3.7833.6173.3223.2032.8622.3431.800
3−1/2 4.000
– – –– – –
30STDXS
– – –– – –– – –
4080
5S10S– – –40S80S
0.0830.1200.1880.2260.318
3.8343.7603.6243.5483.364
1.0211.4632.2512.6803.678
11.5511.1010.319.8878.888
0.080170.077110.071630.068660.06172
3.484.977.659.11
12.50
5.0034.8124.4704.2843.851
4 4.500
– – –– – –– – –STDXS
– – –– – –XXS
– – –– – –
304080
120160
– – –
5S10S– – –40S80S– – –– – –– – –
0.0830.1200.1880.2370.3370.4380.5310.674
4.3344.2604.1244.0263.8263.6243.4383.152
1.1521.6512.5473.1744.4075.5896.6218.101
14.7514.2513.3612.7311.5010.319.2837.803
0.102450.098980.092760.088400.079840.071630.064470.05419
3.925.618.66
10.7914.9819.0022.5127.54
6.3936.1765.7885.5164.9824.4704.0233.381
(continued)
Ch
apter 11. P
ipe D
ata
242 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
5 5.563
– – –– – –STDXS
– – –– – –XXS
– – –– – –
4080
120160
– – –
5S10S40S80S– – –– – –– – –
0.1090.1340.2580.3750.5000.6250.750
5.3455.2955.0474.8134.5634.3134.063
1.8682.2854.3006.1127.9539.696
11.34
22.4422.0220.0118.1916.3514.6112.97
0.155820.152920.138930.126350.113560.101460.09004
6.367.77
14.6220.7827.0432.9638.55
9.7239.5428.6697.8847.0866.3315.618
6 6.625
– – –– – –STDXS
– – –– – –XXS
– – –– – –
4080
120160
– – –
5S10S40S80S– – –– – –– – –
0.1090.1340.280.4320.5620.7190.864
6.4076.3576.0655.7615.5015.1874.897
2.2312.7335.5818.405
10.7013.3415.64
32.2431.7428.8926.0723.7721.1318.83
0.223890.220410.200630.181020.165050.146740.13079
7.609.29
18.9728.5736.3945.3553.16
13.9713.7512.5211.3010.309.1578.162
(continued)
Ch
apter 11. P
ipe D
ata
243
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
8 8.625
– – –– – –– – –– – –STD– – –XS
– – –– – –– – –XXS– – –
– – –– – –
2030406080
100120140
– – –160
5S10S– – –– – –40S– – –80S– – –– – –– – –– – –– – –
0.1090.1480.250.2770.3220.4060.50.5940.7190.8120.8750.906
8.4078.3298.1258.0717.9817.8137.6257.4377.1877.0016.8756.813
2.9163.9416.5787.2658.399
10.4812.7614.9917.8619.9321.3021.97
55.5154.4851.8551.1650.0347.9445.6643.4440.5738.5037.1236.46
0.385490.378370.360060.355290.347410.332940.317110.301660.281720.267330.257790.25317
9.9313.4022.3624.7028.5535.6443.3950.9560.7167.7672.4274.69
24.0523.6122.4722.1721.6820.7819.7918.8217.5816.6816.0915.80
10 10.750
– – –– – –– – –– – –STDXS
– – –– – –– – –XXS– – –
– – –– – –
2030406080
100120140160
5S10S– – –– – –40S80S– – –– – –– – –– – –– – –
0.1340.1650.2500.3070.3650.5000.5940.7190.8441.0001.125
10.48210.42010.25010.13610.0209.7509.5629.3129.0628.7508.500
4.4695.4878.247
10.0711.9116.1018.9522.6626.2730.6334.02
86.2985.2882.5280.6978.8574.6671.8168.1064.5060.1356.75
0.599260.592190.573030.560350.547600.518490.498680.472950.447900.417580.39406
15.1918.6528.0434.2440.4854.7464.4377.0389.29
104.13115.64
37.3936.9535.7634.9734.1732.3531.1229.5127.9526.0624.59
(continued)
Ch
apter 11. P
ipe D
ata
244 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
12 12.750
– – –– – –– – –– – –STD– – –XS
– – –– – –– – –XXS– – –– – –
– – –– – –
2030
– – –40
– – –6080
100120140160
5S10S– – –– – –40S– – –80S– – –– – –– – –– – –– – –– – –
0.1560.1800.2500.3300.3750.4060.5000.5620.6880.8441.0001.1251.312
12.43812.39012.25012.09012.00011.93811.75011.62611.37411.06210.75010.50010.126
6.1727.1089.818
12.8814.5815.7419.2421.5226.0731.5736.9141.0947.14
121.5120.6117.9114.8113.1111.9108.4106.2101.696.1190.7686.5980.53
0.843780.837280.818470.797230.785400.777310.753020.737210.705590.667410.630300.601320.55925
20.9824.1733.3843.7749.5653.5265.4273.1588.63
107.32125.49139.67160.27
52.6552.2551.0749.7549.0148.5046.9946.0044.0341.6539.3337.5234.90
(continued)
Ch
apter 11. P
ipe D
ata
245
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
14 14.000
– – –– – –– – –– – –STD– – –XS
– – –– – –– – –– – –– – –– – –
– – –– – –
10203040
– – –6080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.1560.1880.2500.3120.3750.4380.5000.5940.7500.9381.0941.2501.406
13.68813.62413.50013.37613.25013.12413.00012.81212.50012.12411.81211.50011.188
6.7858.158
10.8013.4216.0518.6621.2125.0231.2238.4944.3650.0755.63
147.2145.8143.1140.5137.9135.3132.7128.9122.7115.4109.6103.998.31
1.021901.012370.994020.975850.957550.939420.921750.895290.852210.801720.760980.721310.68271
23.0727.7336.7145.6154.5763.4472.0985.05
106.13130.85150.79170.21189.11
63.7763.1762.0360.8959.7558.6257.5255.8753.1850.0347.4945.0142.60
(continued)
Ch
apter 11. P
ipe D
ata
246 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
16 16.000
– – –– – –– – –– – –STDXS
– – –– – –– – –– – –– – –– – –
– – –– – –
102030406080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.1650.1880.2500.3120.3750.5000.6560.8441.0311.2191.4381.594
15.67015.62415.50015.37615.25015.00014.68814.31213.93813.56213.12412.812
8.2089.339
12.3715.3818.4124.3531.6240.1948.4856.6165.7972.14
192.9191.7188.7185.7182.7176.7169.4160.9152.6144.5135.3128.9
1.339261.331411.310361.289481.268431.227191.176671.117201.059571.003170.939420.89529
27.9031.7542.0552.2762.5882.77
107.50136.61164.82192.43223.64245.25
83.5783.0881.7780.4679.1576.5873.4269.7166.1262.6058.6255.87
(continued)
Ch
apter 11. P
ipe D
ata
247
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
18 18.000
– – –– – –– – –– – –STD– – –XS
– – –– – –– – –– – –– – –– – –– – –
– – –– – –
1020
– – –30
– – –406080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.1650.1880.2500.3120.3750.4380.5000.5620.7500.9381.1561.3751.5621.781
17.67017.62417.50017.37617.25017.12417.00016.87616.50016.12415.68815.25014.87614.438
9.24510.5213.9417.3420.7624.1727.4930.7940.6450.2861.1771.8280.6690.75
245.2243.9240.5237.1233.7230.3227.0223.7213.8204.2193.3182.7173.8163.7
1.702951.694091.670341.646751.622961.599331.576251.553341.484901.417991.342341.268431.206981.13695
31.4335.7647.3958.9470.5982.1593.45
104.67138.17170.92207.96244.14274.22308.50
106.3105.7104.2102.8101.399.8098.3696.9392.6688.4883.7679.1575.3270.95
(continued)
Ch
apter 11. P
ipe D
ata
248 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
20 20.000
– – –– – –– – –STDXS
– – –– – –– – –– – –– – –– – –– – –
– – –– – –
102030406080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.1880.2180.2500.3750.5000.5940.8121.0311.2811.5001.7501.969
19.62419.56419.50019.25019.00018.81218.37617.93817.43817.00016.50016.062
11.7013.5515.5123.1230.6336.2148.9561.4475.3387.18
100.3111.5
302.5300.6298.6291.0283.5277.9265.2252.7238.8227.0213.8202.6
2.100412.087582.073952.021111.968951.930181.841751.755001.658521.576251.484901.40711
39.7846.0652.7378.60
104.13123.11166.40208.87256.10296.37341.09379.17
131.1130.3129.4126.1122.9120.4114.9109.5103.598.3692.6687.80
22 22.000
– – –– – –– – –STDXS
– – –– – –– – –– – –– – –– – –
– – –– – –
1020306080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.1880.2180.2500.3750.5000.8751.1251.3751.6251.8752.125
21.62421.56421.50021.25021.00020.25019.75019.25018.75018.25017.750
12.8814.9217.0825.4833.7758.0773.7889.09
104.0118.5132.7
367.3365.2363.1354.7346.4322.1306.4291.0276.1261.6247.5
2.550352.536222.521192.462902.405292.236552.127472.021111.917481.816581.71840
43.8050.7158.0786.61
114.81197.41250.81302.88353.61403.00451.06
159.1158.3157.3153.7150.1139.6132.8126.1119.7113.4107.2
(continued)
Ch
apter 11. P
ipe D
ata
249
Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
24 24.000
– – –10
STDXS
– – –– – –– – –– – –– – –– – –– – –– – –
– – –– – –
20– – –
30406080
100120140160
5S10S– – –– – –– – –– – –– – –– – –– – –– – –– – –– – –
0.2180.2500.3750.5000.5620.6880.9691.2191.5311.8122.0622.344
23.56423.50023.25023.00022.87622.62422.06221.56220.93820.37619.87619.312
16.2918.6527.8336.9141.3850.3970.1187.24
108.1126.3142.1159.5
436.1433.7424.6415.5411.0402.0382.3365.1344.3326.1310.3292.9
3.028493.012062.948322.885252.854232.791692.654722.535752.391112.264472.154702.03415
55.3763.4194.62
125.49140.68171.29238.35296.58367.39429.39483.12542.13
189.0188.0184.0180.0178.1174.2165.7158.2149.2141.3134.5126.9
26 26.000– – –STDXS
10– – –
20
– – –– – –– – –
0.3120.3750.500
25.37625.25025.000
25.1830.1940.06
505.8500.7490.9
3.512163.477373.40885
85.60102.63136.17
219.2217.0212.7
28 28.000
– – –STDXS
– – –
10– – –
2030
– – –– – –– – –– – –
0.3120.3750.5000.625
27.37627.25027.00026.750
27.1432.5543.2053.75
588.6583.2572.6562.0
4.087604.050063.976093.90280
92.26110.64146.85182.73
255.1252.7248.1243.5
(continued)
Ch
apter 11. P
ipe D
ata
250 Pipe Data (continued)Carbon and Alloy Steel − Stainless Steel
Identification, wall thickness and weights are extracted from ASME B36.10M and B36.19M. The notations STD, XS and XXS indicateStandard, Extra Strong, and Double Extra Strong pipe, respectively.Transverse internal area values listed in “sq.ft” also represent volume in cubic feet per foot of pipe length.
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
IDENTIFICATION
OUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)
TRANSVERSEINTERNAL AREA
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
SteelOUTSIDEDIAMETER
(Inches)
NOMINALPIPESIZE
(INCHES)
WATERWEIGHT(LB/FTPIPE)
WEIGHTPIPE
(LB/FT)(A)
(SquareFeet)
(a)(SquareInches)
AREAOF
METAL(SQUAREINCHES)
INSIDEDIAMETER
(d)(INCHES)
WALLTHICKNESS
(t)(INCHES)
StainlessSteel
Sched.No.
Sched.No.
IronPipeSize
OUTSIDEDIAMETER
(Inches)
30 30.000
– – –10
STDXS
– – –
– – –– – –– – –
2030
5S10S– – –– – –– – –
0.2500.3120.3750.5000.625
29.50029.37629.25029.00028.750
23.3729.1034.9046.3457.68
683.5677.8672.0660.5649.2
4.746494.706674.666384.586954.50821
79.4398.93
118.65157.53196.08
296.2293.7291.2286.2281.3
32 32.000
– – –STDXS
– – –– – –
10– – –
203040
– – –– – –– – –– – –– – –
0.3120.3750.5000.6250.688
31.37631.25031.00030.75030.624
31.0637.2649.4861.6067.68
773.2767.0754.8742.6736.6
5.369375.326335.241455.157265.11508
105.59126.66168.21209.43230.08
335.0332.4327.1321.8319.2
34 34.000
– – –STDXS
– – –– – –
10– – –
203040
– – –– – –– – –– – –– – –
0.3120.3750.5000.6250.688
33.37633.25033.00032.75032.624
33.0239.6152.6265.5372.00
874.9868.3855.3842.4835.9
6.075716.029925.939595.849935.80501
112.25134.67178.89222.78244.77
379.1376.3370.6365.0362.2
36 36.000
– – –STDXS
– – –– – –
10– – –
203040
– – –– – –– – –– – –– – –
0.3120.3750.5000.6250.750
35.37635.25035.00034.75034.500
34.9841.9755.7669.4683.06
982.9975.9962.1948.4934.8
6.825686.777146.681356.586256.49182
118.92142.68189.57236.13282.35
425.9422.9416.9411.0405.1
Extracted from Technical Paper No. 410, Flow of Fluids, with permission of Crane Co.
Chapter 11. Pipe Data
251
American Pipe Flange DimensionsDiameter of Bolt Circle�Inches
Per ASME B16.1, B16.5, and B16.24
NominalPipeSize
Class(1)
125 (CastIron)(2)
or Class 150(Steel)
Class(3)
250 (CastIron)(2)
or Class 300(Steel)
Class600
Class900
Class1500
Class2500
11-1/41-1/2
22-1/2
3.123.503.884.755.50
3.503.884.505.005.88
3.503.884.505.005.88
4.004.384.886.507.50
4.004.384.886.507.50
4.255.125.756.757.75
34568
6.007.508.509.50
11.75
6.627.889.25
10.6213.00
6.628.50
10.5011.5013.75
7.509.25
11.0012.5015.50
8.009.50
11.5012.5015.50
9.0010.7512.7514.5017.25
1012141618
14.2517.0018.7521.2522.75
15.2517.7520.2522.5024.75
17.0019.2520.7523.7525.75
18.5021.0022.0024.2527.00
19.0022.5025.0027.7530.50
21.7524.38− − −− − −− − −
202430364248
25.0029.5036.0042.7549.5056.00
27.0032.0039.2546.0052.7560.75
28.5033.00− − −− − −− − −− − −
29.5035.50− − −− − −− − −− − −
32.7539.00
− − −− − −− − −− − −
− − −− − −− − −− − −− − −
1. Nominal pipe sizes 1 through 12 also apply to Class 150 cast copper alloy flanges.2. These diameters apply to steel valves for nominal pipe sizes 1 through 24.3. Nominal pipe sizes 1 thorough 8 also apply to Class 300 cast copper alloy flanges.
Ch
apter 11. P
ipe D
ata
252 American Pipe Flange DimensionsNumber of Stud Bolts and Diameter in Inches
Per ASME B16.1, B16.5, and B16.24
NOMINALPIPE SIZE
CLASS(1)
125 (CAST IRON)OR CLASS 150 (STEEL)(2)
CLASS(3)
250 (CAST IRON)OR CLASS 300
(STEEL)(2)
CLASS600
CLASS900
CLASS1500
CLASS2500
No. Dia. No. Dia. No. Dia. No. Dia. No. Dia. No. Dia.
11−1/41−1/222−1/2
44444
0.500.500.500.620.62
44488
0.620.620.750.620.75
44488
0.620.620.750.620.75
44488
0.880.881.000.881.00
44488
0.880.881.000.881.00
44488
0.881.001.121.001.12
34568
48888
0.620.620.750.750.75
888
1212
0.750.750.750.750.88
888
1212
0.750.881.001.001.12
888
1212
0.881.121.251.121.38
888
1212
1.121.251.501.381.62
8888
12
1.251.501.752.002.00
1012141618
1212121616
0.880.881.001.001.12
1616202024
1.001.121.121.251.25
1620202020
1.251.251.381.501.62
1620202020
1.381.381.501.621.88
1216161616
1.882.002.252.502.75
1212
...
...
...
2.502.75.........
202430364248
202028323644
1.121.251.251.501.501.50
242428323640
1.251.501.752.002.002.00
2424
...
...
...
...
1.621.88............
2020
...
...
...
...
2.002.50............
1616
...
...
...
...
3.003.50............
...
...
...
...
...
...
...
...
...
...
...
...1. Nominal pipe sizes 1 through 12 also apply to Class 150 cast copper alloy flanges.2. These diameters apply to steel valves for nominal pipe sizes 1 through 24.3. Nominal pipe sizes 1 through 8 also apply to Class 300 cast copper alloy flanges.
Chapter 11. Pipe Data
253
American Pipe Flange DimensionsFlange Diameter�Inches
Per ASME B16.1, B16.5, and B16.24
NominalPipe Size
Class(1)
125 (Cast Iron)or Class 150 (Steel)
Class(2)
250 (Cast Iron)or Class 300 (Steel)
Class600
Class900
Class1500
Class2500
11−1/41−1/2
22−1/2
4.254.625.006.007.00
4.885.256.126.507.50
4.885.256.126.507.50
5.886.257.008.509.62
5.886.257.008.509.62
6.257.258.009.25
10.50
34568
7.509.00
10.0011.0013.50
8.2510.0011.0012.5015.00
8.2510.7513.0014.0016.50
9.5011.5013.7515.0018.50
10.5012.2514.7515.5019.00
12.0014.0016.5019.0021.75
1012141618
16.0019.0021.0023.5025.00
17.5020.5023.0025.5028.00
20.0022.0023.7527.0029.25
21.5024.0025.2527.7531.00
23.0026.5029.5032.5036.00
26.5030.00
− − −− − −− − −
202430364248
27.5032.0038.7546.0053.0059.50
30.5036.0043.0050.0057.0065.00
32.0037.00
− − −− − −− − −− − −
33.7541.00
− − −− − −− − −− − −
38.7546.00
− − −− − −− − −− − −
− − −− − −− − −− − −− − −− − −
1. Nominal pipe sizes 1 through 12 also apply to Class 150 cast copper alloy flanges.2. Nominal pipe sizes 1 through 8 also apply to Class 300 cast copper alloy flanges.
Ch
apter 11. P
ipe D
ata
254 American Pipe Flange DimensionsFlange Thickness for Flange Fittings�Inches
Per ASME B16.1, B16.5 and B16.24
NOMINALPIPE SIZE
CLASS 150(CI) FF
CLASS 150(STL) RF
CLASS150
(STL)RTJ
CLASS 150CAST
COPPERALLOY
CLASS 250(CI) AND
CLASS 300(STL)(1)
CLASS 300(STL)
CLASS 300CAST
COPPERALLOY
CLASS600
CLASS900
CLASS1500
CLASS2500
RF RTJ RF RTJ RF RTJ RF RTJ RF RTJ
1 0.44 0.69 0.38 0.69 0.94 0.59 0.69 0.94 1.12 1.37 1.12 1.37 1.38 1.63
1−1/4 0.50 0.75 0.41 0.75 1.00 0.62 0.81 1.06 1.12 1.37 1.12 1.37 1.50 1.81
1−1/2 0.56 0.81 0.44 0.81 1.06 0.69 0.88 1.13 1.25 1.50 1.25 1.50 1.75 2.06
2 0.62 0.87 0.50 0.88 1.19 0.75 1.00 1.31 1.50 1.81 1.50 1.81 2.00 2.31
2−1/2 0.69 0.94 0.56 1.00 1.31 0.81 1.12 1.43 1.62 1.93 1.62 1.93 2.25 2.62
3 0.75 1.00 0.62 1.12 1.43 0.91 1.25 1.56 1.50 1.81 2.12 2.43 2.62 3.00
4 0.94 1.19 0.69 1.25 1.56 1.06 1.50 1.81 1.75 2.06 2.12 2.43 3.00 3.44
5 0.94 1.19 0.75 1.38 1.69 1.12 1.75 2.03 2.00 2.31 2.88 3.19 3.62 4.12
6 1.00 1.25 0.81 1.44 1.75 1.19 1.88 2.19 2.19 2.50 3.25 3.62 4.25 4.75
8 1.12 1.37 0.94 1.62 1.93 1.38 2.19 2.50 2.50 2.81 3.62 4.06 5.00 5.56
10 1.19 1.44 1.00 1.88 2.19 −−−− 2.50 2.81 2.75 3.06 4.25 4.69 6.50 7.19
12 1.25 1.50 1.06 2.00 2.31 −−− 2.62 2.93 3.12 3.43 4.88 5.44 7.25 7.94
14 1.38 1.63 −−− 2.12 2.43 −−− 2.75 3.06 3.38 3.82 5.25 5.88 −−− −−−
16 1.44 1.69 −−− 2.25 2.56 −−− 3.00 3.31 3.50 3.94 5.75 6.44 −−− −−−
18 1.56 1.81 −−− 2.38 2.69 −−− 3.25 3.56 4.00 4.50 6.38 7.07 −−− −−−
20 1.69 1.94 −−− 2.50 2.88 −−− 3.50 3.88 4.25 4.75 7.00 7.69 −−− −−−
24 1.88 2.13 −−− 2.75 3.19 −−− 4.00 4.44 5.50 6.12 8.00 8.81 −−− −−−
30 2.12 −−− −−− 3.00 −−− −−− −−− −−− −−− −−− −−− −−− −−− −−−
36 2.38 −−− −−− 3.38 −−− −−− −−− −−− −−− −−− −−− −−− −−− −−−
42 2.62 −−− −−− 3.69 −−− −−− −−− −−− −−− −−− −−− −−− −−− −−−
48 2.75 −−− −−− 4.00 −−− −−− −−− −−− −−− −−− −−− −−− −−− −−−
1. These dimensions apply to steel valves for nominal pipe sizes 1 through 24.
Chapter 11. Pipe Data
255
Cast Steel Flange Standard for PN 16
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015202532
666.577
9095
105115140
1616181818
60657585
100
44444
M12M12M12M12M16
1414141418
40506580
100
7.5888.59.5
150165185200220
1820182020
110125145160180
44488
M16M16M16M16M16
1818181818
125150175200250
1011121214
250285315340405
2222242426
210240270295355
888
1212
M16M20M20M20M24
1822222226
300350400500600
1516182123
460520580715840
2830323640
410470525650770
1216162020
M24M24M27M30M33
2626303336
700800900
10001200
2426272932
9101025112512551485
4242444652
840950
105011701390
2424282832
M33M36M36M39M45
3639394248
14001600180020002200
3436394143
16851930213023452555
5864687074
15901820202022302440
3640444852
M45M52M52M56M56
4856566262
All dimensions in mm.
Chapter 11. Pipe Data
256
Cast Steel Flange Standard for PN 25
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015202532
666.577
9095
105115140
1616181818
60657585
100
44444
M12M12M12M12M16
1414141418
40506580
100
7.588.59
10
150165185200235
1820222424
110125145160190
44888
M16M16M16M16M20
1818181822
125150175200250
1112121214
270300330360425
2628283032
220250280310370
88
121212
M24M24M24M24M27
2626262630
300350400500600
1516182123
485555620730845
3438404446
430490550660770
1616162020
M27M30M33M33M36
3033363639
700800900
10001200
2426272932
9601085118513201530
5054586270
875990
109012101420
2424282832
M39M45M45M52M52
4248485656
1400160018002000
34374043
1755197521952425
76849096
1640186020702300
36404448
M56M56M64M64
62627070
All dimensions in mm.
Chapter 11. Pipe Data
257
Cast Steel Flange Standard for PN 40
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
DIameter1015202532
666.577
9095
105115140
1616181818
60657585
100
44444
M12M12M12M12M16
1414141418
40506580
100
7.588.59
10
150165185200235
1820222424
110125145160190
44888
M16M16M16M16M20
1818181822
125150175200250
1112131416
270300350375450
2628323438
220250295320385
88
121212
M24M24M27M27M30
2626303033
300350400450500
1719212121
515580660685755
4246505052
450510585610670
1616162020
M30M33M36M36M39
3336393942
600700800900
1000
2427303336
890995
114012501360
6064727680
795900
103011401250
2024242828
M45M45M52M52M52
4848565656
120014001600
424754
157517952025
8898
108
146016801900
323640
M56M56M64
626270
All dimensions in mm.
Chapter 11. Pipe Data
258
Cast Steel Flange Standard for PN 63
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015253240
1010101210
100105140155170
2020242428
7075
100110125
44444
M12M12M16M20M20
1414182222
506580
100125
1010111213
180205215250295
2626283034
135160170200240
48888
M20M20M20M24M27
2222222630
150175200250300
1415161921
345375415470530
3640424652
280310345400460
812121216
M30M30M33M33M33
3333363636
350400500600700
2326313540
600670800930
1045
5660687684
525585705820935
1616202024
M36M39M45M52M52
3942485656
800900
10001200
45505564
1165128514151665
9298
108126
1050117012901530
24282832
M56M56M64
M72X6
62627078
All dimensions in mm.
Chapter 11. Pipe Data
259
Cast Steel Flange Standard for PN 100
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015253240
1010101210
100105140155170
2020242428
7075
100110125
44444
M12M12M16M20M20
1414182222
506580
100125
1011121416
195220230265315
3034364040
145170180210250
48888
M24M24M24M27M30
2626263033
150175200250300
1820212529
355385430505585
4448526068
290320360430500
1212121216
M30M30M33M36M39
3333363942
350400500600700
3236445159
655715870990
1145
747894
104120
560620760875
1020
1616202024
M45M45M52M56M64
4848566270
All dimensions in mm.
Cast Steel Flange Standard for PN 160
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015254050
1010101010
100105140170195
2020242830
7075
100125145
44444
M12M12M16M20M24
1414182226
6580
100125150
1112141618
220230265315355
3436404450
170180210250290
8888
12
M24M24M27M30M30
2626303333
175200250300
19213136
390430515585
54606878
320360430500
12121216
M33M33M39M39
36364242
All dimensions in mm.
Chapter 11. Pipe Data
260
Cast Steel Flange Standard for PN 250
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
DIameter1015254050
1010111313
125130150185200
2426283438
8590
105135150
44448
M16M16M20M24M24
1818222626
6580
100125150
1416192225
230255300340390
4246546068
180200235275320
888
1212
M24M27M30M30M33
2630333336
175200250300
29323847
430485585690
7482
100120
355400490590
12121616
M36M39M45M48
39424852
All dimensions in mm.
Cast Steel Flange Standard for PN 320
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015254050
1111111415
125130160195210
2426343842
8590
115145160
44448
M16M16M20M24M24
1818222626
6580
100125150
1819242732
255275335380425
5155657584
200220265310350
888
1212
M27M27M33M33M36
3030363639
175200250
353849
485525640
95103125
400440540
121616
M39M39M48
424252
All dimensions in mm.
Chapter 11. Pipe Data
261
Cast Steel Flange Standard for PN 400
DNPIPE
THICK−NESS
FLANGE BOLTING
OutsideDiameter
ThicknessBolt
CircleDiameter
Numberof
BoltsThread
BoltHole
Diameter1015254050
1111121518
125145180220235
2830384852
85100130165180
44448
M16M20M24M27M27
1822263030
6580
100125150
2225303641
290305370415475
64688092
105
225240295340390
888
1212
M30M30M36M36M39
3333393942
175200
4753
545585
120130
450490
1216
M45M45
4848
All dimensions in mm.
Chapter 11. Pipe Data
262
263
Chapter 12
Conversions and Equivalents
Length EquivalentsNote: Use
Multiplier atConvergenceof Row and
Column
Meters Inches Feet Millimeters Miles Kilometers
Meters 1 39.37 3.2808 1000 0.0006214 0.001
Inches 0.0254 1 0.0833 25.4 0.00001578 0.0000254
Feet 0.3048 12 1 304.8 0.0001894 0.0003048
Millimeters 0.001 0.03937 0.0032808 1 0.0000006214
0.000001
Miles 1609.35 63,360 5,280 1,609,350 1 1.60935
Kilometers 1,000 39,370 3280.83 1,000,000 0.62137 11 meter = 100 centimeters = 1000 millimeters = 0.001 kilometers = 1,000,000 micrometersTo convert metric units, merely adjust the decimal point1 millimeter = 1000 microns = 0.03937 inches = 39.37 mils.
Whole Inch−Millimeter Equivalents
In.0 1 2 3 4 5 6 7 8 9
mm
0102030
0.0254.0508.0762.0
25.4279.4533.4787.4
50.8304.8558.8812.8
76.2330.2584.2838.2
101.6355.6609.6863.6
127.0381.0635.0889.0
152.4406.4660.4914.4
177.8431.8685.8939.8
203.2457.2711.2965.2
228.6482.6736.6990.6
40506070
1016.01270.01524.01778.0
1041.41295.41549.41803.4
1066.81320.81574.81828.8
1092.21346.21600.21854.2
1117.61371.61625.61879.6
1143.01397.01651.01905.0
1168.41422.41676.41930.4
1193.81447.81701.81955.8
1219.21473.21727.21981.2
1244.61498.61752.62006.6
8090100
2032.02286.02540.0
2057.42311.42565.4
2082.82336.82590.8
2108.22362.22616.2
2133.62387.62641.6
2159.02413.02667.0
2184.42438.42692.4
2209.82463.82717.8
2235.22489.22743.2
2260.62514.62768.6
Note: All values in this table are exact, based on the relation 1 in = 25.4 mm. By manipulation of the decimal point anydecimal value or multiple of an inch may be converted to its exact equivalent in millimeters.
Chapter 12. Conversions and Equivalents
264
Fractional Inches To Millimeters(1 Inch = 25.4 Millimeters)
In.0 1/16 1/8 3/16 1/4 5/16 3/8 7/16
mm
0123
0.025.450.876.2
1.627.052.477.8
3.228.654.079.4
4.830.255.681.0
6.431.857.282.6
7.933.358.784.1
9.534.960.385.7
11.136.561.987.3
4567
101.6127.0152.4177.8
103.2128.6154.0179.4
104.8130.2155.6181.0
106.4131.8157.2182.6
108.0133.4158.8184.2
109.5134.9160.3185.7
111.1136.5161.9187.3
112.7138.1163.5188.9
89
10
203.2228.6254.0
204.8230.2255.6
206.4231.8257.2
208.0233.4258.8
209.6235.0260.4
211.1236.5261.9
212.7238.1263.5
214.3239.7265.1
Fractional Inches To Millimeters (continued)(1 Inch = 25.4 Millimeters)
In.1/2 9/16 5/8 11/16 3/4 13/16 7/8 15/16
mm
0123
12.738.163.588.9
14.339.765.190.5
15.941.366.792.1
17.542.968.393.7
19.144.569.995.3
20.646.071.496.8
22.247.673.098.4
23.849.274.6100.0
4567
114.3139.7165.1190.5
115.9141.3166.7192.1
117.5142.9168.3193.7
119.1144.5169.9195.3
120.7146.1171.5196.9
122.2147.6173.0198.4
123.8149.2174.6200.0
125.4150.8176.2201.6
89
10
215.9241.3266.7
217.5242.9268.3
219.1244.5269.9
220.7246.1271.5
222.3247.7273.1
223.8249.2274.6
225.4250.8276.2
227.0252.4277.8
Additional Fractional/Decimal Inch—Millimeter Equivalents INCHES
MILLI−METERS
INCHESMILLI−
METERS
INCHESMILLI−
METERSFrac−tions
Decimals Frac−tions
Decimals Frac−tions
Decimals
1/64
.00394
.00787
.01
.01181
.015625
.1
.2
.254
.3
.3969
13/64
7/32
.2
.203125
.21
.21875
.22
5.085.15945.3345.55625.588
29/64
15/32
.44
.45
.453125
.46
.46875
11.17611.43011.509411.68411.9062
.01575
.01969
.02
.02362
.02756
.4
.5
.508
.6
.7
15/64
1/4
.23
.234375
.23622
.24
.25
5.8425.95316.06.0966.35
31/64
.47
.47244
.48
.484375
.49
11.93812.012.19212.303112.446
1/32.03.03125.0315.03543.03937
.762
.7938
.8
.91.0
17/64.26.265625.27.27559.28
6.6046.74696.8587.07.112
1/2
33/64
.50
.51
.51181
.515625
.52
12.712.95413.013.096913.208
(continued)
Chapter 12. Conversions and Equivalents
265
Additional Fractional/Decimal Inch—Millimeter Equivalents (continued)INCHES
MILLI−METERS
INCHESMILLI−
METERS
INCHESMILLI−
METERSFrac−tions
MILLI−METERSDecimals
Frac−tions
MILLI−METERSDecimals
Frac−tions
MILLI−METERSDecimals
3/64
1/16
.04
.046875
.05
.06
.0625
1.0161.19061.271.5241.5875
9/32
19/64
.28125
.29
.296875
.30
.31
7.14387.3667.54067.627.874
17/32
35/64
.53
.53125
.54
.546875
.55
13.46213.493813.71613.890613.970
5/64.07.078125.07874.08.09
1.7781.98442.02.0322.286
5/16
21/64
.3125
.31496
.32
.328125
.33
7.93758.08.1288.33448.382
9/16
37/64
.55118
.56
.5625
.57
.578125
14.014.22414.287514.47814.6844
3/32
7/64
.09375
.1
.109375
.11
.11811
2.38122.542.77812.7943.0
11/32
23/64
.34
.34375
.35
.35433
.359375
8.6368.73128.899.09.1281
19/32
.58
.59
.59055
.59375
.60
14.73214.98615.015.081215.24
1/8
9/64
.12
.125
.13
.14
.140625
3.0483.1753.3023.5563.5719
3/8
.36
.37
.375
.38
.39
9.1449.3989.5259.6529.906
39/64
5/8
.609375
.61
.62
.625
.62992
15.478115.49415.74815.87516.0
5/32.15.15625.15748.16.17
3.8103.96884.04.0644.318
25/64
13/32
.390625
.39370
.40
.40625
.41
9.921910.010.1610.318810.414
41/64
21/32
.63
.64
.640625
.65
.65625
16.00216.25616.271916.51016.6688
11/64
3/16
.171875
.18
.1875
.19
.19685
4.36564.5724.76254.8265.0
27/64
7/16
.42
.421875
.43
.43307
.4375
10.66810.715610.92211.011.1125
43/64
.66
.66929
.67
.671875
.68
16.76417.017.01817.065617.272
11/16
45/64
.6875
.69
.70
.703125
.70866
17.462517.52617.7817.859418.0
51/64
13/16
.796875
.80
.81
.8125
.82
20.240620.32020.57420.637520.828
29/32
59/64
.90551
.90625
.91
.92
.921875
23.023.018823.11423.36823.4156
23/32
47/64
.71
.71875
.72
.73
.734375
18.03418.256218.28818.54218.6531
53/64
27/32
.82677
.828125
.83
.84
.84375
21.021.034421.08221.33621.4312
15/16.93.9375.94.94488.95
23.62223.812523.87624.024.130
3/4
49/64
.74
.74803
.75
.76
.765625
18.79619.019.05019.30419.4469
55/64.85.859375.86.86614.87
21.59021.828121.84422.022.098
61/64
31/32
.953125
.96
.96875
.97
.98
24.209424.38424.606224.63824.892
25/32
.77
.78
.78125
.78740
.79
19.55819.81219.843820.020.066
7/8
57/64
.875
.88
.89
.890625
.90
22.22522.35222.60622.621922.860
63/64
1
.98425
.984375
.991.00000
25.025.003125.14625.4000
Round off decimal points to provide no more than the desired degree of accuracy.
Chapter 12. Conversions and Equivalents
266
Area EquivalentsNote: Use
Multiplier atConvergence of
Row and Column
SquareMeters
SquareInches
SquareFeet
SquareMiles
SquareKilometers
Square Meters 1 1549.99 10.7639 3.861 x 10−7 1 x 10−6
Square Inches 0.0006452 1 6.944 x 10−3 2.491 x 10−10 6.452 x 10−10
Square Feet 0.0929 144 1 3.587x 10−8 9.29 x 10−8
Square Miles 2,589,999 – – – 27,878,400 1 2.59
Square Kilometers 1,000,000 − − − 10,763,867 0.3861 11 square meter = 10,000 square centimeters.1 square millimeter = 0.01 square centimeter = 0.00155 square inches.
Volume EquivalentsNote: Use
Multiplier atConvergence of
Row andColumn
CubicDeci-
meters(Liters)
CubicInches
CubicFeet
U.S.Quart
U.S.Gallon
ImperialGallon
U.S.Barrel
(Petro−leum)
Cubic Decimeters(Liters)
1 61.0234 0.03531 1.05668 0.264178 0.220083 0.00629
Cubic Inches 0.01639 1 5.787 x 10−4 0.01732 0.004329 0.003606 0.000103
Cubic Feet 28.317 1728 1 29.9221 7.48055 6.22888 0.1781
U.S. Quart 0.94636 57.75 0.03342 1 0.25 0.2082 0.00595
U.S. Gallon 3.78543 231 0.13368 4 1 0.833 0.02381
Imperial Gallon 4.54374 277.274 0.16054 4.80128 1.20032 1 0.02877
U.S. Barrel(Petroleum)
158.98 9702 5.6146 168 42 34.973 1
1 cubic meter = 1,000,000 cubic centimeters.1 liter = 1000 milliliters = 1000 cubic centimeters.
Volume Rate EquivalentsNote: Use
Multiplier atConvergenceof Row and
Column
LitersPer Minute
CubicMeters
Per Hour
Cubic FeetPer Hour
LitersPer
Hour
U.S. GallonPer
Minute.
U.S.Barrel
Per Day
LitersPer Minute
1 0.06 2.1189 60 0.264178 9.057
Cubic MetersPer Hour
16.667 1 35.314 1000 4.403 151
Cubic FeetPer Hour
0.4719 0.028317 1 28.317 0.1247 4.2746
LitersPer Hour
0.016667 0.001 0.035314 1 0.004403 0.151
U.S. GallonPer Minute
3.785 0.2273 8.0208 227.3 1 34.28
U.S. BarrelPer Day
0.1104 0.006624 0.23394 6.624 0.02917 1
Chapter 12. Conversions and Equivalents
267
Mass Conversion—Pounds to Kilograms(1 pound = 0.4536 kilogram)
Pounds0 1 2 3 4 5 6 7 8 9
Kilograms
0102030
0.004.549.07
13.61
0.454.999.53
14.06
0.915.449.98
14.52
1.365.90
10.4314.97
1.816.35
10.8915.42
2.276.80
11.3415.88
2.727.26
11.7916.33
3.187.71
12.2516.78
3.638.16
12.7017.24
4.088.62
13.1517.69
40506070
18.1422.6827.2231.75
18.6023.1327.6732.21
19.0523.5928.1232.66
19.5024.0428.5833.11
19.9624.4929.0333.57
20.4124.9529.4834.02
20.8725.4029.9434.47
21.3225.8630.3934.93
21.7726.3130.8435.38
22.2326.7631.3035.83
8090
36.2940.82
36.7441.28
37.2041.73
37.6542.18
38.1042.64
38.5643.09
39.0143.55
39.4644.00
39.9244.45
40.3744.91
Ch
apter 12. C
on
version
s and
Eq
uivalen
ts
268 Pressure EquivalentsNote: Use Multiplier at
Convergence of Row and ColumnKg. PerSq. Cm.
Lb. PerSq. In.
Atm. Bar In. ofHg.
Kilopascals In. ofWater
Ft. ofwater
Kg. Per Sq. Cm. 1 14.22 0.9678 0.98067 28.96 98.067 394.05 32.84
Lb. Per Sq. In. 0.07031 1 0.06804 0.06895 2.036 6.895 27.7 2.309
Atm. 1.0332 14.696 1 1.01325 29.92 101.325 407.14 33.93
Bar 1.01972 14.5038 0.98692 1 29.53 100 402.156 33.513
In. of Hg. 0.03453 0.4912 0.03342 0.033864 1 3.3864 13.61 11.134
Kilopascals 0.0101972 0.145038 0.0098696 0.01 0.2953 1 4.02156 0.33513
In. of Water 0.002538 0.0361 0.002456 0.00249 0.07349 0.249 1 0.0833
Ft. of Water 0.03045 0.4332 0.02947 0.029839 0.8819 2.9839 12 11 ounce/sq. inch = 0.0625 lbs./sq. inch
Pressure Conversion—Pounds per Square Inch to Bar*
Pounds PerSquare Inch
0 1 2 3 4 5 6 7 8 9
Bar
0102030
0.0000000.6894761.3789512.068427
0.0689480.7584231.4478992.137375
0.1378950.8273711.5168472.206322
0.2068430.8963181.5857942.275270
0.2757900.9652661.6547422.344217
0.3447381.0342141.7236892.413165
0.4136851.1031611.7926372.482113
0.4826331.1721091.8615842.551060
0.5515811.2410561.9305322.620008
0.6205281.3100041.9994802.688955
40506070
2.7579033.4473794.1368544.826330
2.8268503.5163264.2058024.895278
2.8957983.5852744.2747504.964225
2.9647463.6542214.3436975.033173
3.0336933.7231694.4126455.102120
3.1026413.7921174.4815925.171068
3.1715883.8610644.5505405.240016
3.2405363.9300124.6194875.308963
3.3094843.9989594.6884355.377911
3.3784314.0679074.7573835.446858
8090
100
5.5158066.2052826.894757
5.5847536.2742296.963705
5.6537016.3431777.032652
5.7226496.4121247.101600
5.7915966.4810727.170548
5.8605446.5500197.239495
5.9294916.6189677.308443
5.9984396.6879157.377390
6.0673866.7568627.446338
6.1363346.8258107.515285
Note: To convert to kilopascals, move decimal point two positions to right; to convert to Megapascals, move decimal point one position to left. For example, 30 psi = 2.068427 bar = 206.8427 kPa =0.2068427 MPa.Note: Round off decimal points to provide no more than the desired degree of accuracy.
Chapter 12. Conversions and Equivalents
269
Temperature Conversion FormulasTo Convert From To Substitute in Formula
Degrees Celsius Degrees Fahrenheit (�C x 9/5) + 32
Degrees Celsius Kelvin (�C + 273.16)
Degrees Fahrenheit Degrees Celsius (�F−32) x 5/9
Degrees Fahrenheit Degrees Rankin (�F + 459.69)
Temperature Conversions
�C
Temp. in�C or �F
to beConverted
�F �C
Temp. in�C or �F
to beConverted
�F �C
Temp. in�C or �F
to beConverted
�F
−273.16−267.78−262.22−256.67−251.11
−245.56−240.00−234.44−228.89−223.33
−217.78−212.22−206.67−201.11−195.56
−190.00−184.44−178.89−173.33−169.53
−168.89−167.78−162.22−156.67−151.11
−145.56−140.00−134.44−128.89−123.33
−117.78−112.22−106.67−101.11−95.56
−459.69−450−440−430−420
−410−400−390−380−370
−360−350−340−330−320
−310−300−290−280
−273.16
−272−270−260−250−240
−230−220−210−200−190
−180−170−160−150−140
−459.69
−457.6−454.0−436.0−418.0−400.0
−382.0−364.0−346.0−328.0−310.0
−292.0−274.0−256.0−238.0−220.0
−90.00−84.44−78.89−73.33−70.56
−67.78−65.00−62.22−59.45−56.67
−53.89−51.11−48.34−45.56−42.78
−40.00−38.89−37.78−36.67−35.56
−34.44−33.33−32.22−31.11−30.00
−28.89−27.78−26.67−25.56−24.44
−23.33−22.22−21.11−20.00−18.89
−130−120−110−100−95
−90−85−80−75−70
−65−60−55−50−45
−40−38−36−34−32
−30−28−26−24−22
−20−18−16−14−12
−10−8−6−4−2
−202.0−184.0−166.0−148.0−139.0
−130.0−121.0−112.0−103.0−94.0
−85.0−76.0−67.0−58.0−49.0
−40.0−36.4−32.8−29.2−25.6
−22.0−18.4−14.8−11.2−7.6
−4.0−0.43.26.8
10.4
14.017.621.224.828.4
−17.8−16.7−15.6−14.4−13.3
−12.2−11.1−10.0
−8.89−7.78
−6.67−5.56−4.44−3.33−2.22
−1.1101.112.223.33
4.445.566.677.788.89
10.011.112.213.314.4
15.616.717.818.920.0
02468
1012141618
2022242628
3032343638
4042444648
5052545658
6062646668
32.035.639.242.846.4
50.053.657.260.864.4
68.071.675.278.882.4
86.089.693.296.8
100.4
104.0107.6111.2114.8118.4
122.0125.6129.2132.8136.4
140.0143.6147.2150.8154.4
(continued)
Chapter 12. Conversions and Equivalents
270
Temperature Conversions (continued)
�C �F
Temp. in�C or �F
to beConverted
�C�F
Temp. in�C or �F
to beConverted
�C�F
Temp. in�C or �F
to beConverted
21.122.223.324.425.6
26.727.828.930.031.1
32.233.334.435.636.7
37.843.348.954.460.0
65.671.176.782.287.8
93.398.9
104.4110.0115.6
121.1126.7132.2137.8143.3
148.9154.4160.0165.6171.1
176.7182.2187.8193.3198.9
7072747678
8082848688
9092949698
100110120130140
150160170180190
200210220230240
250260270280290
300310320330340
350360370380390
158.0161.6165.2168.8172.4
176.0179.6183.2186.8190.4
194.0197.6201.2204.8208.4
212.0230.0248.0266.0284.0
302.0320.0338.0356.0374.0
392.0410.0428.0446.0464.0
482.0500.0518.0536.0554.0
572.0590.0608.0626.0644.0
662.0680.0698.0716.0734.0
204.4210.0215.6221.1226.7
232.2237.8243.3248.9254.4
260.0265.6271.1276.7282.2
287.8293.3298.9304.4310.0
315.6321.1326.7332.2337.8
343.3348.9354.4360.0365.6
371.1376.7382.2387.8393.3
398.9404.4410.0415.6421.1
426.7432.2437.8443.3448.9
400410420430440
450460470480490
500510520530540
550560570580590
600610620630640
650660670680690
700710720730740
750760770780790
800810820830840
752.0770.0788.0806.0824.0
842.0860.0878.0896.0914.0
932.0950.0968.0986.01004.0
1022.01040.01058.01076.01094.0
1112.01130.01148.01166.01184.0
1202.01220.01238.01256.01274.0
1292.01310.01328.01346.01364.0
1382.01400.01418.01436.01454.0
1472.01490.01508.01526.01544.0
454.4460.0465.6471.1476.7
482.2487.8493.3498.9504.4
510.0515.6521.1526.7532.2
537.8543.3548.9554.4560.0
565.6571.1576.7582.2587.8
593.3598.9604.4610.0615.6
621.1626.7632.2637.8643.3
648.9654.4660.0665.6671.1
676.7682.2687.8693.3698.9
850860870880890
900910920930940
950960970980990
10001010102010301040
10501060107010801090
11001110112011301140
11501160117011801190
12001210122012301240
12501260127012801290
1562.01580.01598.01616.01634.0
1652.01670.01688.01706.01724.0
1742.01760.01778.01796.01814.0
1832.01850.01868.01886.01904.0
1922.01940.01958.01976.01994.0
2012.02030.02048.02066.02084.0
2102.02120.02138.02156.02174.0
2192.02210.02228.02246.02264.0
2282.02300.02318.02336.02354.0
(continued)
Chapter 12. Conversions and Equivalents
271
Temperature Conversions (continued)
�C �F
Temp. in�C or �F
to beConverted
�C�F
Temp. in�C or �F
to beConverted
�C�F
Temp. in�C or �F
to beConverted
704.4710.0715.6721.1726.7
732.2737.8743.3748.9754.4
13001310132013301340
13501360137013801390
2372.02390.02408.02426.02444.0
2462.02480.02498.02516.02534.0
760.0765.6771.1776.7782.2
787.0793.3798.9804.4810.0
14001410142014301440
14501460147014801490
2552.02570.02588.02606.02624.0
2642.02660.02678.02696.02714.0
815.6 1500 2732.0
A.P.I. and Baumé Gravity Tables and Weight Factors
A.P.I.Gravity
BauméGravity
SpecificGravity
Lb/U.S. Gal
U.S.Gal/Lb
A.P.I.Gravity
BauméGravity
SpecificGravity
Lb/U.S. Gal
U.S.Gal/Lb
012345
6789
10
1112131415
1617181920
2122232425
2627282930
10.2479.2238.1987.1736.1485.124
4.0993.0742.0491.025
10.00
10.9911.9812.9713.9614.95
15.9416.9317.9218.9019.89
20.8821.8722.8623.8524.84
25.8326.8227.8128.8029.79
1.07601.06791.05991.05201.04431.0366
1.02911.02171.01431.00711.0000
0.99300.98610.97920.97250.9659
0.95930.95290.94650.94020.9340
0.92790.92180.91590.91000.9042
0.89840.89270.88710.88160.8762
8.9628.8958.8288.7628.6988.634
8.5718.5098.4488.3888.328
8.2708.2128.1558.0998.044
7.9897.9357.8827.8307.778
7.7277.6767.6277.5787.529
7.4817.4347.3877.3417.296
0.11160.11240.11330.11410.11500.1158
0.11670.11750.11840.11920.1201
0.12090.12180.12260.12350.1243
0.12520.12600.12690.12770.1286
0.12940.13030.13110.13200.1328
0.13370.13450.13540.13620.1371
3132333435
3637383940
4142434445
4647484950
5152535455
5657585960
30.7831.7732.7633.7534.73
35.7236.7137.7038.6939.68
40.6741.6642.6543.6444.63
45.6250.6150.6050.5950.58
50.5751.5552.5453.5354.52
55.5156.5057.4958.4859.47
0.87080.86540.86020.85500.8498
0.84480.83980.83480.82990.8251
0.82030.81550.81090.80630.8017
0.79720.79270.78830.78390.7796
0.77530.77110.76690.76280.7587
0.75470.75070.74670.74280.7389
7.2517.2067.1637.1197.076
7.0346.9936.9516.9106.870
6.8306.7906.7526.7136.675
6.6376.6006.5636.5266.490
6.4556.4206.3856.3506.316
6.2836.2496.2166.1846.151
0.13790.13880.13960.14050.1413
0.14220.14300.14390.14470.1456
0.14640.14730.14810.14900.1498
0.15070.15150.15240.15320.1541
0.15490.15580.15660.15750.1583
0.15920.16000.16090.16170.1626
(continued)
Chapter 12. Conversions and Equivalents
272
A.P.I. and Baumé Gravity Tables and Weight Factors (continued)A.P.I.
GravityU.S.
Gal/LbLb/
U.S. GalSpecificGravity
BauméGravity
A.P.I.Gravity
U.S.Gal/Lb
Lb/U.S. Gal
SpecificGravity
BauméGravity
6162636465
6667686970
7172737475
7677787980
60.4661.4562.4463.4364.42
65.4166.4067.3968.3769.36
70.3571.3472.3373.3274.31
75.3076.2977.2878.2779.26
0.73510.73130.72750.72380.7201
0.71650.71280.70930.70570.7022
0.69880.69530.69190.68860.6852
0.68190.67870.67540.67220.6690
6.1196.0876.0566.0255.994
5.9645.9345.9045.8745.845
5.8175.7885.7595.7315.703
5.6765.6495.6225.5955.568
0.16340.16430.16510.16600.1668
0.16770.16850.16940.17020.1711
0.17190.17280.17360.17450.1753
0.17620.17700.17790.17870.1796
8182838485
8687888990
9192939495
96979899100
80.2581.2482.2383.2284.20
85.1986.1887.1788.1689.15
90.1491.1392.1293.1194.10
95.0996.0897.0798.0699.05
0.66590.66280.65970.65660.6536
0.65060.64760.64460.64170.6388
0.63600.63310.63030.62750.6247
0.62200.61930.61660.61390.6112
5.5425.5165.4915.4655.440
5.4155.3905.3655.3415.316
5.2935.2695.2465.2225.199
5.1765.1545.1315.1095.086
0.18040.18130.18210.18300.1838
0.18470.18550.18640.18720.1881
0.18890.18980.19060.19150.1924
0.19320.19400.19490.19570.1966
The relation of Degrees Baumé or A.P.I. to Specific Gravity is expressed by thefollowing formulas:
For liquids lighter than water:
Degrees Baumé = 140G
– 130, G = 140130 � Degrees Baume
Degrees A.P.I. = 141.5G
– 131.5, G = 141.5131.5 � Degrees A.P.I.
For liquids heavier than water:
Degrees Baumé = 145 – 145G
G �145
145−Degrees Baume
G = Specific Gravity = ratio of the weight of a given volume of oil at 60� Fahren-heit to the weight of the same volume of water at 60� Fahrenheit.
The above tables are based on the weight of 1 gallon (U.S.) of oil with a volumeof 231 cubic inches at 60� Fahrenheit in air at 760 mm pressure and 50% humid-ity. Assumed weight of 1 gallon of water at 60� Fahrenheit in air is 8.32828pounds.
To determine the resulting gravity by mixing oils of different gravities:
D �
md1 � nd2m � n
D = Density or Specific Gravity of mixturem = Proportion of oil of d1 densityn = Proportion of oil of d2 densityd1 = Specific Gravity of m oild2 = Specific Gravity of n oil
Chapter 12. Conversions and Equivalents
273
Extracted from Technical Paper No. 410, Flow of Fluids, with permission of Crane Co.
Chapter 12. Conversions and Equivalents
274
Chapter 12. Conversions and Equivalents
275
Other Useful ConversionsTo Convert From To Multiply By
Cu Ft (Methane) B.T.U. 1000 (approx.)
Cu Ft of Water Lbs of Water 62.4
Degrees Radians 0.01745
Gals Lbs of Water 8.336
Grams Ounces 0.0352
Horsepower (mech.) Ft Lbs per Min 33,000
Horsepower (elec.) Watts 746
Kg Lbs 2.205
Kg per Cu Meter Lbs per Cu Ft 0.06243
Kilowatts Horsepower 1.341
Lbs Kg 0.4536
Lbs of Air(14.7 psia and 60�F) Cu Ft of Air 13.1
Lbs per Cu Ft Kg per Cu Meter 16.0184
Lbs per Hr (Gas) Std Cu Ft per Hr 13.1/Specific Gravity
Lbs per Hr (Water) Gals per Min 0.002
Lbs per Sec (Gas) Std Cu Ft per Hr47.193/Specific
Gravity
Radians Degrees 57.3
Scfh Air Scfh Propane 0.81
Scfh Air Scfh Butane 0.71
Scfh Air Scfh 0.6 Natural Gas 1.29
Scfh Cu Meters per Hr 0.028317
Metric Prefixes and SymbolsMultiplication Factor Prefix Symbol
1 000 000 000 000 000 000 = 1018 1 000 000 000 000 000 = 1015
1 000 000 000 000 = 1012
1 000 000 000 = 109
1 000 000 = 106
1 000 = 103
100 = 102
10 = 101
exapetateragiga
megakilo
hectodeka
EPTGMkhda
0.1 = 10−1
0.01 = 10−2
0.001 = 10−3
0.000 001 = 10−6
0.000 000 001 = 10−9
0.000 000 000 001 = 10−12
0.000 000 000 000 001 = 10−15
0.000 000 000 000 000 001 = 10−18
decicentimilli
micronanopico
femtoatto
dcmµnpfa
Chapter 12. Conversions and Equivalents
276
277
Subject Index
Bold page numbers indicate tables.Italic page numbers indicate figures.
A.P.I. and Baumé Gravity Tables andWeight Factors, 271
Accessory, 2
Actuator, 2, 27, 61, 129, 172assembly, 2diaphragm, 8, 10, 61, 172direct, 10double−acting, 16electro−hydraulic, 64force calculations, 133lever, 13manual, 64, 65piston, 9, 30, 63piston type, 11rack and pinion, 64, 64reverse, 12sizing, 129spring, 6spring−and−diaphragm, 27stem, 6stem extension, 8stem force, 8
Actuator−positioner design, 27
Allowable sizing pressure drop, 115
Ambient temperature corrosion, 96
American Petroleum Institute, 175
American Pipe Flange Dimensions,251, 252
diameter of bolt circles, 251flange diameter, 253
flange thickness for flange fittings,254
number of stud bolts and diameter,252
American Society of Mechanical Engi-neers, 175
Angle−style valve body, 42
ANSI, 18
API, 18
Approval Agencies, 179
Approvals, 179Asia/Pacific, 185European, 185North American, 179product, 179
Area Equivalents, 266
ASME, 18
ASTM, 18
ASTM material designations, 78
Automatic control system, 18
Backlash, 2, 27
Ball, 13full, 13V−notch, 15
Balanced−plug cage−style valve body,43
Bar stock valve body, 43
Bellows seal bonnet, 8, 9, 51, 51
Bench set, 16, 174, 174
Subject Index
278
Bode diagram, 18, 19
Bolt tightening, 169
Bonnet, 9, 49, 50bellows seal, 8, 9, 51, 51extension, 8, 10, 50, 51valve body, 49
Bonnet assembly, 9
Booster, 70
Bottom flange, 9
Bushing, 9
Butterfly control valve, 45
Butterfly valve body, 45
Cage, 9, 10, 143characterized, 10equal percentage, 10linear, 10noise abatement, 143quick opening, 10
Cage-style trim, 11
Calculations for pipe other thanschedule 40, 236
Calibration, 18, 68curve, 18, 19cycle, 18hysteresis, 19
Cam-operated limit switches, 71
Canadian Standards Association, 178
Capacity, 16
Cavitation, 136, 141
CENELEC approvals, 178
Characteristic, 3equal percentage, 3, 32frequency response, 20inherent, 4, 31inherent valve, 4installed, 4linear, 4, 32quick opening, 5, 32
Characterization, 31, 58
Characterized cages, 58equal percentage, 58linear, 58quick opening, 58
Characterized valve plugs, 58
Clearance flow, 16
Closed loop, 2
Closure member, 10
Comparison of protection techniques,183
Control range, 2
Control valve, 1, 23accessories, 67assembly, 2, 7butterfly, 45high capacity, 147high-temperature, 148low-flow, 148, 149maintenance, 169nuclear service, 151packing, 52performance, 23rotary-shaft, 14, 15selection, 75standards, 175V-notch ball, 46
Controller, 2, 20
Conversions, 263
CSA enclosure ratings, 182
Customized characteristic, 150
Cylinder, 10
Cyrogenic service valve, 149
Dead band, 2, 25, 26, 29
Dead time, 3
Desuperheater, 156fixed geometry nozzle design, 156installations, 156self-contained, 160self-contained design, 159steam assisted, 160steam atomized design, 160variable geometry nozzle, 159
Desuperheating, 155
Diagnostics, 170
Diaphragm, 10case, 10plate, 10
Diaphragm actuator, 8, 10, 61, 62direct-acting, 62reverse-acting, 62
Direct actuator, 10
Subject Index
279
Disk, 3conventional, 15dynamically designed, 15eccentric, 15
Double-acting, 64electro-hydraulic, 63piston, 63
Double-acting actuator, 16
Double-ported valve, 11
Double-ported valve body, 44
Dynamic gain, 28
Dynamic unbalance, 16
Eccentric-disk control valve body, 46
Eccentric-plug valve body, 47
Effective area, 16
Elastomer information, 101
Electric relay, 69
Electro-hydraulic actuator, 64
Electro-pneumatic positioner, 72, 74
Electro-pneumatic transducer, 72, 74
End connections, 48bolted gasketed flanges, 48screwed pipe threads, 47welding, 48
Engineering data, 191
Enthalpy, 20
Entropy, 20
Equal-percentage flow characteristic,3, 16, 109
Equation constants, 111
Equivalents, 263
European approvals, 185
European Committee for Electrotech-nical Standardization, 178
European Committee for Standardiza-tion, 176
Extension bonnet, 8, 10, 51
Face-to-face dimensions, 86, 89
Fail-closed, 16
Fail-open, 16
Fail-safe, 16
Fail-safe system, 72
FCI, 20
Feedback signal, 20
Feedforward, 162
Final control element, 3
Fixed geometry nozzle design, 159
Fixed-gain positioner, 30
Flangeless valve, 15
Flow characteristic, 59, 108equal-percentage, 16, 59inherent, 17installed, 17, 33, 33linear, 59modified parabolic, 17quick-opening, 59selection, 108
Flow coefficient, 16rated, 18relative, 18
Flow control processes, 110
Flow of Air Through Schedule 40Steel Pipe, 232
Flow of Water Through Schedule 40Steel Pipe, 228
Fluid compatibility, 103
Fluid Controls Institute, 176
Fractional Inches To Millimeters, 264
Frequency response characteristic, 20
Friction, 3, 27, 178in-service, 178packing, 27piston actuator, 27trending, 178
Gaindynamic, 28inherent valve, 4installed, 33installed valve, 4loop, 5, 34loop process, 34static, 28
Gain limit specification, 34
Geometry-assisted wafer, 161, 161
Globe valve, 10
Subject Index
280
Handwheel, 69
Hardness, 20
Hazardous location classification, 179,199
High-capacity valve body, 44
High-performance butterfly controlvalve, 45
High-pressure valve body, 43
High-recovery valve, 16
High-temperature control valves, 148
Hunting, 20
Hydrocarbonsphysical constants, 200
Hysteresis, 4
I/P, 4
IEC enclosure rating, 188
Ingress protection (IP) codes, 188
Inherent characteristic, 4, 31
Inherent diaphragm pressure range,17
Inherent flow characteristic, 4, 17, 150
Inherent flow characteristics curves,59
Inherent valve characteristic, 109
Inherent valve gain, 4
Inline diffuser, 142
Installation, 167, 168
Installed diaphragm pressure range,17
Installed flow characteristic, 4, 17, 33
Installed valve gain, 4
Instrument air leakage, 183
Instrument air quality 184
Instrument pressure, 20
Instrument Society of America, 177,178
International Electrotechnical Commis-sion, 178, 179
International Standards Organization,179
Intrinsically safe apparatus, 183
ISA, 20
Large flow valve body, 148
Length Equivalents, 263
Limit switches, 68cam-operated, 71
Linear characteristic, 4
Linear flow characteristic, 59, 107
Linearity, 4
Liquid critical pressure ratio factor, 116
Liquid level systems, 109
Loading pressure, 20
Loop, 2closed, 2open, 5
Loop gain, 5, 34
Low-flow control valve, 148
Low-recovery valve, 17
Lower valve body, 10
Maintenance, 167, 169control valve, 169predictive, 170preventive, 169reactive, 169
Manifold, 163
Manual actuator, 63, 64
Manufacturers Standardization, 178
Mass Conversion-Pounds to Kilo-grams, 267
Maximum flow rate, 115
Maximum rotation, 134
Metric Prefixes and Symbols, 275
Modified parabolic flow characteristic,17
NACE, 20, 179
National Electrical Manufacturer’s As-sociation, 179
National Fire Protection Association,179
NEMA enclosure rating, 181
Subject Index
281
Noise abatement trim, 141, 143
Noise control, 139aerodynamic, 139
Noise prediction, 139aerodynamic, 139hydrodynamic, 140
Non-destructive test procedure, 134
North American Approvals, 179
Nuclear servicecontrol valve, 151
Offset valve, 10
Open loop, 5
OSHA, 20
Other Useful Conversions, 275
Packing, 5, 27, 52, 130, 173control valve, 52friction, 27, 131, 132laminated and filament graphite, 52material, 12, 52PTFE V-ring, 52rotary valves, 146selection, 144sliding-stem valves, 145
Packing box assembly, 10
Performance test loop, 25
Physical Constants of Hydrocarbons,200
Pipe data, 237Carbon and Alloy Steel − Stainless
Steel, 238
Pipe Engagement, 237
Piping geometry factor, 113
Piston actuator, 9, 11, 30, 61, 63double-acting, 63
Piston actuator friction, 27
Plug, 12eccentric, 15
Pneumatic lock-up systems, 72
Port, 12
Port-guided single-port valve body, 44
Positioner, 5, 27, 67analog I/P, 67
cams, 35diaphragm actuator, 69digital, 67electro-pneumatic, 72fixed-gain, 30microprocessor-based, 28piston actuator, 70pneumatic, 67two-stage, 28
Predictive maintenance, 170
Pressureinstrument, 20loading, 20supply, 21
Pressure Equivalents, 268
Pressure Conversion, 268
Pressure drop ratio factor, 121
Preventive maintenance, 169
Process, 5
Process dead band, 3
Process gain, 5
Process optimization, 31
Process variability, 5, 23, 24
Properties of Saturated Steam, 212
Properties of Superheated Steam, 219
Properties of Water, 211
Protection techniques, 188
Push-down-to-close, 17
Push-down-to-open, 17
Quick-opening flow characteristic, 5,58, 108
Rack and pinion actuator, 64, 65
Range, 20
Rangeability, 18
Rated flow coefficient, 18
Rated travel, 18
Reactive maintenance, 169
Recommended seat load, 130, 130
Refrigerant 717 (Ammonia)Properties of Liquid and Saturated
Vapor, 206
Regulator, supply pressure, 71, 72
Subject Index
282
Relative flow coefficient, 18
Relay, 5
Repeatability, 19, 20
Resolution, 5
Response time, 5
Restricted-capacity trim, 61
Retaining ring, 12
Reverse actuator, 12
Reverse flow, 15
Reverse-acting diaphragm actuator,62
Rod end bearing, 15
Rotary actuator sizing, 133
Rotary-shaft control valve, 14, 15
Rubber boot, 12
Saturated Steamproperties, 212
Seal, 15ring, 15
Seal bushing, 12
Seat, 12, 130, 173leakage, 18load, 12, 130ring, 12, 173ring puller, 174
Seat leakage classifications, 93
Sensitivity, 21
Sensor, 5
Service Temperature Limitations forElastomers, 94
Set point, 6
Shaft, 15
Shaft wind-up, 30
Signal, 21
Signal amplitude sequencing, 19, 21
Single-port valve body, 41, 42
Sizing, 6, 132coefficients, 125rotary actuator, 132valve, 6
Sliding seal, 16
Sliding-stem packing, 57
Solenoid, 72
Solenoid valve, 69
Span, 21
Specific Heat Ratio, 202
Spring adjustor, 13
Spring rate, 18
Spring seat, 13
Spring-and-diaphragm actuator, 27,172
Standard flow, 16
Static gain, 28
Static unbalance, 13
Steam conditioning valve, 162
Stem connector, 13
Stem packing, 172
Stem unbalance, 18
Stroking time, 31
Sulfide stress cracking, 151
Superheated steam, 155properties, 219
Supply pressure, 21, 69regulator, 69, 71
T63 (Tee−63), 6, 29
Temperature code, 180, 181
Temperature Conversions, 269
Three-way valve body, 11, 45
Thrust-to-friction ratio, 30
Time constant, 6
Torque equations, 133breakout torque, 133dynamic torque, 133
Torque factors, 134
Transducer, 70, 71electro-pneumatic, 70, 71
Transmitter, 6
Travel, 6
Travel indicator, 6
Travel deviation, 171
Trim, 6, 11, 13, 58cage-style, 11
Subject Index
283
restricted-capacity, 61
Trim material temperature limits, 94
Turbine bypass, 155, 165valve, 165
Turbine bypass system, 165, 165components, 165
Two-stage positioner, 28
Unbalance areas, 128
Upper valve body, 13
V-notch ball valve body, 46
Valve, 159steam conditioning, 155turbine bypass, 165
Valve body, 41, 43, 75, 167angle, 9angle-style, 11, 42assembly, 13balanced-plug cage-style, 43bar stock, 43bonnet, 49butterfly, 45capacity, 2double-ported, 11, 44, 44eccentric-disk, 47, 47eccentric-plug, 47flangeless, 15flow arrow, 168globe, 10high capacity, cage-guided, 44high-capacity, 44high-recovery, 17inspection, 168lower, 10materials, 74offset, 10port-guided single-port, 44single-port, 41single-ported, 42storage, 167three-way, 11, 45, 45upper, 13
Valve diagnostics, 68
Valve materials, 191recommended standard specifica-
tions, 191
Valve plug, 13, 58characterized, 58
Valve plug guiding, 59cage guiding, 59stem guiding, 60top guiding, 60top-and-bottom guiding, 60top-and-port guiding, 60
Valve response time, 29
Valve sizing, 6, 36, 110, 118compressible fluids, 118for liquids, 110
Valve stem, 13
Valve type, 31
Valve-body, V-notch ball, 46
Variable geometry nozzle, 151
Velocity of liquids in pipe, 226
Vena contracta, 18
Vent diffuser, 142
Viscosity conversion, 274
Volume and Weight Flow Rates, 273
Volume booster, 6, 70
Volume Equivalents, 266
Volume Rate Equivalents, 266
Wear & galling resistance, 92
Welding end connections, 48
Whole Inch-Millimeter Equivalents,263
Yoke, 13
Zero error, 21
top related