forged steel valves bolted bonnet - rencor · pdf file · 2013-06-26forged steel...

FORGED STEEL VALVESBOLTED BONNET MAINTENANCE MANUALGate, Globe, Parallel Slide and Check Valves, 21/2”–24”(65-600mm)

VEL–FBBM–99Maintenance

Manuals

2

GENERAL INFORMATION PAGE

I INTRODUCTION ........................................................................................................................5

1.1 General Introduction ..............................................................................................................................51.2 Essential Features of Velan Valves........................................................................................................6

II RECEIVING & PREPARATION FOR INSTALLATION ..........................................................................7

2.1 Receiving Inspection ..............................................................................................................................72.2 Quality Control Documentation ............................................................................................................72.3 Storage ....................................................................................................................................................72.4 Handling and Preparation ......................................................................................................................72.5 Special Instructions for Gate Valves ....................................................................................................72.6 Special Instructions for Globe Valves ..................................................................................................82.7 Special Instructions for Check Valves ..................................................................................................82.8 Special Instructions for Tilting Disc Check Valves ..............................................................................92.9 Recheck for Bolt Tightness ....................................................................................................................9

III WARNINGS ..........................................................................................................................10

IV GENERAL MAINTENANCE ........................................................................................................11

4.1 Trouble Shooting Chart........................................................................................................................114.2 Operation ..............................................................................................................................................12

4.2.1 General ......................................................................................................................................124.2.2 Smoothness of Operation ........................................................................................................12

4.3 Recommended Lubrication..................................................................................................................124.4 General Assembly Information ..........................................................................................................124.5 Body/Bonnet & Body/Cover Torquing Procedure ..............................................................................13

4.5.1 General ......................................................................................................................................134.5.2 Torque Procedure ......................................................................................................................134.5.3 Application of Torque................................................................................................................13

V INFORMATION PERTINENT TO GATE, GLOBE, STOP CHECK

AND PARALLEL SLIDE VALVES ................................................................................................15

5.1 Packing ..................................................................................................................................................155.1.1 Number of Packing Rings Required ........................................................................................155.1.2 Packing Ring Removal On Line ................................................................................................155.1.3 Removal With Blowout..............................................................................................................165.1.4 Repacking With Graphite Packing Rings..................................................................................17

for Valves Without a Leak-Off Connection5.1.5 Repacking With Graphite Packing Rings..................................................................................19

for Valves With a Leak-Off Connection5.1.6 Packing Torques ........................................................................................................................205.1.7 Live-Loading Packings ..............................................................................................................20

5.2 Detailed Maintenance ..........................................................................................................................215.2.1 Packing Chamber Leakage ........................................................................................................215.2.2 Body/Bonnet (Gasket) Leakage ................................................................................................21

5.2.2.1 General ......................................................................................................................215.2.2.2 Seal Welding & Removal of the Body/Bonnet Joint ..............................................21

5.2.3 Seat Leakage ..............................................................................................................................23

TABLE OF CONTENTS

5.2.3.1 General ......................................................................................................................235.2.3.2 Wedge & Disc Repairs - Gate & Parallel Slide Valves............................................235.2.3.3 Seat Repairs ..............................................................................................................24

5.2.3.3.1 Gate & Parallel Slide Valves ..................................................................245.2.3.3.2 Globe, Needle, Stop & Piston Check Valves ........................................25

5.2.3.4 Fitting of Repaired Parts ..........................................................................................275.2.3.4.1 Gate Valves..............................................................................................275.2.3.4.2 Parallel Slide Valves................................................................................285.2.3.4.3 Globe, Stop Check and Piston Check Valves ........................................29

5.2.3.5 Seat Tightness - Closing Torques............................................................................315.2.4 Backseat Repairs ........................................................................................................................31

5.3 Torque Values - Actuator, Yoke/Bonnet Bolting ................................................................................32

GATE VALVE PAGE

VI GATE VALVE ........................................................................................................................33

6.1 Gate Valve Assembly Drawing ............................................................................................................336.2 Exploded View ......................................................................................................................................346.3 Gasket Replacement ............................................................................................................................356.4 Total Disassembly of Gate Valves ......................................................................................................36

6.4.1 General ......................................................................................................................................366.4.2 Disassembly of Body/Bonnet and Wedge/Stem ....................................................................366.4.3 Disassembly of Top Works ......................................................................................................37

6.5 Assembly ..............................................................................................................................................386.5.1 Top Works Assembly ................................................................................................................386.5.2 Body/Bonnet and Wedge/Stem Assembly

(Valve Internal & Mid-Section)..................................................................................................38

GLOBE VALVE

VII GLOBE VALVE ......................................................................................................................39

7.1 Globe & Piston Check Valve Assembly Drawings ............................................................................397.2 Gasket Replacement ............................................................................................................................407.3 Total Disassembly of Globe Valves ....................................................................................................41

7.3.1 General ......................................................................................................................................417.3.2 Disassembly of Body/Bonnet and Disc/Stem Union ..............................................................417.3.3 Disassembly of Top Works ......................................................................................................43

7.4 Total Disassembly of Stop Check Valves............................................................................................437.5 Total Disassembly of Piston Check Valve ..........................................................................................447.6 Assembly ..............................................................................................................................................44

7.6.1 Top Works Assembly ................................................................................................................447.6.2 Body/Bonnet and Disc/Stem Assembly (Valve Internal & Mid-Section) ..............................45

PARALLEL SLIDE

VIII PARALLEL SLIDE ..................................................................................................................46

8.1 Parallel Slide Valve Assembly Drawing..............................................................................................468.2 Gasket Replacement ............................................................................................................................47

8.2.1 Alternate Gasket Replacement Procedure ..............................................................................49

TABLE OF CONTENTS

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8.3 Total Disassembly of Parallel Slide Valves ........................................................................................508.3.1 General ......................................................................................................................................508.3.2 Disassembly of Body/Bonnet and Discs/Stem ........................................................................508.3.3 Disassembly of Top Works ......................................................................................................52

8.4 Assembly ..............................................................................................................................................538.4.1 Top Works Assembly ................................................................................................................538.4.2 Body/Bonnet and Discs/Stem Assembly..................................................................................53

SWING CHECK AND TILTING DISC VALVES PAGE

IX SWING CHECK & TILTING DISC VALVES ..................................................................................55

9.1 Check Valve Assembly Drawings ........................................................................................................559.2 Gasket Replacement ............................................................................................................................569.3 Total Disassembly ................................................................................................................................56

9.3.1 Body/Bonnet Disassembly ........................................................................................................569.3.2 Disc Assembly............................................................................................................................56

9.3.2.1 Swing Check..............................................................................................................569.3.2.2 Titling Disc ................................................................................................................59

9.4 Detailed Maintenance ..........................................................................................................................599.4.1 Body/Bonnet (Gasket) Leakage ................................................................................................59

9.4.1.1 General ......................................................................................................................599.4.1.2 Leakage of Body/Bonnet Joint ................................................................................59

9.4.2 Seat Leakage - Swing Check ....................................................................................................609.4.2.1 Swing Check Disc Repairs ........................................................................................609.4.2.2 Seat Repairs ..............................................................................................................60

9.4.3 Seat Leakage - Tilting Disc ........................................................................................................609.4.3.1 Tilting Disc Repairs - General.................................................................................. 609.4.3.2 Tilting Disc Seat Repairs - General ..........................................................................60

9.5 Assembly ..............................................................................................................................................619.5.1 Disc Assembly Fit-Up ................................................................................................................61

9.5.1.1 Swing Check Disc Unit..............................................................................................619.5.1.2 Tilting Disc Unit ........................................................................................................62

9.5.2 Bearing Blue or Developer Test................................................................................................629.5.2.1. Swing Check (Removal of disc is required) ............................................................629.5.2.2 Tilting Disc ................................................................................................................64

9.5.3 Paper or Light Test ....................................................................................................................649.5.3.1 Swing Check (Removal of disc is not required)......................................................649.5.3.2 Tilting Disc ................................................................................................................64

9.5.4 Internal and Mid-Section Assembly - Swing Check Valve ....................................................659.5.5 Body/Cover Assembly - Swing Check & Tilting Disc ..............................................................65

APPENDIX

IX APPENDIX ............................................................................................................................66

10.1 Procedure for Removing Manual Gear Actuator ..............................................................................6610.1.1 Style 1 ........................................................................................................................................6610.1.2 Style 2 ........................................................................................................................................67

10.2 Procedure for Removing Motor Actuators ........................................................................................6810.3 Procedure for Removing Motor Hydraulic or Pneumatic Actuators ................................................7010.4 Spare Parts ............................................................................................................................................70

Terms and Conditions of Sale ............................................................................................................................71

TABLE OF CONTENTS

4

5

INTRODUCTION I

This manual has been prepared by Velan

engineers, designers and maintenance

personnel to assist you in obtaining many

years of satisfactory service from your forged steel

valves. It will also assist you in restoring your valve

to the best working condition with a minimum of

time and expense.

Velan valves are designed and manufactured based

on many years of research and product develop-

ment and are constantly being improved. Before

beginning any major work, we recommend that you

read this booklet carefully at least once to under-

stand the valve's physical condition.

Please note that if you do not understand the

reason for the service problem, we suggest that you

get in touch with your local Velan representative or

call the Customer Service Manager for technical

assistance.

Before beginning any major work, we recommend

that you carefully check the nameplate on the valve

and record the figure number to identify the type

and size of valve. See the “Essential Features of

Velan Valves” form on the following page for an

explanation of Velan “Figure Numbers”.

1.1 GENERAL INTRODUCTION

6

I INTRODUCTION

Gate, Globe and Check ValvesType of Connection Size of connection Class Type Body/Bonnet Style Body Material Trim Material

A B C D E F G

— —

B 1 6 — 3 0 5 4 P — 0 2 T Se.g.: is a 10" (250mm) 1500 class carbon steel pressure seal gate valve with TS trim and buttweld ends.

TYPE OF CONNECTIONAA - Special C - Combination R - Flanged, ring joint W - Socket weldB - Butt weld F - Flanged, B16.5 U - Undrilled flanges X - Butt weld (intermediate class)

SIZE OF CONNECTION B

Customers have the choice of specifying valve size as part of the valve figure (“B”) using the numbers below, or indicating valve size separately.e.g.: B16-3054P-02TS (valve size is part of figure number) 10" (250mm) B-3054P-02TS (valve size is shown separately)08 - 2" (50mm) 12 - 4" (100mm) 16 - 10" (250mm) 21 - 18" (450mm) 26 - 26" (650mm) 34 - 34" (850mm) 99 - SPECIAL09 - 21⁄2" (65mm) 13 - 5" (125mm) 18 - 12" (300mm) 22 - 20" (500mm) 28 - 28" (700mm) 36 - 36" (900mm)10 - 3" (80mm) 14 - 6" (150mm) 19 - 14" (350mm) 23 - 22" (550mm) 30 - 30" (750mm) 42 - 42" (1050mm)11 - 31⁄2" (90mm) 15 - 8" (200mm) 20 - 16" (400mm) 24 - 24" (600mm) 32 - 32" (800mm) 48 - 48" (1200mm)

Valve Type Figure Number Designation for Live-loading and Leak-offAdd a one-digit suffix to the figure number:

Standard Gate or globe 0 - for live-loading, double packing and leak-offPacked 2 - for live-loading onlyValves 3 - for double packing and leak-off onlye.g.: B16-3054P-02TS-0 is a 10" (250mm) 1500 class carbon steel pressure seal gate valve with TS trim, live-loading, double packing and leak-off

ClassC0 – 150 1 – 300 2 – 600 3 – 1500 4 – 2500 5 – 4500 7 – 900 X – Special

TYPED01 - Flow control 05 - Conv. port gate 07 - Stop (globe) 09 - Needle 14 - Parallel Slide 34 - Tilting disc check03 - Piston check 06 - Full port gate 08 - Stop check 11 - Swing check 23 - Double disc gate 99 - Special

BODY/BONNET STYLEE4 – Vertical 6 – “Y” pattern (inclined) A – Special K – Pressure seal (cast)5 – Angle 8 – Elbow down B – Bolted bonnet (forged) P – Pressure seal (forged)

BODY MATERIALF01 - Special 09 - Chr. moly, F9, C12 15 - S/S, F347, CF8C 22 - Titanium GR. 5 28 - S/S F317, CG8M 36 - S/S F321H 42 - Titanium Gr. 1202 - A105, WCB 10 - S/S, F316H 16 - S/S, F304H 23 - Alloy 20 29 - S/S F317L, CG3M 37 - Incoloy 43 - Titanium03 - Chr. moly, F1, WC1 11 - S/S, F304, CF8 18 - S/S, F321, CF8C 24 - LF1 31 - LCC 38 - LC1 45 Nobium04 - Chr. moly, F5, C5 12 - S/S, F304L, CF3 19 - Monel M35 25 - LCB 32 - S/S F51 39 - LC2 44 - Ferralium 25505 - Chr. moly, F11, WC6 13 - S/S, F316, CF8M 20 - Inconel 625 26 - LF2 34 - F91 40 - Titanium Gr. 2/3 45 - S/S F5506 - Chr. moly, F22, WC9 14 - S/S, F316L, CF3M 21 - Hastelloy C 27 - LF3/LC3 35 - S/S F44, 254 SMO 41 - Titanium Gr. 7

TRIM MATERIALGCODE WEDGE / DISC SEATING SURFACE (1) SEAT SURFACE (1) STEM

AA Special Special Special

HC Hastelloy C Stellite 6 Hastelloy C

MS Stellite 6 Stellite 6 316

MY CF8M or 316 Stellite 6 316

TS Stellite 6 Stellite 6 410

XS Stellite 6 Stellite 6 Monel or Monel K

XX Monel Monel Monel

XY Monel Stellite 6 Monel

NA(2) 13% Chrome HRC 22 max. Stellite 6 13% CR HRC 22 max.

NB(2) Stellite or CF8M Stellite 6 SS 316

NC(2) Monel Stellite 6 Monel or Monel K

1. Base material is either the same as body or solid trim at manufacturer's option. 2. NACE service valves are supplied with bolting with maximum hardness of Rc. 22. Use NS for special NACE trim and specify details on order.

1.2 ESSENTIAL FEATURES OF VELAN VALVESThe figure numbers shown on this key are designed to cover essential features of Velan valves. Please use figure numbers to ensure prompt and accurate processing of your order. A detailed description must accompany any special orders.

NACE

H 2

SSE

RVIC

E(2)

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2.1 RECEIVING INSPECTION

All valves must be examined for signs of damagethat may have occurred during transportation.Any damage should by analyzed and a reportshould be issued. Serious damage should bereported to your local Velan representative or tothe Customer Service Manager so that a suitablearrangement for repairs can be made withoutdelay.

2.2 QUALITY CONTROL DOCUMENTATION

For valves purchased with Quality Control (QC)certification, check the package of documents tosee that the Quality Control certificates are com-plete as per the purchase order.

2.3 STORAGE

Valves should be stored in a suitably shelteredplace to prevent contamination by weather, dirt ordampness. The valve is shipped with end protec-tors on the inlet and outlet which should stay onthe valve until it is ready for installation.

NOTE: If actuators are involved, please referto the applicable manufacturer’s instructionsfor storage.

2.4 HANDLING AND PREPARATION

On large valves, a hoist is needed to assist installa-tion. A sling should be placed and positionedabout the valve so that the unit can be lifted verti-cally to its final destination. End protectors mustbe removed from all types of valves and connec-tions must be checked for cleanliness. Any visibleforeign matter must be removed from end connec-tions on weld-end valves. The weld-end prepara-tion must be cleaned properly with a suitable sol-vent such as acetone or alcohol. Do not use sol-vents containing chloride or fluoride. Ensure thatthe tapered area between the packing flange andstem is clear and free of foreign debris.

WARNING: During installation, welding andconstruction stage the valve midsectionaround the packing flange and stem should beprotected at all times, as foreign debris fromwelding, grinding etc. can fall in-between the

tapered area of the packing flange and stemthat can cause extensive damage to stem andassociated parts during valve cycling. In anycase, prior to cycling, the area between thestem, packing flange and gland bushing mustbe thoroughly cleaned off all foreign matter.

2.5 SPECIAL INSTRUCTIONS FOR GATE VALVES

The flow through gate valves can be from eitherend. There may be exceptions to this if bypasspiping is welded to the valve body or pressurerelief hole drilled in one side of valve gate. Checkyour piping layout drawing to ensure correct posi-tion and direction of flow. Gate valves should beinstalled and welded into the pipeline with thewedge or disc in the fully closed position. If thevalve is left open or partially open, it could distortand leak during operation. Also, leaving the valvein a fully closed position helps prevent weld spat-ter from falling directly onto the mating faces ofthe seats. The preferred orientation of a gatevalve is upright. The valve may be installed inother orientations, but any deviation from verticalis a compromise. Installation upside down is notrecommended because of possible dirt build-up inthe bonnet.

NOTE: Gate valves should not be used for throttling to control the flow, they are normally fully open or fully closed. If left in apartially open position, could result in severedamage to body seats, wedge, stem and guiderails.

RECEIVING & PREPARATION FOR INSTALLATION II

2.6 SPECIAL INSTRUCTIONSFOR GLOBE VALVES

Globe valves are usually installed with the inletbelow the valve seat. This must be checked carefullyto prevent incorrect installation. If throttling serviceis particularly severe, Velan recommends that thevalve be installed so that the flow enters over the topof the seat and goes down through it. This maintainsthe valve in a more stable condition. The amount ofwear is minimized and there is less external noise.Valve operation also becomes easier because lesstorque is required to close the valve.

Globe type valves should be installed and weldedwith the disc in a fully closed position to preventdamage to the valve during installation. Leaving thedisc in a fully closed position also prevents weldspatter from falling directly onto the mating faces ofthe seat and disc.

The preferred orientation of a globe valve is upright.The valve may be installed in other orientations, butany deviation from vertical is a compromise.Installation upside down is not recommendedbecause of possible dirt build-up in the bonnet.

PRECAUTION: Allow time for welding tocool before trying the valve for the firstime in the pipeline.

8

II RECEIVING & PREPARATION FOR INSTALLATION

2.7 SPECIAL INSTRUCTIONS FOR CHECK VALVES

Check valves must be installed with the inlet indirection of arrow. This must be checked carefullybefore installing the valve. Placing a check valvein the opposite direction to the flow will preventthe disc from swinging free and will therefore prevent normal operation of the valve.

NOTE: All check valves should be installed atleast ten pipe diameters away from upstreampumps, elbows, fittings or equipment. If closer installation is required, please consult a Velan Customer Service Manager. (See Fig. 2.7)

CAUTION: Velan piston check and stopcheck valves without springs should beinstalled with the bonnet up, and the angleof incline of the line should be no morethan 45° from horizontal. Also, the rollangle of the valve bonnet should be nomore than 45°from side to side.

Flow

45°max. 45°max.

45°max.

Figure 2.7 Check valve: Angle of incline and roll angle

9

RECEIVING & PREPARATION FOR INSTALLATION II

2.8. SPECIAL INSTRUCTIONS FOR TILTINGDISC CHECK VALVES

Tilting disc check valves can be installed horizontally or vertically according to the designspecifications and with the inlet in the direction

of the arrow. However, for vertical installation special disc machining is required and priorknowledge of design condition is necessary toensure correct applications. Placing a check valvein the opposite direction to the flow will preventthe disc from swinging free and will therefore prevent normal operation of the valve.

NOTE: All check valves should be installed atleast ten pipe diameters away from upstreampumps, elbows, fittings or equipment. If clos-er installation is required, please consult aVelan Customer Service Manager.

2.9 RECHECK FOR BOLT TIGHTNESS

To maintain the tightness of a factory-tested boltedbonnet or cover valve, it is essential that sufficientbolt tension exists at all times by having the propertorque on the nuts (See Table 4.5B for gasket boltsand Table 5.1A, B, & C for packing bolts.). The original torque might be lost due to vibration, relaxation of material caused by frequent temperature and pressure fluctuations, or by creepin high temperature application. It is recommendedthat the gasket joint be inspected for leakage periodically. The tightness of the joint bolt tensionshould be checked at approximately one year intervals, and if necessary retightened as follows:

1. Remove one nut at a time, lubricate stud andnut flats thoroughly with an approved antiseize compound and torque to recom-mended values shown in Table 4.5B.

2. Remove opposite nut and repeat procedureuntil all nuts have been retorqued.

3. Re-check bolt torque by going once aroundclockwise.

NOTE: If gasket must be replaced, followBody/Bonnet & Body/Cover TorquingProcedure, (Section 4.5).

10

III WARNING

FOR SAFETY REASONS,

it is important to take these precautions

Personnel making any adjustments on the valves should wearsafety equipment normally used to work with fluid in the linewhere the valve is installed.

Before removing the yoke nut under pressure, the valve should be in fully openposition in order to prevent injuries.

Before removing a valve from a line, line pressure must be relieved with no exception.

Velan valves can be equipped with a variety of manual gear, electric motor, hydraulic or pneumatic actuators. Generally, all pressure must be relieved fromboth sides of the valve before the actuator is removed.

A valve in the fully open position (backseated), should not be jammed-tight(over-torqued), to avoid thermal binding. It is our recommendation that thevalve be removed 1/4 turn of the handwheel from the fully open position. Thiswill also ensure that packing tightness is verifiable. In gear-operated valves,because of the backlash, it is difficult sometimes to ensure this position.

Valve standards, such as API and MSS, caution users that successful completion of a backseat test should not be construed as a

recommendation by the manufacturer that a valve may be repacked while it is under pressure. The backseat may be used as a means

of stopping or reducing packing leakage until the packing can be replaced under no pressure. Removal of packing

with the valve under pressure is at the owner’s risk.

☛

☛☛☛

☛

☛

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AREA GENERAL PROBLEMS PROCEDURE FOR REPAIR

• Packing compression • Packing chamber leakage• Gland bushing binding Gate, globe, parallel slide:

Section 5.2.1

• Packing worn • Repacking procedure• Stem, packing chamber Gate, globe, parallel slide:

damaged Section 5.2.1

• Gasket damaged • Replacement of gasket• Body or bonnet damaged Gate: Section 6.3

Globe: Section 7.3Parallel slide: Section 8.2Swing check: Section 9.3

• Tightness of bolting • Body-bonnet stud torquingGate, globe, parallel slide:Swing check: Section 4.5

• Lack of seating torque • Closing torqueGate, globe, parallel slide:Section 5.2.3.5

• Damaged seat faces • Seat repair (optional information availableupon request)

• Disc movement restricted • Disassembly and reassemblySwing check valves

• Packing compression Packing torqueGate, globe, parallel slide:Section 5.1.6

• Stem thread • Disassembly and reassembly• Stem nut thread Gate: Sections, 6.3, 6.4, 6.5

Globe: Sections, 7.2, 7.3, 7.4,7.5, 7.6Parallel slide: Sections, 8.2, 8.3, 8.4

GENERAL MAINTENANCE IV

PACKING

CHAMBER

LEAKAGE

BODY-BONNET

JOINT LEAKAGE

SEAT

LEAKAGE

OPERATIONAL

SMOOTHNESS

4.1 TROUBLE SHOOTING CHART

Table 4.1A Trouble Shooting Chart

12

IV GENERAL MAINTENANCE

4.2 OPERATION

4.2.1 General

All valves require examination before being putinto operation. Additionally, valves should beinspected regularly during operation and shouldreceive prompt attention when trouble arises. Asa general rule, valves should be subjected toscheduled maintenance.

4.2.2 Smoothness of Operation

Stem threads, gearing and other working components outside the fluid area should be lubricated frequently and at least once every sixmonths. Specific lubricants and frequency ofapplication are shown in the recommended lubrication table of Section 4.3. Valves that are notoperated frequently and which may remain openor closed for long periods of time should beworked (even if only partially) about once amonth.

IMPORTANT: Excessive handwheel effort canindicate the following:

a) Improperly lubricated or damaged valve stem.

b) Valve packing compression too tight(check torque table in Section 5.2.2).

c) Faulty or damaged valve parts.d) Foreign debris on threads and/or

packing area.

4.4 GENERAL ASSEMBLY INFORMATION

1. The most important fact to be considered isthe cleanliness of all parts. All rust and dirtshould be removed from all parts with a wirebrush or emery cloth. Oil and grease shouldbe removed with suitable solvents.

2. All threaded parts (cap screws, nuts, studs)must be well relubricated. The stem and stemnut threads should be clean of old greasebefore a new application of grease is applied.Recommended lubricants can be found inSection 4.3. Use correct lubricant for eachindividual part.

3. Repaired or replacement parts must bechecked to see that all repair procedures havebeen done and that all replacement parts (e.g.,packing rings, gaskets, etc.) have been checked for size so that they will fit into thevalve being serviced.

4. All orientation marks assigned during disassembly must be observed so that correctorientation is maintained. Where applicable,orientation marks should be made on partsnear the body serial number (e.g. wedge, disc, seat, etc.).

PART LUBRICATION APPLICATION FREQUENCY

Stem Exxon: Ronex MP, Castrol MP Directly to When threadsthreads or equivalent MP group (up to 6500F) threads appear dry

Ronex Extra duty 2 (above 6500F)

Yoke nut Exxon: Ronex MP, Castrol MP Inject through Concurrentlyor equivalent MP group (up to 6500F) grease fitting with stemRonex Extra duty 2 (above 6500F) at hub of yoke thread lubrication

All threaded parts - Anti-seize compound No. 425-A Thin coat on On valveexcept (Crane) or equivalent threads assembly onlystem and yoke nut - Nickel Anti-Seize to MIL-A-90TE

or MOLYKOTE P37

Recommended lubricant subject to change without notice.

Table 4.3 Recommended lubrication4.3 RECOMMENDED LUBRICATION

DIMENSION ‘A’ VALVE GASKET(INCHES) SIZE SIZE

.085-.090 to 16” (400 mm) 1/8” (3.17 mm)(2.16 mm - 2.28 mm) inclusive (nominal thickness)

.125 -.135 18” (450 mm) 3/16” (4.80 mm)(3.17 mm - 3.43 mm) and up (nominal thickness)

13

GENERAL MAINTENANCE IV

4.5 BODY/BONNET & BODY/COVERTORQUING PROCEDURE

4.5.1 General

The following recommendations in this section arefor ideal conditions. However, because of themany interacting tolerances, some latitude must begiven in the acceptance standards as follows.

1. The gasket may be fully compressed, i.e., zerogap between interfaces of the joint at a torqueeither less than or greater than the torquegiven in Table 4.5B. The following criteriashould be used. (Refer to Table 4.5Aand Fig. 4.5A).The bolt torque is satisfactory if:

a) The gasket is fully compressed at 90% of therecommended bolt torque, provided that100% torque value is finally applied.

b) The gasket is fully compressed at 100%torque.

c) The gap between the interfaces of the jointis no more than 0.003”(0.08 mm) after 125%torque has been applied and the bolts havebeen slackened individually and retorquedto 100% torque.

4.5.2 Torque Procedure

1. Clean all studs and nuts. Visually inspect allthreads to ensure removal of all foreign matter, rust, corrosion, burrs and previouslubricants.

2. Liberally cover the stud threads and the surface under the nut head with FELPRO typeC5A Hi-Temp Antiseize or nucleargrade (never SEEZ 5000) nickel base compound orapproved equivalent. Also, lubricate thefemale threads of the nuts and wipe off anyexcess lubricant that may adhere to any of the stainless steel parts with recommendedsolvents.

Recommended solvents for this work are:a) unused or redistilled acetoneb) alcohol

3. After tightening bolts by hand, follow the bolttightening sequence shown in Fig. 4.5B. Thissequence depends on the quantity of boltsused. The drawing illustrates the logical progression one should follow.

Table 4.5A Gasket recess dimensions

Note: Bonnet machining does not control gasket compression.Any repair to the body recess should maintain theabove dimensions.

4.5.3 Application of Torque

When applying the torque to the bolts, each boltshould be torqued in steps of approximately 20%of the final torque shown in Table 4.5B. It will befound that as the final torque is approached, therequired step will become much less than 20%.

After the final torque has been applied insequence. It is recommended that the bolts berechecked once around in a clockwise rotation.

On sizes of bolts larger than 1 1/8”, special torquemultipliers with ratios 1:7 or 1:6 should be usedfor torquing.

PRECAUTION:1. If tightening sequence is not followed, it

is possible that the gasket will not be compressed evenly, and may result in gasket leakage.

2. Over-torquing can cause deformation of the body or bonnet flange and can also cause joint leakage.

3. Do not use impacting devices to tighten up the bolting on the body/bonnet (cover). Use suitable mechanical devices for tightening.

4. Use hand torque wrenches. If torque wrenches are not suitable, use standardwrenches and the following guidelines will apply:

BOLT SIZE LENGTH OF WRENCHinches mm

3⁄8” 5” 1251⁄ 2” 6” 1509⁄16” 9” 2255⁄8” 12” 3003⁄4” 18” 4507⁄8” 24” 6001” 30” 7501 1⁄8” 36” 900

BOLTING MATERIAL

STUD SIZE B7M/L7M B7/B16 660 630 B8M CL.1 B8M CL.2

3⁄8 - 16UNC 15 (20) 20 (27) 20 (27) 20 (27) 15 (20) 20 (27)7⁄16 - 14UNC 25 (34) 30 (41) 25 (34) 35 (47) 25 (34) 25 (34)

1⁄2 - 13UNC 40 (54) 50 (68) 40 (54) 55 (75) 35 (47) 45 (61)9⁄16 - 12UNC 55 (75) 70 (95) 60 (81) 80 (108) 55 (75) 65 (88)

5⁄8 - 11UNC 75 (102) 100 (136) 80 (108) 100 (136) 70 (95) 85 (115)3⁄4 - 10UNC 135 (183) 170 (231) 150 (203) 200 (271) 125 (170) 150 (203)7⁄8 - 9UNC 200 (271) 270 (366) 250 (339) 300 (407) 200 (271) 200 (271)

1 - 8UNC 350 (475) 400 (542) 350 (475) 450 (610) 300 (407) 350 (475)

11⁄8 - 8UNC 500 (678) 600 (814) 500 (678) 650 (881) 450 (610) 450 (610)

11⁄4 - 8UNC 675 (915) 850 (1153) 700 (949) 950 (1288) 650 (881) 650 (881)

13⁄8 - 8UNC 900 (1220) 1200 (1627) 1000 (1356) 1300 (1763) 900 (1220) 900 (1200)

11⁄2 - 8UNC 1200 (1627) 1500 (2034) 1300 (1763) 1700 (2305) 1200 (1627) 1200 (1627)

15⁄8 - 8UNC 1600 (2170) 2000 (2712) 1700 (2305) 2200 (2983) 1500 (2034) –

13⁄4 - 8UNC 2000 (2712) 2500 (3390) 2100 (2848) 2800 (3797) 1900 (2576) –

17⁄8 - 8UNC 2500 (3390) 3100 (4204) 2600 (3526) 3500 (4746) 2300 (3119) –

2 - 8UNC 3000 (4068) 3800 (5153) 3200 (4339) 4200 (5695) 2800 (3797) –

21⁄8 - 8UNC 3600 (4882) 4500 (6102) 3800 (5153) 5000 (6780) 3400 (4610) –

21⁄4 - 8UNC 4400 (5966) 5400 (7322) 4600 (6238) 6100 (8272) 4100 (5560) –

21⁄2 - 8UNC 6000 (8136) 7500 (10170) 6400 (8678) 8500 (11526) 5700 (7729) –

14

IV GENERAL MAINTENANCE

Note:(1) Torque tolerance ±10%(2) Maximum temperature for S/S 630 is 650°F(3) For temperatures above 750°F (400°C) use 75% of the torque values shown.(4) Above torque values are with the bolts lubricated.

Table 4.5B Maximum Body/Bonnet Bolting Torque in ftlb (Nm).

GasketrecessDim. “A”

Figure 4.5A Gasket recess

6

3

2 8

7 1

5

4

Figure 4.5B Bolt tightening sequence

15

5.1 PACKING

5.1.1 Number of Packing Rings Required(see Figs 5.1A & B)

All Velan bolted bonnet gate, globe and parallelslide valves require seven packing rings (Fig. 5.1C). For valves equipped with a leak-offconnection, four packings are placed below thelantern ring and three above (Fig. 5.1D).

5.1.2 Packing Ring Removal on Line

Follow warning instructions in Section III beforereplacing packing rings on line.

1. Remove the packing flange nuts and, if fit withlive-loading, remove Belleville spring washers.

2. Lift packing flange and gland bushing as highas possible and secure.

3. For braided packing rings: Fig. 5.1C & D usespecial flexible removal tools (cork screw tip)Fig. 5.1E screw into the packing ring and pullout. For graphite ribbon packing Fig 5.1C & Dwith special “C”-saw tool Fig. 5.1F cut throughthe packings, apply downward pressure as youwork the tool in a back and forth motion. Blowout packing remains using instrument air orsuck out with a vaccum cleaner. Care must betaken not to scratch the stem or the walls ofthe packing chamber during the removal of thepacking rings.

4. If the valve is equipped with a leak-off pipe,there is a lantern ring after the third packingring. To remove the lantern ring, insert twohooks into the holes at the top of the lanternring or insert screw-in extracting wires wheretapped holes are provided. These tappedholes are 6-32 UNC for valves 21/2” (65 mm) to4” (100 mm), and 8-32 UNC for valves 6”(150 mm) and larger.

5. After the lantern ring is lifted, the last fourpacking rings can be removed using the procedure described in step 3.

NOTE: All of our designs can be equippedwith a blowout plug option. If this connectionis provided, the packing rings can be removedby applying gas or hydraulic pressure frombelow as shown in Fig. 5.1G See Section 5.1.3.

Figure 5.1A Graphite ribbon packing

Figure 5.1B Braided graphite packing ring

Figure 5.1C Seven packings shown

INFORMATION PERTINENT TO GATE, GLOBE, CHECK & V

PARALLEL SLIDE VALVES V

Lantern ring

BraidedpackingGraphite

ribbonpacking

Graphiteribbonpacking

Braidedpacking

Braidedpacking

Braidedpacking

Figure 5.1D Lantern ring configuration

16

03

17A

63

11

12

14

62

02

01 04

13A 13B

19A

19B

64

Blow out fitting

Figure 5.1G Removal with blowout

01 - Body02 - Bonnet03 - Yoke04 - Stem11 - Packing flange

12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)

14 - Lantern ring17A - HSH cap screw

19A- Gasket19B - Gasket

62 - Leak-off63 - Junk ring64 - Plug

5.1.3 Removal with Blowout (Fig. 5.1G)

1. Fully open the valve and tighten the stem firmly against the backseat.

2. Remove packing flange nut and live-loadingassemblies (if so equipped).

3. If valve is equipped with a leakoff pipe, blockoff connection.

4. Remove blowout plug and gasket. Attach the pressure source to the connection. The packing rings will be pushed out of thepacking chamber.

5. All packing rings can be removed simultaneously. This is a fast and efficientoperation.

NOTE: When applying gas pressure, this operation will happen quite quickly and it ispossible that trapped liquid will spray out.

Figure 5.1F ”C”-saw packing removal tool

Figure 5.1E Flexible packing removal toolcork screw tip

V INFORMATION PERTINENT TO GATE, GLOBE, CHECK &

PARALLEL SLIDE VALVES

PARTS DESCRIPTION

0304

15B 16B

11

12

13A 13B

02

19

36A

36C

15 16

01

Split packing adaptor

5.1.4 Repacking with Graphite Packing Rings forValves Without Leak-off Connection

1. Before repacking, check the stem and the packing chamber wall for damage. Packing Chamber: Scratches (damage) nodeeper than 0.010” (0.25 mm) per side can beremoved by polishing the surfaces with a buffing wheel (120 - 220 grit) or by machiningthe entire packing chamber surface. The sur-face finish should be 16 RMS or better.Stem: Scratches (damage) no deeper than0.010” (0.25 mm) per side can be removed bymachining the entire stem. Smooth portion upto the back seat. Surface finish should be 16RMS or better.

2. Insert the first packing ring (braided graphitetype, end ring) manually and place as deep intothe packing chamber as possible followed by 1graphite ribbon (intermediate packing ring).Refer to Fig. 5.1H.

3. Insert the split packing adaptor. Push the packing rings to the bottom of the chamber,making sure that the lap joint is not reversedduring the operation.

4. Place the gland bushing and packing flangeinto position (Fig. 5.1I) and compress the bottom packing by tightening the nuts to 130%of the torque value shown in Table 5.1A, B, or C.

NOTE: Ensure gland bolts/nuts are well lubricated with anti-seize compound.

5. Remove the nuts and split packing adaptors,insert the next graphite ribbon packing andrepeat the procedure above until all intermediate graphite ribbon packings havebeen torqued.

NOTE:

a) The split lap joints of each consecutive ringshould be staggered at approximately 120°so that the fourth ring installed has its lapback at the starting point (Fig. 5.1J).Subsequent packing rings should berepacked in the same manner until the special packing adaptors are no longerrequired and the standard gland bushing can be used.

b) In case valves are equipped with live-loading(Belleville spring washers) remove springwashers during precompression of packingrings, and reinstall at final torque

Figure 5.1H Insert braided end ring,followed by intermediate ring.

03

04

11

12

13A13B

15 16

02

19

01

Figure 5.1I Repacking with split packingadaptor

01 - Body 11 - Packing flange 15 - Stud 19 - Gasket02 - Bonnet 12 - Gland bushing 15B - Stud 36A - Guide bushing03 - Yoke 13A - Pkg ring (ends) 16 - Nut 36C - Guide ring04 - Stem 13B - Pkg rings (inter) 16B - Nut

01 - Body02 - Bonnet03 - Yoke

04 - Stem11 - Packing flange12 - Gland bushing

13A - Pkg ring (ends)

13B - Pkg rings (inter)15 - Stud16 - Nut19 - Gasket

17



PARTS DESCRIPTION

PARTS DESCRIPTION

0304

15B 16B

11

12

14

13A 13B

02

19

01

36A

36B

36C

62

18

6. Remove the nuts and split packing adaptor andinsert the last end ring (braided graphite type)lower gland bushing and check for bushingpositive engagement with packing chamber.

NOTE: As a rule of thumb 1⁄4” (6 mm) min.engagement of the gland bushing inside thepacking chamber is required. Lower the glandflange, relubricate the gland studs/nuts usinganti-seize compound and torque to valuesshown in Table 5.1A, B, or C and/or projectdrawing. Cycle the valve once, for approxi-mately the length of the packing chamber, first cycle, open then close and retighten to the appropriate torque value.

7. Repacking valves using “packing consolidationmethod”. When split packing adaptors is notavailable use the following procedure:

a) Insert one braided packing ring, followed byintermediate graphite packings and one lastbraided packing ring refer to Fig. 5.1C.

Lower the gland bushing and check for bushing positive engagement, see noteabove.

b) Torque down the gland bolts to torque valuesshown in Table 5.1A, B or C.

c) Cycle the valve approximately the length ofthe packing chamber. First open then closeand retighten the gland bolts to appropriatetorque values. Repeat this step approximatelyfour, five times until the packings becomefully consolidated (no more loss of torque)

NOTE: For motor operated valves (mov) usemov manual override handwheel to cycle open& close.

Figure 5.1K Leak-off connection



03

04

15B 16B

36A

36B

36C

13B

13A

11

12

02

19

01

16 15

Figure 5.1J Packings installed

01 - Body 12 - Gland bushing 16 - Nut02 - Bonnet 13A - Pkg ring (ends) 16B - Nut03 - Yoke 13B - Pkg rings (inter) 19 - Gasket04 - Stem 15 - Stud 36A - Guide bushing11 - Packing flange 15B - Stud 36B - Belleville washer

36C - Guide ring

01 - Body 05 - Wedge 14 - Lantern ring02 - Bonnet 11 - Packing flange 15B - Stud03 - Yoke 12 - Gland bushing 16B - Nut04 - Stem 13A - Pkg ring (ends) 19 - Gasket

13B - Pkg rings (inter) 36A - Guide bushing36B - Belleville washer36C - Guide ring62 - Leak-off pipe

PARTS DESCRIPTION PARTS DESCRIPTION

GLOBESIZE

150 300 600 900 1500

2.5” 20 20 20 20 20(65 mm) (27) (27) (27) (27) (27)

3” 24 24 24 24 24(80 mm) (33) (33) (33) (33) (33)

4” 32 32 32 32 32(100 mm) (43) (43) (43) (43) (43)

6” 50 50 50 95 85(150 mm) (68) (68) (68)) (129) (129)

8” 90 90 90 90 –(200 mm) (122) (122) (122) (122) –

10” 128 128 128 – –(250 mm) (174) (174) (174) – –

GATESIZE

150 300 600 900 1500

2.5” 20 20 20 20 20(65 mm) (27) (27) (27) (27) (27)

3” 24 24 24 24 24(80 mm) (33) (33) (33) (33) (33)

4” 32 32 32 32 32(100 mm) (43) (43) (43) (43) (43)

6” 44 44 44 60 60(150 mm) (60) (60) (60) (81) (81)

8” 68 68 68 105 105(200 mm) (92) (92) (92) (142) (142)

10” 80 80 80 128 128(250 mm) (108) (108) (108) (174) (174)

12” 85 85 85 128 155(300 mm) (115) (115) (115) (174) (210)

14” 128 128 128 165 150(350 mm) (174) (174) (174) (224) (203)

16” 122 122 142 160 185(400 mm) () (165) (193) (217) (251)

18” 82 82 160 150 –(450 mm) (111) (111) (217) (203) –

20” 104 104 182 – –(500 mm) (141) (141) (247) – –

24” – – 230 215 –(600 mm) – – (312) (292) –

19



Table 5.1A Packing Flange Stud/Nut Torques in ft⋅lb(N⋅m) for Graphite & Teflon Packings

5.1.5 Repacking with Graphite Rings for Valves with Leak-Off Connection (Fig. 5.1K)

1. Follow the same procedure as described insteps one through five of the previous section, Section 5.1.4, Repacking with GraphitePacking Rings for valves without leak- off connection.

2. Insert (1) braided graphite packing ring. Lower the lantern ring ensuring that it lines upwith the leak-off connection and repeat the procedure above.

3. Place (1) braided and (1) graphite ribbon packing ring above the lantern ring and precompress to 130% of torque value of Table 5.1A, B, & C.

NOTE: In case valves are equipped with live-loading (Belleville spring washers) removespring washers during precompression ofpacking rings, and reinstall at final torque.

4. Insert (1) last end ring braided graphite typelower gland bushing and check for positiveengagement. As a rule of thumb 1/4” (6 mm)engagement inside the packing chamber isrequired. Carefully align the gland bushingand packing flange. Relubricate glandbolts/nuts and torque down to values shownin Table 5.1A, B, & C and/or project drawing.Cycle the valve once, for approximately thelength of the packing chamber, first cycle,open then close and retighten to the appropriate torque values.

5. “Packing consolidation method” use the sameprocedure as described in Section 5.1.4, step 7except install four packing rings below thelantern ring and three above, refer to Fig. 5.1D

Table 5.1B Packing Flange Stud/Nut Torques inftlb (N⋅m) for Graphite & Teflon Packings

Table 5.1C Packing Flange Stud/Nut Torques in ft⋅lb(N⋅m) for Graphite & Teflon Packings

PARALLEL SLIDESIZE

150 300 600 900 1500

2” 20 20 20 – –(50 mm) (27) (27) (27) – –

3” 24 24 24 – –(80 mm) (33) (33) (33) – –

4” – – – – 32(100 mm) – – – – (43)

6” 18 18 18 – 60(150 mm) (24) (24) (24) – (81)

8” 68 68 68 – 105(200 mm) (92) (92) (92) – (142)

12” – – – 155 140(300 mm) – – – (210) (190)

20” 115 115 115 – –(500 mm) (156) (156) (156) – –

20



5.1.6 Packing Torques

Step 1: Clean all studs and nuts. Visually inspectall threads to ensure removal of all foreignmatter, rust, corrosion, burrs and previouslubricants.

Step 2: Liberally cover the stud threads and femalethreads of the nuts and nut flats with ananti-seize compound such as FELPRO typeC5A Hi-Temp, nickel base NEVER-SEEZE5000 or approved equivalent.

Step 3: Tighten the packing flange nuts a little at a time on each side, then torque in accordance with valve type, size, pressureclass and packing type as shown in Table 5.1A, B, or C.

NOTE: Values in Table 5.1A, B, or C are approximate for standard Velan valves.Whenever possible, refer to project engineering drawings for individual valvesand their required torques.

5.1.7 Live-Loading Packings

Installation of the packing rings follows theprocedures described in Sections 5.1.4 & 5.1.5(‘without’ and ‘with’ a leak-off connection,

Guidesleeve

Guidesleeve

Figure 5.1L Live loaded packing

respectively). The Belleville washers are not to beused while compressing individual packing into the packing chamber. However, if packingconsolidation method is used as described inSection 5.1.4 step 7, the belleville spring washers(live loading) must be in place prior to compressingthe packings.

IMPORTANT: 1/4” (6 mm) engagement of thegland bushing into the packing chamber isessential to ensure that the packing does notblowout. Velan’s standard live-loaded packingconfiguration for bolted bonnet valves is illustrated in Fig. 5.1L.

Assembly Procedure:1. On each gland stud, place spacer ring on the

packing flange, a guide sleeve, a stack ofBelleville washers (either single or double stackdepending on application), and a gland nut.

2. Tighten the gland nuts a little at a time on eachside up to the torque values indicated in Table 5.1A, B, & C.

NOTE: Make sure that the Belleville washersdo not slide laterally while tightening.

Single stacked Double stacked



5.2 DETAILED MAINTENANCE

5.2.1 Packing Chamber Leakage

If moisture or dripping occurs around the stem of the ID packing chamber, the following pointsmust be investigated before removing the packing:

1. Check if the packing flange is torqued downto the correct torque as shown in Table 5.1A,B, & C.

2. Check if the live-load arrangement is in correct order. Compare your live-loadingarrangement with Fig. 5.1L. If it is not correct,open the valve to the backseat position andtighten up on the back seat firmly.

3. Check if the gland bushing is binding againstthe packing chamber wall or stem. If so, fullyopen the valve and tighten the stem againstthe backseat firmly. Loosen the packingflange and realign the gland bushing. Tightenup the packing flange a little at a time on eachside, then torque down to the correct torqueas shown in Table 5.1A, B, & C.

4. After retightening, cycle the valve once forapproximately the length of the packingchamber and retighten nuts to original torquevalue (Table 5.1A, B, & C). If steps 1 through4 do not stop leakage, proceed with theremoval and replacement of the packingrings.

5.2.2 Body/Bonnet (Gasket) Leakage

5.2.2.1 General

To maintain the tightness of a factory-tested bolted bonnet or cover valve, it is essential toapply sufficient bolt tension at all times by havingthe proper torque on the nuts or cap screws. The

CAUTION: You must determine theeffectiveness of the backseat seal asyou dismantle the live-loadingarrangement. If leakage occurs dur-ing disassembly, line pressure mustbe shut off. Reassemble live-loadingarrangement in correct order, thentorque down to the correct torque asshown in Table 5.1A, B, & C.

21

original torque might be lost due to vibration,relaxation of material caused by frequent temperature and pressure fluctuations, or by creep in high temperature applications. Joint bolttension should be checked at approximately one-year intervals and, if necessary, retightenbolts in accordance with Section 2.9. Recheck forBolt Tightness

5.2.2.2 Seal Welding & Removal

1. Welding

Seal welding of the body/bonnet orbody/cover flange joints shall be performedwhen necessary to prevent leakage. This jointis not intended to carry the mechanical loadon the flange due to internal pressure, gasketcompression, thermal stresses or stem thrust.All these forces are taken up by the bolting.Bolting must be maintained under torquesshown in Table 4.5B, Section 4.5

2. Cutting of the Weld (Fig. 5.2A)In order to disassemble a bolted bonnet valvewith a seal welded body/bonnet joint (or abolted cover valve with a seal weldedbody/cover joint), all the nuts and studs mustbe removed first. Grind off the seal weldusing the body flange surface as a guide for the grinding to control the height of engagement.

Figure 5.2A Cutting of the weld

Figure 5.2D Completed weldingFigure 5.2B Welding process

3. Preparation for Welding

Before welding, the valve must be drained andthe flange lips cleaned with suitable solventsuch as Acetone, Alcohol or equal.

4. Qualifications

The welding procedure and welder should bequalified in accordance with the requirementsof Section IX of the ASME Boiler and PressureVessel Code.

5. Actual Welding Process (Fig. 5.2B)

Remove two nuts and studs in sequence asshown in Fig. 5.2C. This sequence is dependent upon the number of boltsemployed. The sketch is only an illustration

22

6

3

2 8

7 1

5

4

Figure 5.2C Bolt tightening sequence Figure 5.2E Examination of weld

as to one possible welding sequence. Afterremoving two studs, the seal weld should beapplied in the area exposed by the removal ofthe two studs. Complete the seal welding.Before proceeding to weld the next section, reinstall the two stud nuts and torque down inaccordance with torque values given in Table4.5B. Continue the same process for the remaining circumference of valve body/bonnetjoint.

NOTE: Tig weld process is recommended forthis purpose, when the weld is complete, itshould be examined by a liquid penetrantmethod according to the requirements of the recommended codes. Refer to Figs. 5.2D & 5.2E.





23

5.2.3 Seat Leakage

5.2.3.1 General

An indication of a valve leak is a pressure loss inthe high pressure line side after a valve has beenproperly closed. In the case of hot water or steamlines, note whether the downstream pipe remainshot beyond the usual length of time. This type ofleak may be the result of a distorted seat caused byimproper welding of the valve into the pipeline, orby stress relieving temperatures that may havebeen used during installation. Leaks can alsodevelop from failure to close the valve tightly,resulting in high-velocity flow through a smallopening. The hardfacing material (e.g., Stellite 6) iscorrosion and erosion-resistant, but grooves, pitmarks or other surface irregularities may still formon the mating surfaces. Valves which leak shouldbe repaired as quickly as possible to preventgreater damage caused by high velocity.

5.2.3.2 Wedge and Disc Repairs - Gate and Parallel Slide Valves

1. Disassemble valve as described in Section 6.4.2for gate valves and Section 8.3.2 for parallelslide valves, and inspect the wedge or disc forscratches or damage.

2. If seating faces are scratched, the wedge or discmust be lapped. Slight pitting, grooving orindentations no deeper than 0.005” (0.1 mm)can be removed by lapping. If defects cannotbe corrected by lapping, wedge or disc shouldbe ground or machined. Velan recommendsthat a maximum of 0.015” (0.4 mm) on eachside be removed from a 10-degree seatedwedge and 0.010” (0.25 mm) on each side for a7-degree seated wedge. For parallel slide discgate Velan recommends maximum removal of0.040” (1 mm) per disc.

NOTE: If more than 0.010” (0.25 mm) totalmust be removed from both discs and seats ofa paralled slide valve, then the retainer plate(45) must also be ground, milled or machinedto compensate for gap allowance, refer toSection 8.4.2 steps 2,3, 4 & 5 and Fig. 8.3E, Disc Type II & V, retaining plate (45),Disc Type IV, retaining ring (45) and Disc Type III Hex. head bolt (56A).

3. For the lapping, a flat plate, preferably castiron, should be used and an abrasive lapping compound mixed with olive oil should be evenly distributed over the plate as shown in Fig. 5.2F. Only light, even pressure should beapplied to the plate, lifting the wedge or disc asoften as possible to prevent accumulation ofparticles in one area and to allow for properdistribution of the lapping compound. The lapping plate should be turned slightly everyfew strokes to maintain a flat surface. The partshould be lapped until seating faces aresmooth. Velan recommends the use of CloverCompound (silicone carbide) grade “E”medium course and grade“C” fine grit compound for finishing or an approved equivalent.

Figure 5.2F Lapping of wedge or disc

4. Thoroughly clean off the lapping compoundwith a suitable cleaning fluid such as acetoneor alcohol. Do not use solvents containingchloride or fluoride

NOTE: If lapping cannot be performed thewedge or disc seating surface should beground using an automatic grinding machineFig 5.2 G. For major damage use 60-80 grit,diamond or Micron Alumina stick on abrasivediscs and finish with fine grit 180 and up. For minor imperfections use stick on abrasivemedium course 120 grit and finish with 180-220fine grit.

Figure 5.2G Wedge or disc AutomaticGrinding Machine



5.2.3.3 Seat Repairs

5.2.3.3.1 Gate & Parallel Slide Valves1. If seating faces are damaged, the body seat

must be corrected by lapping. Slight pitting,scratches or indentations no deeper than0.005” (0.1 mm) can be removed by lapping.If defects cannot be corrected by lapping, theseats should be ground using specializedautomatic grinding/lapping equipment. Velanrecommends a maximum of 0.015” (0.4 mm)per side that can be removed from a 10°seated valve, and 0.010” (0.25 mm) per sideon a 7° seated valve.

For parallel slide valves, a maximum of 0.040:(1 mm) per seat can be removed, see “NOTE”in Section 5.2.3.2 step 2. Grinding the seatusing automatic grinding equipment can saveconsiderable time, refer to Fig. 5.2H.For major damage use 60-80 grit, diamond orMicron Alumina stick on abrasive discs.For minor damage use 120-180 grit and for finishing, fine grit 220 and up can be used.For details contact our Customer ServiceDepartment.

2. In those cases where the automatic grindingand lapping machine is not employed, seatfaces must be repaired using a lapping plate.The plate should be made of cast iron if Figure 5.2H Automatic grinding lapping

machine for gate valve seatsand wedges

View A

View B

24



25

5.2.3.3.2 Globe, Needle, Stop andPiston Check Valves

1. Disassemble the valve as described in Section 7.3.2 for globe valves, Section 7.4 forstop check valves and Section 7.5 for pistoncheck valves. Inspect the disc and the seat forscratches, pitting marks or other damage.

Figure 5.2I Lapping plate

Cast ironlapping disc

Figure 5.2J Cast iron lapping disc

possible and should be large enough to coverthe face of the seat (Fig. 5.2I). Apply lappingcompound mixed with olive oil and distributeevenly over the plate. Lap seat by movinglapping plate in a circular motion on seat face. Lift the plate as often as possible to prevent accumulation of particles in one area and to allow for proper distribution of the lapping compound. Lap until both seats have smooth faces and then clean off the lapping compound very thoroughly with a suitablecleaning fluid such as acetone or alcohol.

NOTE: Velan recommend the use of clovercompound (silicon carbide) grade “E” medium course for minor imperfections andgrade “C” fine grit compound for finishing.

2. If there are indentations or pitting marks nodeeper than 0.005” (0.1 mm), a cast iron lapping disc (Fig. 5.2J) with the proper seatangle must be used with a suitable lappingcompound to roughen the surface first withthe use of a new or refurbished original disc(Fig 5.2K), use a fine lapping compound tofinal lap the disc and seat together.

NOTE: For body seat damage exceeding0.005” (0.12 mm) up to a maximum; for globeand needle, seat angle 15° 0.030” (0.76 mm)per side, for stop check and piston check seatangle 30° 0.040” (1 mm) per side can beremoved by grinding with the automaticgrinding machines Fig. 5.2L. For major seatdamage use 60-80 grit, diamond or micronAlumina stick on abrasive discs, and finishwith fine grit 180 and up. For minorimperfections use medium course 120 gritstick on abrasive discs and finish with fine grit,180 and up.

For the valve disc seating surface damageexceeding 0.005” (0.12 mm), remove up to



26

Figure 5.2K Original stem-disc assembly

Originalstem-discassembly

Guidingplate

maximum of: globe and needle disc angle 12°0.030” (0.76 mm) per side. For stop check andpiston check disc angle 27° 0.040”(1 mm) perside. Chuck and center the disc in a lathemachine, remove only as needed up to themaximum indicated above. The repaired discshould be mated fine lapped with the bodyseat as shown in Fig. 5.2K

IMPORTANT: A guiding plate for the stem is required to maintain alignment during the lapping operation. Refer to Fig 5.2K. It should be made of wood or any other suitable material to the same gasket dimensions as the bonnet.

The section of the plate where the stemextends through should be made 1/64” (0.4 mm) larger than the stem diameter.

3. Place a small quantity of lapping compoundmixed with olive oil and evenly distribute onthe two mating surfaces.

4. It is important to apply slight pressure whenlapping seats and to rotate in reciprocally. For best results, use an air or electric hand tool with adjustable speed and reciprocalmovement. The lap should be lifted frequentlyand turned to a new starting position so thatthe lapping will be rotated over a new area.

5. In order to ensure that the pressure is appliedevenly, it is necessary, on some valves, tosuspend the disc and stem assembly from acoil spring as shown in Fig. 5.2J.

6. Automatic grinding and lapping of seat facescan be done by specialized equipment Fig. 5.2L which is readily available at certainVelan authorized repair facilities. For furtherdetails on such operations, contact ourCustomer Service Manager.

Figure 5.2L Automatic reseater machine forgrinding / lapping globe seats

Figure 5.2M Blue ink test

5.2.3.4 Fitting of Repaired Parts

5.2.3.4.1 Gate Valves

1. After the seating faces of the wedge, discs, orseats have been relapped and cleaned, a blueink test is recommended before reassembly. A blueing ink should be distributed smoothlyand equally over the full circumferential sur-face of both sides of the wedge or discs (Fig.5.2M). Place the side of the wedge or disc pos-sessing the body serial number together withthe side of the seat also possessing the bodyserial number (these sides should have beenmarked-up during valve disassembly in accor-dance with Section 4.4, General AssemblyInformation. Preassemble the bonnet and stemnut. Engage the stem threads with stem nut.Slide the wedge T-slot into the stem T-head.Using a chain hoist slowly lower the entireyoke bonnet and wedge assembly into thebody. Secure the bonnet to body. Close thevalve manually using the handwheel and tight-en firmly. Release the tension by backing offhandwheel a few turns. Lift out of the valvebody and check for positive contact.

NOTE: If above procedure cannot be followeduse alternate method as follows: slide stem T-head into the wedge T-slot. Slowly lower thestem & wedge into the body. Tap a few timeson top of the stem using a plastic, brass or leadhammer. Lift out the stem & wedge and checkfor positive contact.

2. If a part cannot be repaired, new parts must befitted and installed. All spare part wedges aresupplied slightly oversized. In order to fit, theymust be ground or machined followed by ablue ink test to confirm 100% seating contact,and then finally lapped. Refer to Fig. 5.2N.NOTE: If the outside diameter of hardface andtop and bottom face-to-face dimensions of theold wedge are given to Velan, it is possible thatthere will be very little or no fitting required atthe site when replacing the part.

3. In some cases the seat angle may be lost whenthe seat is ground in the body. Therefore thewedge must be shimmed while the seat isbeing ground or machined. Shim only asmuch as required to obtain a full fit over thefull circumference of the seating faces.Determine new wedge dimensions. see Fig. 5.2N. Fig. 5.2O illustrates a wedge

with a full seating circumference, which isessential whenever fitting a wedge.

D

b

T

Figure 5.2N Wedge dimensions

B

t

d

Top wedge dimension

bottom wedge

dimension

Serial number of body

Serial number of body

NOTE:Seat dimensionB should betransferred towedge dimen-sion b± 0.005"(0.1mm)

T= (t-B) × D + Bd

27



28

Figure 5.2O Full seating circumference

1 2

3 4

Figure 5.2P Clearance verification

NOTE: Numbers refer to four locations to be checked by feeler gauge

4. When fitting a wedge, it is also important thatthe clearance between the wedge and thewedge guide slots be checked with a feelergauge at four locations, as shown in Fig. 5.2P.Ideally, the clearance on both sides should bethe same, however, a minimum clearance of0.005” (0.1 mm) at any position along thelength of the guide must be maintained.

5.2.3.4.2 Parallel Slide Valves

1. After the seating faces of the disc and seathave been relapped and cleaned with a suitable cleaning fluid such as acetone or alcohol, it is essential that the results be verified using a blue ink test, check for full circumferential contact. A light coating of blueink should be distributed smoothly and equally over the seating diameter of the disc.To maintain the disc concentric with the seat,place shim stock at the bottom of the valvebody and lower the disc. Using a wood disc, astud and nut and tension against the oppositeseat, refer to Fig. 5.2Q

NOTE: Ensure that the same match markeddisc and seat are being checked.

2. Release bolt tension and remove stud and nut,lift out the disc and check for positive contact(full seating circumference) Fig. 5.2R illustratesa disc with a full seating circumference, whichis essential whenever fitting a disc.

NOTE: Damages to the seat and disc exceed-ing 0.060” (1.5 mm) may require new part tobe replaced



stud & nut

shim stock

wood disc

Figure 5.2Q Paralllel slide Preperation for Blue Ink Test

5.2.3.4.3 Globe, Stop Check and Piston CheckValves

1. After the seating faces of the disc and seathave been relapped and cleaned with asuitable cleaning fluid such as acetone oralcohol, it is essential that the results beverified using a blueing test to check for fullcircumferential contact. A blue ink should bedistributed smoothly and equally over theseating diameter of the disc. Slowly lower thepart into the body and find the correct matingpoint of the faces. Fig. 5.2S illustrates a discwith a full seating circumference, which isessential whenever fitting a disc.

Figure 5.2S Tapered disc -Full seatingcircumference



Figure 5.2R Parallel SlideFull seating circumference

2. When fitting the disc, it is also important thatthe body inside diameter be checked forsufficient clearance to allow the disc to movefreely up and down. We recommend a visualexamination of the body wall. Any high spots,grooves or scratches should be polished witha fine emery cloth, or buffing wheel 120 - 180grit.

29

30

3. Verification of contact between the valve discand the stem is made by a radius on the endof the valve stem and is designed to give center loading for the disc as closely as possible. A hard thrust pad (Fig. 5.2T), whichcan be found in some designs, will helpprevent galling. On valves without a thrustpad, the bearing surface in the disc has a hardface deposit on it (Fig. 5.2U). If particlesget caught between the end of the valve stemand the disc, the center of the stem could be destroyed and the disc will not seat tightly.The contact surfaces of the stem and the discmust be checked first in leaky valves in orderto ensure that the disc-stem contact is in proper condition.

Figure 5.2U Tapered disc - Hardface deposit

Figure 5.2T Tapered disc - Thrust pad

Thrustpad

Hardfacedeposit



31

EXAMPLE:Torque = (Pressure × K1) + K2

Type = GateSize = 10" (250 mm)Pressure = 1125 psiK1 = 0.41K2 = 26Torque = (1125 × 0.41) + 26

= 487 ft⋅lb

Diagram 5.2A Closing torques

K 1gl

obe

K2K 1ga

te

Valve size

5.2.4 Backseat Repairs1. The following valves are equipped with an

integral or welded-in backseat in the bonnet(Fig. 5.2V).a) Gate valveb) Parallel slide valvec) Globe valved) Needle valvee) Stop check valve

5.2.3.5 Seat Tightness - Closing Torques

Even with a brand new valve, seat tightness willonly be achieved when sufficient load has beenapplied to the wedge or disc. This load varies withthe pressure differential against which the valvehas to be closed or opened.

As a guideline, Diagram 5.2A can be used toestimate the torque required to open or close avalve against a given differential pressure. Thetorque calculated is that torque which has to beapplied directly to the valve stem and does nottake into account any mechanical advantage suchas that achieved with a gear actuator, etc.

NOTE: Diagram 5.2A serves only as a generalguide line to determine approximate closingand opening torques required. It is not to beused in e.g. motor actuator, bevel gear orpneumatic actuator sizing.



CAUTION: The use of wheel wrenches,cheater bars, etc., is quite common.However, it must be emphasized that thesedevices should be used with discretion,and then only to achieve approximately thetorque as calculated from Diagram 5.2A.

BOLTING MATERIALTHREAD B7, A-574, 630 B8, B8MSIZE

ft.lb. Nm ft.lb. Nm3⁄8 – 16 UNC 30 41 10 147⁄16 – 14 UNC 45 61 15 201⁄2 – 13 UNC 75 102 25 349⁄16 – 12 UNC 105 142 35 485⁄8 – 11 UNC 145 197 50 683⁄4 – 10 UNC 255 346 85 1157⁄8 – 9 UNC 405 549 135 183

1 – 8 UNC 615 834 205 27811⁄8 – 8 UN 900 1221 300 40711⁄4 – 8 UN 1270 1723 425 57613⁄8 – 8 UN 1725 2340 575 78011⁄2 – 8 UN 2280 3092 760 103115⁄8 – 8 UN 2935 3981 980 132913⁄4 – 8 UN 3715 5039 1240 168217⁄8 – 8 UN 4615 6259 1540 20892 – 8 UN 5650 7663 1880 2550

Table 5.3A Torque Values for yoke/actuator/bonnet bolting

Note :

(1) Torque tolerance ±10%(2) For temperatures above 750°F (400°C)

use 75% of the values.(3) Maximum temperature for 630 is 650°F (345°C)(4) Above torque values are with the bolts lubricated

32

0204

13

Figure 5.2W Upside down bonnet and stem

5.3 TORQUE VALUES - ACTUATOR,YOKE/BONNET BOLTING

The torque values shown in Table 5.3A are for allbolting other than bonnet/body retaining boltingor packing flange studs.

Integral

Weld-in

Figure 5.2V Integral or welded in backseats

02 - Bonnet04 - Stem13 - Pkg rings



The above valves have a stem with a backseatshoulder. This should sit perfectly against thebonnet backseat to make a perfect seal. It ispossible that this seal may leak due to scratches,pitting or other reasons. Therefore this seal mustbe repaired by relapping the mating faces.

2. Dismantle the valve in accordance withSections 6.4.2 (gate), 7.3.2 (globe),7.4 (stop check), and 8.3.2 (parallel slide).

3. Place the bonnet and stem upside down asshown in Fig. 5.2W and insert two or threepacking rings in the packing chamber to serveas a guide for the centralizing of the stem tothe backseat. Add a fine mixture of lappingcompound between the two mating faces.Gently rotate the stem back and forth andoccasionally lift the stem slightly and rotatearound backseat so that lapping will be over a distributed new area.

NOTE: On larger valves, the stem must besupported so that the weight of the stem does not cause a groove or galling on the backseat.

4. When the lapping procedure is finished, alllapping compound must be removed with asuitable cleaning fluid such as acetone or alcohol.

5. Velan recommends that the lapping procedurebe verified for full contact by blue ink one ofthe two faces. After verification, the surfacesmust be cleaned again.

NOTE: Velan recommends the use of “clover”compound (silicone carbide) grade “E” medium coarse and or grade “C” fine grit

33

Rotated 90ºfor clarity

35A

26B

29A34

17D

17C

15B 16B

36A36B

36C11

12

33

30

88

28

29B

03

26A

2529

17A

16 1519B

64

62

02

19

13B13A

63

04

05

01

14

18

66

10

09

Figure 6.1A Forged bolted bonnet gate valve

6.1 GATE VALVE ASSEMBLY DRAWING

PARTS DESCRIPTION01 - Body02 - Bonnet03 - Yoke04 - Stem05 - Wedge09 - Seat10 - Wedge guide11 - Packing flange12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)14 - Lantern ring15 - Stud15B - Packing stud16 - Nut16B - Packing nut17A - HSH cap screw17C - HSH cap screw17D - HSH cap screw18 - Backseat (stellite 6)19 - Gasket19B - Gasket25 - Torque arm26A - Key26B - Key28 - Yoke housing cover29 - Bearing29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35A - Set screw36A - Belleville washer36B - Guide sleeve36C - Guide bushing62 - Leak-off pipe63 - Junk ring64 - Blow out plug66 - Name plate88 - Stem nut

GATE VALVE VI

34

Figure 6.2 Typical exploded view-gate valve

6.2 EXPLODED VIEWS

PARTS DESCRIPTION01 - Body02 - Bonnet03 - Yoke04 - Stem05 - Wedge09 - Seat10 - Wedge guide11 - Packing flange12 - Gland bushing13 - Pkg ring14 - Lantern ring15 - Body-bonnet stud15B - Packing flange stud16 - Body-bonnet nut16B - Packing flange nut17A - Yoke-bonnet cap screw17C - Torque arm cap screw17D - Socket head cap screw19 - Gasket19B - Blow-out gasket25 - Torque arm26A - Torque arm key26B - Handwheel key28 - Yoke housing cover29 - Bearing29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35A - Set screw36A - Belleville washer36B - Guide sleeve62 - Leak-off pipe63 - Junk ring64 - Blow out plug88 - Yoke nut

VI GATE VALVE

35

6.3 GASKET REPLACEMENT

Follow warning instructions in Section III beforebeginning disassembly. If valve is equippedwith a gear or motor actuator, see Appendix fordisassembly of actuators. As a generaldisassembly progresses, place matching marks onparts so that the same orientation of parts can bemaintained at reassembly.

1. The valve should be in a partially open position.

2. Before proceeding with disassembly of valves,check if the valve is equipped with a leakoffoption (62). If so, disconnect it first. Leakoff pipes should be unscrewed or cutapproximately 6” (150 mm) from the bonnetside and not at the welded joint on the bonnet.

3. Remove body/bonnet nuts (16)

Note: If a valve has been in high temperatureservice for extensive periods of time, the nutssometimes becomes seized to the stud.Tight threads can be loosened by applyingpenetrating oil or heat to the nut and working itfree. As a last resort, a hacksaw, cutting torchor cold chisel can be used to cut the nut awayfrom the stud.

4. Once all the nuts are removed, the entireyoke/bonnet assembly can be lifted from thevalve body as shown in Fig. 6.3A.

5. Remove gasket (19).

6. The gasket recess seating faces on the body andbonnet must first be checked for scratches, whichcan normally be removed with an emery cloth.The faces should then be solvent degreased anddried before assembly. Approved solvents areAcetone and Alcohol.

7. Install body-bonnet studs if previously removed.Place a new gasket preferably on the bonnetusing a chain hoist. Carefully lower the entirebonnet assembly together with the stem &wedge and observe the match marks.

NOTE: If only yoke/bonnet assembly has beenremoved follow step (8). If the yoke (3) has beenremoved from the bonnet follow step (9)

8. IMPORTANT: Use a chain block or come alongto move heavy yoke/bonnet or cover.

Lift yoke/bonnet assembly onto stem and partially lower. Place the junk ring (63) (ifapplicable) into the packing chamber with theknurled side down. Before completely settingbonnet down onto the valve body the lanternring (14) (if applicable), gland bushing (12),

Figure 6.3A Disassembly for gasket replacement

3429A 26B 35A 88 30

33

17D

17C

15B 16B

36B

36A

36C

11

12

28

29B

03

26A

29

25

17A

62

02

13A 13B

63

04

05

19

01

64

19B

16

14

18

15

66

10

09


PARTS DESCRIPTION01 - Body02 - Bonnet03 - Yoke04 - Stem05 - Wedge09 - Seat10 - Wedge guide11 - Packing flange12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)14 - Lantern ring15 - Stud15B - Stud16 - Nut16B - Nut17A - HSH cap screw17C - HSH cap screw17D - HSH cap screw18 - Backseat (stlt. 6)19 - Gasket19B - Gasket25 - Torque arm26A - Key26B - Key28 - Housing cover29 - Bearing29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35 - Set screw36A - Belleville washer36B - Guide sleeve36C - Guide bushing62 - Leak-off pipe63 - Junk ring64 - Blow out plug66 - Name plate88 - Stem nut

GATE VALVE VI

VI GATE VALVE

36

Figure 6.4A Torque arm 4 types

TYPE I

TYPE III

TYPE II

TYPE IV

PARTS DESCRIPTION15D - Stud (torque arm)16D - Nut (torque arm)17C - Cap screw (torque arm)25 - Torque arm26A - Key (torque arm)29 - Bearing35 - Set screw

packing flange (11), and type I or II torque arm(25) (if so equipped) must first be positionedcorrectly. This properly secures stem in place.Align bonnet with body as they were prior todisassembly and carefully lower onto body.

NOTE: Once on the body the bonnet must notbe rotated for alignment purposes as thiscould damage the gasket.

9. Place yoke (3) over bonnet and partially lower.Align yoke with bonnet before setting yokedown. Install yoke/bonnet cap screws (17a).

NOTE: Care should be taken to prevent thegasket from getting damaged when aligningheavy yoke/bonnet assembly on the body.

10. Apply recommended lubricant to body/bonnetstuds (15) and bottom flat of nuts (16). Installand tighten body/bonnet nuts in strict accor-dance with Section 4.5.2, Torque Procedure.

6.4 TOTAL DISASSEMBLY OF GATE VALVES

6.4.1 General

Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped witha gear or motor actuator, see Appendix for disas-sembly of actuators. As a general disassemblyprogresses, place matching marks on parts so thatthe same orientation of parts can be maintained atreassembly.

6.4.2 Diassembly of Body/Bonnet and Wedge/Stem

Follow steps 1 through 5 in Section 6.3, GasketReplacement.

6. The valve is now ready for inspection andrepairs of wedge, seat, etc.

7. During inspection check the body/bonnet stud (15) for damage. Studs may have been damaged when removing seized nuts or whenlifting the yoke/bonnet assembly. If studs aredamaged, remove and replace them.

a) Screw on the two nuts.b) Lock the bottom nut to the top nut.c) Turn the bottom nut to remove the stud.d) Take the new stud and apply Antiseize

compound to it. See Table 4.3Afor recommended lubrication.

e) Screw in the stud and tighten.

8. Remove packing flange nut (16b) and live-loading option.

NOTE: If the valve is equipped with live-loading, including guide sleeves (36b) and on Belleville washers (36a) as shown inFig. 5.1J make note of the order of these partsso that at reassembly they will return in thesame order.

37

9. Remove torque arm. There are four types oftorque arms, see Fig. 6.4A:

Type I: One piece with bearing,Type II: One piece without bearing,Type III: Two piece with bearing,Type IV: Two piece without bearing.

a) Removal of Types I and II:

Loosen the cap screw (17c) and remove.Slide torque arm (25) up along stem andremove torque arm key (26a) from stem.Torque arm will not come off at this point,but you must make sure that the torque armslides freely over the stem.

b) Removal of Types III and IV:

Loosen hex nuts (16D), pull torque armapart and remove torque arm key (26A)from stem. The torque arm will come totally off assembly at this point.

10. Remove packing rings (13) according toSection 5.1.2, Packing Ring Removal on Line.

11. Remove stem (4) by turning it out of the stemnut (88). When the stem is disengaged from

Figure 6.4D Valve top works disassembly

04

35A

34

29A

26B

88

29B

17D

30

33

28

03

Figure 6.5A Valve top works assembly

35A

26B

88

34

29B

17D

30 33

28

29A

03

04

PARTS DESCRIPTION03 - Yoke04 - Stem17D - HSH cap screw26B - Key28 - Housing cover29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35A - Set screw88 - Stem nut

the stem nut, pull the stem out through thebottom of the yoke/bonnet assembly.

NOTE: When removing the stem, the Type I andII torque arm (25), packing flange (11), glandbushing (12), lantern ring (14) and junk ring (63)will be free and can be removed from the assembly.

12. The valve and parts are now ready for inspection, repairs and replacement of stem,torque arm, etc.

6.4.3 Disassembly of Top Works (Fig. 6.4D)

Follow warning instructions in Section III beforebeginning top works disassembly.

1. If line pressure is maintained in the valve,backseat the valve in fully open position beforestarting any disassembly.

2. Remove small set screw (35A) in handwheel nut(30), then unscrew handwheel nut.

3. Remove handwheel (33).

4. Remove housing cover bolting (17D) and removehousing cover (28).

5. Remove first set of bearings (29A) (3 pieces).

6. Unscrew stem nut (88) from the stem (04).

7. After the stem nut has been removed, removesecond set of bearings (29B) (3 pieces).

8. Now valve and parts are ready for inspection,repairs and replacement of stem nut, bearing, etc.

GATE VALVE VI

03 - Yoke04 - Stem17D - HSH cap screw26B - Key28 - Housing cover29A - Bearing

PARTS DESCRIPTION29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35A - Set screw88 - Stem nut

38

6.5 ASSEMBLY

6.5.1 Top Works Assembly (Fig. 6.5A)

1. Apply new grease to threaded portion of stem(04) above top flange on yoke (03).

2. Mount second set of newly-greased bearings(29B) in recess of yoke.

NOTE: Bottom race must fit loosely aroundstem nut and top race must be tight aroundstem nut.

3. Apply new grease to internal thread in stemnut (88) and screw stem nut on stem.

4. Mount first set of newly greased bearings(29A) on stem nut.

Note: Bottom race must fit tightly aroundstem nut and top race must be loose.

5. After the bearing and stem nut are in place,mount housing cover (28) on top and boltdown with the housing cover bolting (17D).Bolting must be torqued down in accordancewith the values in Table 5.3A.

6. Insert handwheel key (26b) in stem nut keywayand mount handwheel (33).

7. Return handwheel nut (30) and tighten. Use handwheel nut set screw (35A) to lockhandwheel nut in place.

8. Inject more new grease into housing coverthrough the grease fitting (34) on side of housing cover.

9. Verify operation by cycling at least once fromfully open to fully closed position.

6.5.2 Body/Bonnet & Wedge/Stem Assembly(Valve Internal & Mid-Section)

1. Place wedge on T-head of stem check ensuringthat stem T-head and wedge T-slot do nothave a tight fit. To avoid interference, stemT-head should be able to rock freely. Positionmarked up side of wedge with marked up sideof body seat (both sides possessing body serial number). Also ensure that stem torquearm key way is in the same position as notedbefore disassembly. Lower the stem/wedgeinto the valve body.

2. Place a new gasket in recess on top mountingface of body in accordance with cleanlinessand lubrication instruction as described inSection 6.3, Gasket Replacement.

3. IMPORTANT: Use a chain block or comealong to move heavy bonnets.

Lift bonnet onto stem and partially lower.Place the junk ring (63) (if applicable) into thepacking chamber with the knurled side down.Before completely setting bonnet down ontothe valve body the lantern ring (14) (if applicable), gland bushing (12), packing flange (11), and Type I or II torque arm (25) (if so equipped) must first be positioned correctly. This properly secures stem in place.Align bonnet with body as they were prior to disassembly and carefully lower onto body.

4. Place yoke (3) over bonnet and partially lower.Align yoke with bonnet before setting yokedown. Install yoke/bonnet cap screws (17A).

NOTE: Care should be taken to prevent thegasket from getting damaged when aligningheavy yoke/bonnet assembly on the body.

5. Align torque arm on stem (4) and make surethe key (26A) is fitting properly in the stem,torque arm keyway and yoke channel. Torquein accordance with Torque Table 5.3A.

6. Apply recommended lubricant to valve stemthreads (4), to body/bonnet studs (15), andbottom flat of nuts (16). Install and tightenbody/bonnet nuts in strict accordance withSection 4.5.2, Torque Procedure.

7. Mount top works assembly in accordance withSection 6.5.1 and open valve fully to its backseated position.

NOTE: If equipped with motor actuator ormanual gear operator see Appendix andreassemble in reverse of disassembly.

8. Repacking with graphite packing rings followprocedure Section 5.1.4 (valves without leak-off connections) or Section 5.1.5 (valveswith a leak-off connection).

NOTE: If the valve is equipped with a live-loading option, live-loading parts must be placed in the same order as noted in disassembly.

9. Verify operation by cycling at least three timesfrom fully open to fully closed position.

VI GATE VALVE

39


30

33

26B

29A

34

03

26A

25

29

04

17A

16 15

35

15C 16C

28

29C

88

17C16B15B

36B36A

36C

12

11

13B13A

62 02

14

19

41

06

19B

64

63

66

40

01

Figure 7.1A Forged bolted bonnet globe valve

Figure 7.1B Piston check valve

7.1 GLOBE & PISTON CHECK VALVE ASSEMBLY DRAWING

01

06

16 15

19

66

59For steam service

For liquid service

50

01 - Body02 - Bonnet03 - Yoke04 - Stem06 - Disc11 - Packing flange12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)14 - Lantern ring15 - Stud15B - Stud15C - Stud16 - Nut16B - Nut16C - Nut17A - HSH cap screw17C - HSH cap screw19 - Gasket19B - Gasket25 - Torque arm

01 - Body06 - Disc15 - Stud16 - Nut

26A - Key26B - Key28 - Housing cover29 - Bearing29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35 - Set screw36A - Belleville washer36B - Guide sleeve36C - Guide bushing40 - Disc union41 - Stem collar62 - Leak-off pipe63 - Junk ring64 - Blow out plug66 - Name plate88 - Stem nut

19 - Gasket50 - Cover59 - Equalizer pipe66 - Name plate

GLOBE VALVE VII

PARTS DESCRIPTION

PARTS DESCRIPTION

40


Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped witha gear or motor actuator, see Appendix fordisassembly of actuators. As a generaldisassembly progresses, place matching marks on parts so that the same orientation of parts canbe maintained at reassembly.

1. The valve should be in a partially openposition.

2. Before proceeding with disassembly of valves,check if the valve is equipped with a leakoffoption (62). If so, disconnect it first.Leakoff pipes should be unscrewed or cutapproximately 6” (150 mm) from the bonnetside and not at the welded joint on thebonnet.

3. Remove body/bonnet nuts (16).

NOTE: If a valve has been in high temperatureservice for extensive periods of time, the nutssometimes becomes seized to the stud.Tight threads can be loosened by applyingpenetrating oil or heat to the nut and workingit free. As a last resort, a hacksaw, cuttingtorch or cold chisel can be used to cut the nutaway from the stud.

4. Once all the nuts are removed, the entireyoke/bonnet assembly can be lifted from thevalve body as shown in Fig. 7.2A. The stem(4) and disc (6) will come out in one piece withthe yoke/bonnet assembly.


6. The gasket recess seating faces on the bodyand bonnet must first be checked forscratches, which can normally be removedwith an emery cloth. The faces should then besolvent degreased and dried before assembly.Approved solvents are Acetone and Alcohol.

7. Install body/bonnet studs if previouslyremoved. Place a new gasket preferably onthe bonnet. Using a chain hoist, carefullylower the entire yoke/bonnet assembly together with the stem and disc and observethe match marks.

NOTE: If only yoke/bonnet assembly has beenremoved follow step (9).

8. If the valve being assembled is a stop-checkvalve, insert disc (6) into valve body andspring option (46) into disc. Lower and insert

Figure 7.2A Disassembly for gasket replacement

35

16C15C

28

29B

88

15B 16B

17C

36B

36A

36C

11

12

13A 13B

62 02

33

30

26B

34

29A

03

26A

25

29

04

17A

16

19B

64

63

14

4041

0615

19 66

01

Rotated 90° for clarity

01 - Body02 - Bonnet03 - Yoke04 - Stem06 - Disc11 - Packing flange12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)14 - Lantern ring

15 - Stud15B - Stud15C - Stud16 - Nut16B - Nut16C - Nut17A - HSH cap screw17C - HSH cap screw19 - Gasket19B - Gasket25 - Torque arm

26A - Key26B - Key28 - Housing cover29 - Bearing29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35 - Set screw

36A - Belleville washer36B - Guide sleeve36C - Guide bushing40 - Disc union41 - Stem collar62 - Leak-off pipe63 - Junk ring64 - Blow out plug66 - Name plate88 - Stem nut

VII GLOBE VALVE

PARTS DESCRIPTION

41

stem into spring and disc. Place a new gasketin recess on top mounting flange of body inaccordance with cleanliness and lubrication instruction.

9. Lift the yoke/bonnet assembly and lower ontostem through the bottom of bonnet.

NOTE: For heavier bonnets use a chain blockor come along

Place junk ring (63), if applicable, with theknurled side downward into the packingchamber. The lantern ring (14), if applicable,gland bushing (12), packing flange (11), andType I or Type II torque arm (25), if soequipped must be in correct position beforecompletely setting down bonnet onto thevalve body.

10. Line up bonnet/yoke assembly with body andlower onto the body.

NOTE: Care should be taken to prevent thegasket from getting damaged when aligningheavy bonnet assembly on the body.

11. Apply recommended lubricant to body/bonnetstuds (15) and bottom flats of nuts (16). Install and tighten body/bonnet nuts in strict accordance with Section 4.5.2, TorqueProcedure.

7.3 TOTAL DISASSEMBLY OF GLOBE VALVES

7.3.1 General

Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped with a gear or motor actuator, see Appendix for disassembly of actuators. As a generaldisassembly progresses, place matching marks on parts so that the same orientation of parts canbe maintained at reassembly.

7.3.2 Disassembly of Body/Bonnet andDisc/Stem Union

Follow steps 1 through 4 inSection 7.2, Gasket Replacement.

5. The stem (4) and disc (6) will come out in onepiece with the yoke/bonnet assembly. Thiscan be disassembled with the stem remainingin the yoke/bonnet assembly or the stem anddisc assembly can be removed.

6. The connection between the stem (4) and thedisc (6) is made by the use of a disc union (40)and the stem collar (41). To remove this connection, break the tack welds by using ahacksaw, a small sharp chisel, or by grinding.

7. After the tack welds are removed, unscrew thedisc union from the disc, pull the disc off thestem and remove the stem collar (two pieces)from the stem. Check inside the disc. Somediscs will have a hardfacing deposit at the bottom center or they will have a small thrustpad (42).See Fig. 7.3A

8. Now the disc can be repaired or replaced.


10. The valve is now ready for inspection andrepairs.

11. During inspection check the body/bonnet stud (15) for damage. Studs may have been damaged when removing seized nuts or whenlifting the yoke/bonnet assembly. If studs aredamaged, remove and replace them.

a) Screw on the two nuts.

b) Lock the bottom nut to the top nut.

c) Turn the bottom nut to remove the stud.

d) Take the new stud and apply Antiseize com pound to it. See Table 4.3A for recommendedlubrication.

e) Screw in the stud and tighten.Figure 7.3A Disc unit, exploded view

PARTS DESCRIPTION04 - Stem06 - Disc40 - Disc union41 - Stem collar42 - Thrust pad

GLOBE VALVE VII

42

12. Remove packing flange nut (16B) and live-loading option.

NOTE: If the valve is equipped with live-loading, including guide sleeves (36B) and Belleville washers (36A) as shown in Fig. 5.1J, make note of the order of these partsso that at reassembly they will return in thesame order.

13. Remove torque arm. There are four types oftorque arms, see Fig. 7.3B:

Type I: one piece with bearing,Type II: one piece without bearing,Type III: two piece with bearing,Type IV: two piece without bearing.

a) Removal of Type I and II:

Loosen the cap screw (17C) and remove.Slide torque arm (25) up along stem andremove torque arm key (26A) from stem.Torque arm will not come off at this point,but you must make sure that the torque armslides freely over the stem.

b) Removal of Types III and IV:

Loosen hex nuts (16D), pull torque arm apart and remove torque arm key (26A) from stem. The torque arm will come totallyoff assembly at this point.

14. Remove packing rings (13) according toSection 5.1.2, Packing Ring Removal On-Line.

15. Remove stem (4) by turning it out of the stemnut (88). When the stem is disengaged fromthe stem nut, pull the stem out through the bottom of the yoke/bonnet assembly.

NOTE: When removing the stem, theType I or II torque arm (25), packing flange (11),gland bushing (12), lantern ring (14) and junkring (63) will be free and can be removed fromthe assembly.

16. The valve and parts are now ready forinspection, repairs and replacement of stem,torque arm, etc.

Figure 7.3B Torque arm 4 types

TYPE I

TYPE III

TYPE II

TYPE IV


VII GLOBE VALVE

For liquid service

For steam service

06 15

01

19

66

59

43

7.3.3 Disassembly of Top Works(Fig. 7.3C)

Follow warning instructions in Section III beforebeginning top works disassembly.

1. If line pressure is maintained in the valve,backseat the valve in fully open position beforestarting any disassembly.

2. Remove small set screw (35A) in handwheelnut (30), then unscrew handwheel nut.


4. Remove housing cover bolting (17D) andremove housing cover (28).


6. Unscrew stem nut (88) from the stem.

7. After the stem nut has been removed, removesecond set of bearings (29B) (3 pieces)

8. Valve and parts are now ready for inspection,repairs, and replacement of stem nut, bearing, etc

7.4 TOTAL DISASSEMBLY OF STOP CHECK VALVES

Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped witha gear or motor actuator, see Appendix fordisassembly of actuators. As a generaldisassembly progresses, place matching markson parts so that the same orientation of parts canbe maintained at reassembly.


5. The stem is not attached to the disc. The disc(6) and spring option (46) must be lifted fromthe valve body after the yoke/bonnet assemblyhas been removed, as shown in Fig. 7.4A.


7. The valve is now ready for inspection andrepairs of disc, seat, etc.

8. Continue disassembly of stop check valvefollowing steps 11 to 16 in Section 7.3.2,

Disassembly of Body/Bonnet and Disc/Stemand steps 1 through 8 in Section 7.3.3,

Disassembly of Top Works.

Figure 7.3C Valve top works disassembly

04

35A

34

29A

26B

88

29B

17D

30

33

28

03

01 - Body 19 - Gasket06 - Disc 59 - Equalizer pipe15 - Stud 66 - Nameplate

Figure 7.4A Forged stop check valve


GLOBE VALVE VII

PARTS DESCRIPTION

44

7.5 TOTAL DISASSEMBLY OF PISTON CHECK VALVE

1. Remove body/cover nuts (16).

2. Once all the nuts are removed, the cover (50)and gasket can be lifted from the valve bodyas shown in Fig. 7.5A.

3. Lift the disc (6) and spring option (46) from thevalve body.

7.6 ASSEMBLY

7.6.1 Top Works Assembly

1. Apply new grease to threaded portion of stem(04) above top flange on yoke (03).


NOTE: Bottom race must fit loosely aroundstem nut and top race must be tight aroundstem nut. See Fig. 7.6A.

3. Apply new grease to internal thread in stemnut (88) and screw stem nut on stem.

4. Mount first set of newly greased bearings(29A) on stem nut.

Note: Bottom race must fit tightly aroundstem nut and top race must be loose.

5. After the bearing and stem nut are in place,mount housing cover (28) on top and tie downwith the housing cover bolting (17D). Boltingmust be torqued down in accordance with thevalues in Table 5.3A.

6. Insert handwheel key (26B) in stem nut keywayand mount handwheel (33).





35A

26B

88

34

29B

17D

30 33

28

29A

03

04

Forliquidservice

Forsteamservice

50

06

01

16

19

15

66

59

01 - Body 16 - Nut 59 - Equalizer pipe06 - Disc 19 - Gasket 66 - Nameplate15 - Stud 50 - Cover

Figure 7.5A Forged piston check valve



VII GLOBE VALVE

PARTS DESCRIPTION

45

7.6.2 Body/Bonnet and Disc/Stem Assembly(Valve Internal and Mid-Section)

1. Install small thrust pad (42) into disc so thatit fits into recess in bottom of disc (6), see Fig. 7.3A. Place stem collar (41) aroundgroove on stem (4). Install stem and stemcollar in disc and tighten down with discunion. Check if disc can be rotated. If disc can be rocked, it is correctly installed on stem.The rocking will allow the disc to self-alignitself to the seat.

Tack weld disc union to disc in three or fourplaces depending on the valve size. Checkagain to see if the disc can rock after tackwelding has cooled and lower disc/stem intovalve body.

2. If the valve being assembled is a stop-checkvalve, insert disc (6) into valve body andspring option (46) into disc. Lower and insertstem into spring and disc. Place a new gasketin recess on top mounting fare (flange) ofbody in accordance with cleanliness andlubrication instruction as described inSection 7.2, Gasket Replacement.

3. Lift the bonnet and lower onto stem throughthe bottom of bonnet (NOTE: For heavier bonnets use a chain blockor come along) placing junk ring (63),if applicable, with the knurled side downwardinto the packing chamber. The lantern ring(14), if applicable, gland bushing (12), packingflange (11), and Type I or II torque arm (25), ifso equipped must be in correct position beforecompletely setting down bonnet onto thevalve body.

4. Line up bonnet/yoke assembly with body andlower onto the body.

NOTE: Care should be taken to prevent thegasket from getting damaged when aligningheavy bonnet assembly on the body.

5. Mount Type I or Type II torque arm (if soequipped) on stem (4) and make sure the key(26A) is fitting properly in the stem, torquearm keyway and yoke channel. Torque inaccordance with Torque Table 5.3A.

6. Apply recommended lubricant to valve stemthreads (4) to body/bonnet studs (15) and bottom flats of nuts (16). Install and tightenbody/bonnet nuts in strict accordance withSection 4.5.2, Torque Procedure.

7. Mount top works assembly in accordance withSection 7.6.1 and open valve fully to its backseated position.

NOTE: If equipped with motor actuator ormanual gear operator see Appendix andreassemble in reverse of disassembly.

8. Repacking with graphite packing rings followprocedure Section 5.1.4 (valves without leak-off connection) or Section 5.1.5 (valveswith leak-off connection).

NOTE: If the valve is equipped with a live-loading option, live-loading parts mustbe placed in the same order as noted in disassembly.


GLOBE VALVE VII

46

8.1 PARALLEL SLIDE VALVE ASSEMBLY DRAWING


35

33

35A

17D

0403

17B

15B 16B

11

12

13A 13B

02

18

19

01

49

30

26B

34

28

29A

29B

88

25

26A

17A

15 16

66

10

45

46

43

09

07

01 - Body02 - Bonnet03 - Yoke04 - Stem07 - Disc09 - Seat10 - Wedge guide11 - Packing flange12 - Gland bushing13A - Pkg ring (ends)13B - Pkg rings (inter)15 - Stud15B - Stud16 - Nut16B - Nut17A - HSH cap screw17C - HSH cap screw17D - HSH cap screw18 - Backseat 19 - Gasket25 - Torque arm26A - Key28 - Housing cover29A - Bearing29B - Bearing30 - Handwheel nut33 - Handwheel34 - Grease fitting35 - Set screw43 - Disc carrier45 - Retaining ring46 - Spring49 - Stroke limiter66 - Name plate88 - Stem nut

Figure 8.1A Forged bolted bonnet parallel slide valve

VIII PARALLEL SLIDE VALVE

PARTS DESCRIPTION


Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped with a gear or motor actuator, see Appendix for disassembly of actuators. As a general disassembly progresses, place matching marks on parts so that the same orientation of parts can be maintained at reassembly.

1. The valve should be in a normally closed position.

2. Before proceeding with disassembly of valves,check if the valve is equipped with a leakoffoption (62). If so, disconnect it first. Leakoffpipes should be unscrewed or cut approximately 6” (20mm) from the bonnet side and not at the welded joint on the bonnet.

3. Loosen packing flange nuts (16B) and removepacking rings (13A & 13B) in accordance withSection 5.1.2, Packing Ring Removal On-Line.Remove torque arm. There are four types oftorque arms see Fig. 8.2A

a) Removal of Type I and II:Loosen the cap screw (17C) and remove.Slide torque arm (25) up along stem andremove torque arm key (26A) from stem.Torque arm will not come off at this point,but you must make sure that the torquearm slides freely over the stem.

b) Removal of Types III and IV:Loosen hex nuts (16D), pull torque armapart and remove torque arm key (26A) from stem. The torque arm will cometotally off assembly at this point.

IMPORTANT: Please note that the torque armassembly should not be allowed to comeloose during valve operations. This is crucialto maintain the alignment of the stem T-headin the disc-carrier.

PARALLEL SLIDE VALVE VIII

Figure 8.2A Torque arm 4 types

TYPE I

TYPE III

TYPE II

TYPE IV


47

48


4. Velan parallel slide valves have two types ofstroke limiters. Stroke limiter Type I (Fig. 8.2B) is mounted on top of the stem andfixed with a stud. Stroke limiter Type II (Fig. 8.2C) is directly threaded to the stem andsecured via a set screw in the stem groove. Stroke Limiter Type I (Fig. 8.2B):Measure the distance, dimension A, the stud(15) extends out of the top of the limiter (49).

Stroke Limiter Type II (Fig. 8.2C):Measure the distance from top of stem to thestroke limiter and record this value. This distancemust be noted because the distance regulates theclosed position of the parallel slide valve.

5. After the distance has been noted, removestroke limiter (49).

6. Remove the small set screw (35A) from thehandwheel nut (30). Unscrew handwheel nut.

7. After the handwheel nut has been removed,pull off the handwheel (33).

8. Loosen and remove housing cover bolting(17D). Lift housing cover (28) up over stem nut(88) and stem (04).

9. Remove first set of bearings (29A), (3 pieces)Refer to Fig. 8.1A

10. Unscrew stem nut (88) from stem (4).

11. After the stem nut has been removed, removesecond set of bearings (29B), (3 pieces).

12. Remove body/bonnet nuts (16).

13. Once all the nuts are removed, the entireyoke/bonnet assembly can be lifted from thevalve body as shown in Fig. 8.2D.

NOTE: When lifting the yoke/bonnet assembly, the stem and discs must stay inthe valve body. It is possible that the springs,which are between the two discs, could fallinto the valve body. One must be careful notto allow the discs to open up.

14. Remove gasket (19) and replace with new spiral gasket in recess on top mounting face of body. Follow cleanliness and lubricationinstruction. Refer to Fig. 8.2D and lubricate allstem threads

15.. Line up the bonnet/yoke assembly with thebody and lower onto the body. It is extremelyimportant that one prevents the gasket frombecoming damaged when aligning the heavybonnet assembly onto the body.

NOTE: When lowering the bonnet/yoke assembly, place the junk ring (63) with theknurled side downward into the packing chamber. The lantern ring (14), gland bushing(12), packing flange (11), and Type I or IItorque arm (25) must be in correct positionsbefore stem enters top flange on yoke.

16. Apply recommended lubricant to body/bonnetstuds (15) and then install body/bonnet nuts(16). Tighten body/bonnet nuts in strict accordance with Section 4.5.2, TorqueProcedure.

CAUTION: Do not tighten body/bonnet nutswhen discs are in a fully closed position.

Figure 8.2B Stroke limiter Type I

04 - Stem15 - Stroke limiter stud17 - Stroke limiter cap screw26B - Handwheel key30 - Handwheel nut33 - Handwheel35A - Handwheel

nut set screw49 - Stroke limiter

33

35A

26B

17D

88

49

35

30

28

34

Figure 8.2C Stroke limiter Type II

PARTS DESCRIPTION 33 - Handwheel34 - Grease fitting

03 - Yoke 26A - Key 35 - Set screw04 - Stem 28 - Housing cover 35A - Set screw17D - HSH cap 30 - Handwheel nut 49 - Stroke limiter

screw 31 - Lock washer 88 - Stem nut

PARTS DESCRIPTION

49

17. Now continue step-by-step reassembly procedures as described in Section 8.4.1, TopWorks Assembly.

18. Repack valve in accordance with Section 5.1.4(valves without a leak-off connection) andSection 5.1.5 (valves with a leak-off connection).

19. Mount packing flange nut (16B) and live-loading option (if so equipped) andtorque down in accordance with Section5.1.6, Packing Torques.

NOTE: If the valve is equipped with live-loading option, live-loading parts must returnin the same order as noted in disassembly.

20. Verify operation by cycling at least threetimes from fully open to fully closed position.

8.2.1 Alternate Gasket Replacement Procedure

1. For disc type I, III, IV Fig. 8.3B & D the valveshould be in a normally closed position.

2. Remove body-bonnet nuts (16) and matchmark body-bonnet.

3. Using a hoist and a sling wrapped around theyoke, lift the entire bonnet-yoke assemblytogether with the stem and disc until thebonnet just clears body-bonnet studs (15).

4. Remove 3 or 4 body studs (15) using a discclamp or standard C clamp Fig 8.3A. Clampthe disc and tighten until tension betweenseats is relieved.

5. Lift the entire yoke/bonnet assembly out ofthe valve body.

6. Remove the old gasket thoroughly clean andinspect the body-bonnet gasket surface andreplace with new gasket.

7. Following match marks, lower the entirebonnet-yoke assembly until the disc entersthe seats

8. Remove the disc clamp and completely lowerthe bonnet-yoke assembly.

9. Apply recommended lubricant to body-bon-net studs (15) and nut flats (16) tighten body/bonnet nuts in strict accordance withSection 4.5.2 and 4.5.3 and Table 4.5B.

10. For disc type II Fig. 8.3C the valve should bein a normally closed position.

11. Follow steps 2 and 3 above.



04

15B

11

12

03

26A

25 29

17A

02

18

15

19

01

09

07

10

45

46

43

Figure 8.2D Disassembly for gasket replacement

PARTS DESCRIPTION01 - Body02 - Bonnet03 - Yoke04 - Stem07 - Disc09 - Seat10 - Wedge guide11 - Packing flange12 - Gland bushing15 - Stud15B - Stud17A - HSH cap screw18 - Backseat19 - Gasket25 - Torque arm26A - Key29 - Bearing43 - Disc carrier45 - Retaining plate46 - Spring

50

12. Push the entire bonnet-yoke assembly towardseither left or right hand side. This will causethe stem to slide off the disc carrier T-HeadFig 8.3C. At this point follow steps 5 & 6above

NOTE: the disc will remain in the valve bodywhile the bonnet assembly is being lifted.

13. Follow match marks and carefully lower thebonnet-yoke assembly until the stem T-headlines up with disc carrier T-head Fig. 8.3C.Engage the stem T-head with disc carrier.Complete lowering the bonnet-yoke assemblyand follow step 9 above.

14. For disc type V Fig. 8.3E follow steps 10, 11above.

15. Turn the entire bonnet-yoke assembly 900

either way and lift out of the valve body.

NOTE: the disc will remain in the valve bodywhile the bonnet assembly is being lifted.

16. Replace with new gasket carefully lower thebonnet-yoke assembly and line up the stem T-head in parallel with the retainer plate (45)and disc carrier (43) connection Fig. 8.3E

17. Lower some more until the stem T-head entersinto the retainer plate and disc carrier T-headconnection. Turn back the bonnet-yokeassembly 900 this will engage stem/disc carrierT-head and the match marks should line up atthis point, Fig. 8.3E.

18. Complete lowering the bonnet-yoke assemblyand follow step (9) above.

8.3 TOTAL DISASSEMBLY OF PARALLEL SLIDE VALVES

8.3.1 General

Follow warning instructions in Section III beforebeginning disassembly. If valve is equipped witha gear or motor actuator, see Appendix for disassembly of actuators. As a general disassembly progresses, place matching marks on parts so that the same orientation of parts canbe maintained at reassembly.

8.3.2 Disassembly of Body/Bonnet and Disc/Stem

Refer to Fig. 8.1A. The disassembly instructionsthat are described below cover two of Velan’sbasic Parallel Slide Valve designs.


14. Before removing the discs from the stem, notethe orientation of the discs with respect to thetorque arm keyway in the stem. Each disc hasan identification mark on it which correspondsto an equivalent mark on a seat in the body.These seats and discs must be mated whenreassembling.

15. For removal of the stem and discs, use a parallel slide disc clamp. Fig. 8.3A shows thegeneral principle of the clamp.


Figure 8.3A Parallel slide disc clamp

PARTS DESCRIPTION1 - Arm2 - Adjusted screw3 - Cross member4 - Pivot pin

16. Lift stem and disc approximately three quarterway and with the use of disc clamp squeezethe two gate halves until they no longer touchthe body seats. Lift the stem/disc out of thevalve body and match mark, if not alreadydone so.

NOTE: In absence of disc clamp, standard “C”clamp can be used.

51


17. Velan has five parallel slide disc designs.

a) Disc Type I and IV (Fig. 8.3B):On Type I, the discs and springs will comeapart as soon as they are pulled out of thevalve body. To keep them from separatinga “C” clamp should be used duringremoval.

On Type IV, to disassemble disc from thestem, remove stem-disc assembly from thebody. Remove disc retaining rings oneither side. Carefully remove center piece,spring and identify each for valve involved.

b) Disc Type II (Fig. 8.3C):Disassemble discs from stem and disengage the stem (4) from the disc carrier(43) by pushing stem T-head out of T-slot inthe disc carrier. Remove the disc retainer(45) and the disc will spring apart. Carefullystore the springs (46). These should beidentified for the valve size involved. Thevalve is now ready for inspection andrepairs of seat, disc, stem, etc.

c) Disc Type III (Fig. 8.3D):To disassemble disc from the stem. Thelock brackets (31) must be opened by pry-ing the tabs upwards. The discs (7) can beremoved for repair or replacement, ifrequired, by removing the bolt (56a) andthe nut (16f), carefully remove the springs(46) and center piece (109). These shouldbe stored and identified for the valve sizeinvolved.

Figure 8.3B Parallel slide discs Type I – no retaining ring and Type IV uses part 45 retaining ring

04 - Stem07 - Disc45 - Retaining ring46 - Spring109- Center piece

Figure 8.3C Parallel slide disc Type II

04 - Stem07 - Disc43 - Disc carrier45 - Retaining plate46 - Spring

Figure 8.3D Parallel slide disc Type III

04 - Stem07 - Disc16F - Hex head nut31 - Lock bracket46 - Spring56A - Hex head bolt109 - Center piece

PARTS DESCRIPTION

PARTS DESCRIPTION

PARTS DESCRIPTION

04

07

07

46

43

45

52


d) Disc Type V (Fig. 8.3E):In this arrangement the stem (04) whenturned 90 degrees will disengage from disccarrier (43) and retainer plate (45). Oncethe stem is lifted the retainer plate connect-ing the disc and disc carrier can then beremoved

.

18. The valve is now ready for inspection andrepairs of seat, disc, stem, etc.

CAUTION: Use the disc clamp Fig. 8.3Abefore removing the retainer plate. Thisis to prevent discs from suddenly spreading out.

PARTS DESCRIPTION04 - Stem07 - Disc43 - Disc carrier45 - Retaining plate46 - Spring

Figure 8.3E Parallel slide disc Type V

8.3.3 Disassembly of Top Works (Fig. 8.3F)

Follow the warning instructions in Section IIIbefore beginning top works disassembly.

1. If line pressure is maintained in the valve,backseat the valve in fully open positionbefore starting any disassembly.

2. Remove small set screw (35A) in handwheelnut (30), then unscrew handwheel nut.

3. Before removing stroke limiter (49), measurethe distance the stud extends out of top ofstroke limiter. This distance regulates theposition of the two discs.

4. Remove stroke limiter (49) at the top of thestem.


6. Remove yoke housing bolting (17D) andremove housing cover (28).


8. Unscrew stem nut (88) from the stem (04).

9. After the stem nut has been removed, removesecond set of bearings (29b).

10. Now valve and parts are ready for inspection,repairs and replacement of stem nut, bearing,etc.

For gapinformationSee step (2)

“disc type II”For applicable

disc gapallowance

Parts Assembled

Figure 8.3F Valve top works disassembly

04

35A

34

29A

26B

88

29B

17D

30

33

28

03


53


8.4 ASSEMBLY

8.4.1 Top Works Assembly1. Apply new grease to threaded portion of stem

(04) above top flange on yoke (03).


Note: Bottom race must fit loosely aroundstem nut and top race must be tight aroundyoke nut. See Fig. 8.4A.


35A

26B

88

34

29B

17D

30 33

28

29A

03

04

3. Apply new grease to internal thread in stemnut (88) and screw stem nut on stem (04).Mount first set of newly greased bearings (29A)on stem nut.

NOTE: Bottom race must fit tightly aroundstem nut and top race must be loose.

4. After the bearing and stem nut are in place,

mount housing cover (28) on top and boltdown with the housing cover bolting (17D).Bolting must be torqued down in accordancewith the values in Table 5.3A.

5. Insert handwheel key (26B) in stem nut keywayand mount handwheel (33).



8. Return the stroke limiter (49) to the top of thestem. See Fig. 8.2A or Fig. 8.2B.

IMPORTANT: The position of the stroke limitermust be the same as that noted during valvedisassembly. If the original position has notbeen noted, the following readjustment procedure should be used:

a) Open valve fully to its back seated positionand mark up with a pen or marker.

b) Verify applicable valve project drawing forvalve “lift” (stroke). Measure from marked upopen position and draw a line (mark up) indi-cating valve closed position.

c) Close the valve to its marked up closed position and readjust stroke limiter.

9. For Motor Actuated Valves: It is necessary toreadjust open/close limit switch. Open limitswitch should be adjusted as a rule of thumb 1/4”(6 mm) off back seat. Closed limit switch shouldbe adjusted at already established closed posi-tion.


8.4.2 Body/Bonnet and Discs/Stem Assembly

1. Disc Type I (Fig. 8.3B)Install the spring (46) and disc center piece (109)in their respective holes in the discs (7). Use a“C” clamp to keep the discs together. Slip T-head of stem (75) into disc T-slot and partiallylower into the body seats

NOTE: The discs should be oriented as notedduring disassembly (match marked position). At this point remove “C” clamp and completelylower discs into valve body seats (9).

2. Disc Type II (Fig. 8.3C)Install spring (46) into the respective holes in the discs (07). Install disc in the disc carrier (43).Using the disc retaining plate (45) lock discs inplace. Slide T-head of stem (04) into T-slot on top of disc carrier (43) and use a discclamp or “C” type clamp to compress the disc

CAUTION: To prevent close torque switchtrip out, stroke limiter must be backed off by1/8”-1/4” (3- 6 mm) and set screw secured.



54


halves together. Partially lower the stem anddiscs into the seats. Remove the disc clamp (or “C” clamp) and measure the gap betweendisc retaining plate (45) and discs (07). Forvalve sizes 2”-12”(50 - 300 mm), a satisfactorygap should be 0.015”-0.020” (0.4-0.5 mm) perside. For valves 14” (350 mm) and up, the gapshould be 0.020”-0.030” (0.5 mm-0.75 mm)per side.

NOTE: The discs should be oriented as notedduring disassembly (match marked position).The discs are now assembled with proper“float” allowance.

3. Disc Type III (Fig. 8.3D)Install the three springs (46) and the center piece (109) in their respective holes in thediscs (07). Slip T-head of stem (04) into the T-head of discs and lined up with bolt holes.

NOTE: The discs should be oriented as notedduring disassembly (match marked position).

Insert the hex HD bolt (56A) and lock bracket(31a). The two discs should be pressedtogether against the stem T-head with discclamp or “C” clamp. Partially lower the stemand discs into the seats. Remove the discclamp or “C” clamp. With the two disc halvesplaced firmly against the body seats. Insertthe second lock bracket (31b) and thread nut(16F) onto the bolt. Make sure to leave a gapof 0.030”-0.045” (0.7-1.1 mm) between the nutand disc. Secure with lock bracket.

4. Disc Type IV (Fig 8.3B)Install spring (46) in center piece (109). Installcenter piece between discs and squeeze eitherside of disc, until you can install disc retainingrings (45) into machined groove. Slip T-headof stem into T-head of disc assembly.Partially lower the stem and discs into theseats and remove the disc clamp or “C” clamp

5. Disc Type V (Fig. 8.3E)Install spring (46) into the respective holes inthe discs (07) Install disc in the disc carrier(43). Using the disc retainer plate (45). Lockdiscs in place and use a disc clamp or “C”type clamp to squeeze the disc halves togeth-er. Line up stem T-head (04) in parallel withretainer plate and disc carrier T-head connec-tion. Lower the stem into T-head connectionand turn 90° to engage. Partially lower thestem and discs into the valve body seats.Remove the disc clamp and

measure the gap between disc retainer plate(45) and disc (07)

NOTE: See step two “Disc Type II” for applicable disc gap allowance.

6. Place new gasket in recess on top mountingface of body. Follow cleanliness and lubrication instruction as described in Section 8.2, Gasket Replacement. Refer to Fig. 8.2C and lubricate all stem threads.

7. Follow match marked position. Line up thebonnet/yoke assembly with the body andlower into the body. It is extremely importantthat one prevents the gasket from becomingdamaged when aligning the heavy bonnetassembly onto the body.

NOTE: When lowering the yoke/bonnetassembly, place the junk ring (63) if soequiped with the knurled side downward intothe packing chamber. The lantern ring (14), ifso equiped gland bushing (12), packing flange(11), and Type I or II torque arm (25) must bein correct positions before stem enters topflange on yoke, torque arm Type III or IV maybe assembled afterwards.

8. Apply recommended lubricant to body/bonnetstuds (15) & nut flats and then installbody/bonnet nuts (16). Tighten body/bonnetnuts in strict accordance with Section 4.5.2,Torque Procedure, 4.5.3 & Table 4.5B

9. Now continue step-by-step reassembly procedures as described in Section 8.4.1, TopWorks Assembly.

10. Repack valve in accordance with Section 5.1.4(valves without leak-off connection) andSection 5.1.5 (valves with leak-off connection).

11. Mount packing flange nut (16B) and live-loading option (if so equipped) and torque down in accordance with Section 5.1.6,Packing Torques.

NOTE: If the valve is equipped with live-loading option, live-loading parts mustreturn in the same order as noted in disassembly.


IMPORTANT: Please note that the torque armassembly should not be allowed to comeloose during valve operations. This is crucialto maintain the alignment of the stem T-headin the disc-carrier.

55

SWING CHECK & TILTING DISC VALVES IX

9.1 CHECK VALVE ASSEMBLY DRAWING

54

48

56

31

52

61

51

1615

66

56

31

51

09

08

50

19

54

61A

16A

58

01

57A

View "A"

View "A"

welded seat

Flow

Figure 9.1A Swing check assembly

PARTS DESCRIPTION01 - Body08 - Disc09 - Seat15 - Stud16 - Nut16A - Disc nut19 - Gasket31 - Locking bracket48 - Bushing50 - Cover51 - Hanger52 - Hanger block54 - Hinge pin56 - Hex head bolt57A - Discnut Washer58 - Cotter pin61 - Dowel pin61A - Disc pin66 - Name plate

56

IX SWING CHECK & TILTING DISC VALVES

9.2. GASKET REPLACEMENT

Follow the warning instructions in Section IIIbefore beginning disassembly.


2. Once all the nuts are removed, the cover (50)and gasket can be lifted from the valve body.

3. Place the new gasket (19) in the recess on thetop mounting of the body.

4. Line up the cover with the body and loweronto the body. It is extremely important toprevent the gasket from becoming damagedwhen aligning the heavy cover to the body.

5. Apply the recommended lubricant to thebody/cover studs (15) and nut flats and thenscrew on the body/cover nuts (16). Tighten thebody/cover nuts in strict accordance withSection 4.5.2, Torque Procedure, Section 4.5.3Application of Torque & Table 4.5B

9.3 TOTAL DISASSEMBLY

Follow warning instructions in Section III beforebeginning disassembly. As a general disassemblyprogresses, place matching marks on parts so thatthe same orientation of parts can be maintained atreassembly.

9.3.1 Body/Bonnet Disassembly


2. Once all the nuts are removed, the cover (50)and gasket can be lifted from the valve body.

3. The valve is now ready for inspection. At thispoint of the disassembly procedure, inspectthe rotation of the disc on the hanger and thealignment between the disc and seat. Ensurethat the hanger has free movement and is notseized or cannot be restricted by any internalpart.

4. After inspecting all points mentioned above,remove all internal parts by unfolding the lockbracket or tab washer (31) around the hex HDbolt (56) in body.

5. After the hex HD bolts (56) have beenremoved, the internal assembly can be liftedfrom the body.

9.3.2 Disc Disassembly

9.3.2.1 Swing Check

1. Velan has four major styles of swing checks.

a) Style I, Fig. 9.3A & B.Hinge pin (54) can be pushed out of hanger(51) and hanger block (52).

Hanger will disengage from hanger bracketbushing. There are four bushings (48) inthis style - two bushings in the hanger andtwo in the bracket.

b) Style II, Fig. 9.3C & D. Push hinge pin (54) out of the hanger (51).Remove two washers (57) from the pin.Push bushing (55) out of hanger.

c) Style III, Fig. 9.3E & F.Hinge pin (54) can be pushed out of thehanger (51) and hanger ring (53). Hangerwill disengage from hanger ring. There arefour bushings (48) in this style - two bushings in the hangers and two in thehanger ring.

d) Style IV, Fig. 9.3G & H.Push hinge pin (54) out of hanger ring (53)and hanger (51). Push bushing (55) out ofhanger.

2. To remove disc (8) from hanger (51), removecotter pin (58) from disc nut (16a). Unscrewdisc nut and remove disc washer (57A) anddisc (8). Now all parts are ready for inspectionand repairs of disc, seat, bushing, etc.

57


Figure 9.3A Swing check Style I Figure 9.3C Swing check Style II

Figure 9.3B Swing check Style I - exploded Figure 9.3D Swing check Style II - exploded

PARTS DESCRIPTION8 - Disc16A - Disc nut31 - Lock bracket48 - Hanger bracket51 - Hanger54 - Hanger pin55 - Bushing56 - Hex. HD bolt57A - Disc washer58 - Cotter pin61 - Dowel pin

PARTS DESCRIPTION8 - Disc 57 - Spacer washer16A - Disc nut 57A - Disc washer51 - Hanger 58 - Cotter pin54 - Hanger pin 60 - Tab washer55 - Bushing56 - Hex. HD bolt

58


Figure 9.3G Swing check Style IV

Figure 9.3H Swing check Style IV-explodedFigure 9.3F Swing check Style III - exploded

PARTS DESCRIPTION8 - Disc16A - Disc nut/Washercomb51 - Hanger53 - Hanger ring54 - Hanger pin55 - Bushing56 - Hex. HD bolt57 - Spacer washer58 - Cotter pin60 - Tab washer61 - Dowel pin

Figure 9.3E Swing check Style III

PARTS DESCRIPTION8 - Disc16A - Disc nut51 - Hanger53 - Hanger ring54 - Hanger pin55 - Bushing56 - Hex. HD bolt57A - Disc washer58 - Cotter pin60 - Tab washer

59


9.4 DETAILED MAINTENANCE

9.4.1 Body /Bonnet (Gasket) Leakage

9.4.1.1 General

To maintain the tightness of a factory-tested boltedbonnet valve, it is essential to apply sufficient bolttension at all times by having the proper torque onthe nuts or cap screws. The original torque mightbe lost due to vibration, relaxation of materialcaused by frequent temperature and pressure fluctuations, or by creep in high temperature applications. Joint bolt tension should be checkedat approximately one-year intervals and if necessary retighten in accordance with Section 2.9,Recheck for Bolt Tightness.

9.4.1.2 Leakage of Body-Bonnet Joint

Tighten body/bonnet stud and nut to values shownin Table 4.5B + 10%. Wait three to five minutesbefore determining if the leakage has stopped.The parts could have become loose during transportation or storage.

If tightening does not stop the leakage, the spiralwound flexitalic gasket is probably damaged andthe valve must be opened for examination. Such a leak can be caused by any of the following:

1. Imperfect seal between body/bonnet and gasket An incomplete seal can be caused bycorrosion or dirt chips or other foreign matterpushed between the seating surfaces of the body or bonnet and the seating faces of the gasket. An imperfect seal between the gasket and the inside contact surface of the body/bonnet can be caused by an imperfect surface caused by metal failure,sometimes after valve installation and use,which can cause subsequent leakage.

NOTE: Reusing the spiral wound flexitalic gasket is not recommended.

Velan recommends that the flexitalic gasketnot be reused. Spare gaskets should be kepton hand before opening the valve. Figure 9.3J Disc pin-seat match marked

Figure 9.3I Exploded view of a tilting disc unit

PARTS DESCRIPTION8 - Disc9 - Seat54 - Disc pin55 - Bushing56 - Hex. head bolt60 - Lock washer

9.3.2.2 Tilting Disc

1. Before disassembling disc (8), Fig. 9.3I, matchmark adjustment pin with seat (9) Fig. 9.3J.Most pins have a vertical groove between6 and 12 o’clock and a1/8” hole at the end at12 o’clock, this indicates pin offsetposition Fig. 9.3J. After match marking offsetposition, remove hex bolt (56), one per side, asin Fig 9.3I

2. Using a screw driver or any suitable tool, pushout the disc pin (54) towards the body wall,one per side as in Fig. 9.3I

CAUTION: Before the last pin is pushedout, hold disc unit securely with one handor chain hoist and push out the pin (54)with the other hand. This will prevent thedisc from falling in and causing possibledamage.

3. After the pins have been pushed out, take thedisc unit out of the valve body and place it in asecure area, caution should be taken not todamage valve, disc seating surface.

NOTE: Disc bushings (55) are individually fittedand should be marked for left and right hand side

60


9.4.2 Seat Leakage - Swing Check

9.4.2.1 Swing Check Disc Repairs

1. Disassemble the valve as described inSection 9.3, and inspect the disc and seat forscratches, pitting marks or other damage.

2. If the seating face of the disc is scratched, itmust be lapped. Slight pitting, grooving, orindentations no deeper than 0.005” (0.1 mm)can be removed by lapping. If defects cannotbe corrected by lapping, the disc can beground and/or machined. Velan recommendsthat no more than 0.031” (0.80 mm) beremoved. After machining or grinding is completed, lap the disc.

3. For the lapping, a flat plate (preferably madeof cast iron) should be used. An abrasive lapping compound should be mixed togetherwith olive oil and evenly distributed over theplate as shown in Fig. 9.4A. Only light, evenpressure should be applied and the discshould be moved in a figure 8 motion on theplate. Lift the disc as often as possible to prevent accumulation of particles in one areaand to allow for proper distribution of the lapping compound. The lapping plate shouldbe turned slightly every few strokes to maintain a flat surface. The part should belapped until seating faces are smooth.

4. Thoroughly clean off the lapping compoundwith a suitable cleaning fluid such as acetoneor alcohol. Do not use solvents containingchloride or fluoride.

NOTE: Fitting Of New Disc

When damage to the disc seating face cannotbe removed by grinding or lapping, the discmust be replaced. All new discs coming fromthe factory are already ground and should belapped before installation. See installationprocedures in Section 9.5.1, Disc AssemblyFit-Up.

9.4.2.2 Seat Repairs

If repairs are required on the seat of a swing checkvalve, the procedure is the same as described inSection 5.2.3.3.1, Seat Repairs - Gate & ParallelSlide Valves. The only difference between theseseats is the angle of the seat face. They can berepaired with an automatic grinding or lappingmachine or by the manual method.

9.4.3 Seat Leakage - Tilting Disc

9.4.3.1 Tilting Disc Repairs - GeneralIf minor damage to disc seating surface is noted, it should be lapped out using a seat ring havingan angle of 22°. Place (smear) medium grit lap-ping compound on seat ring and disc surface androck seat ring in an up and down motion, withlight pressure applied against the disc.

If major repairs become necessary, the discshould be repaired by machining. No more than0.015” (0.4 mm) should be removed.

NOTE: Disc seating surface is of a SphericalRadius.

9.4.3.2 Tilting Disc Seat Repairs - General

If minor damage to seating surface is noted, itshould be lapped out by using original disc. Place(smear) medium grit lapping compound on seatand disc surface. Reinstall disc with bushings andpins and move disc back and forth (open/close)slightly while applying light pressure against seat.

If major seat damage is noted, it should berepaired according to Section 5.2.3.3.1, SeatRepairs - Gate & Parallel Slide Valve.

NOTE: Tilting disc seat angle is 22°. A coneshaped disc or ring for hand or machine lapping may have to be fabricated with sameseat angle.

Figure 9.4A Lapping of disc

Hanger arm

Disc washer

Stainless steelcotter pin

Disc nut

1/32 Gap

Disc

Gap

Shoulder

Figure 9.5B Disc assembly clearances

61


9.5 ASSEMBLY

9.5.1 Disc Assembly Fit-upThis procedure is to be used when replacement ofdisc assembly parts or rework is required. Use itafter you have made sure that the body and discseats are clean, smooth, flat and free of any seating surface damage.

9.5.1.1 Swing Check Disc Unit1. Preassemble disc unit (Fig. 9.5A), making sure

that there is sufficient clearance between discwasher and hanger arm, disc post and armbore (Fig. 9.5B). Also ensure that hanger pin

rotates freely around Stellite bushings. The bushings should fit comfortably intohanger arm and hanger block bushing recess.A minimum of .010” (0.25 mm) bushingengagement with recess is required (engagement of less than .010” (0.25 mm) is cause for rejection). To determine actualengagement, follow these steps:

a) Measure both hanger arm bushing recessesand record (Fig. 9.5C).

b) Insert a screwdriver between bushing andhanger arm recess, push everything to oneside, and measure the gap with a fillergauge. Subtract this gap from each of thehanger arm recesses to get actual engagement (Fig. 9.5C).

c) For hanger block, do the same, exceptinsert a wedge-type object such as a screwdriver between the bushing andhanger block recess, push outward andmeasure gap. To get actual engagement,subtract this gap from each of the hangerblock recesses measured (Fig. 9.5D).

Cotter pin

Disc nut

Pin

Hanger arm

Seat

Body

Hex. bolt Hanger pin

Disc

Disc nutwasher

Figure 9.5A One type of Velan disc unit

Figure 9.5C Hanger arm recess

Figure 9.5D Engagement in hanger block

62


NOTE: Some hanger arms may have ananti-rotation stopper. This stopper is usedwith old style cast disc which has two smallpyramid-shaped stoppers. If the disc you arereplacing has a single stopper pin Fig. 9.5A(new style), then the hanger arm anti-rotationstopper is not required. It must be ground offflush so that it does not interfere with disc freemovement Fig. 9.5E.

9.5.1.2 Tilting Disc Unit (Fig. 9.3I)1. Install left and right side bushing (55), install

disc pins (54), push all the way towards bodywall (see Fig. 9.3I).

2. Carefully lower disc unit, align with bushings(55) and push pins (54) inward. Insert hex bolt(56) and lock washer (60) but do not tighten.Match marked pin with match mark on seat(see Fig. 9.3J) and verify gap at 3 o’clock usingwire feeler gauge.

NOTE: Min. gap allowance is 0.010”(0.25 mm). For adjustment rotate the disc pin clockwiseor counterclockwise using an “L” key asshown in Fig. 9.5F.

NOTE: If new parts are used or if parts werenot match marked ensure that maximumoffset position, usually marked with a

1/8” (0.25mm) hole, is at approximately 12o’clock position. The largest gap measured at6 o’clock means maximum offset at 12 o’clock,this type of adjustment is preferred. No lessthan 0.010” gap is allowed at 3 o’clock posi-tion.

3. With the disc pins (54) in place and adjusted,tighten hex bolts (56), one per side. Torque tovalues shown in Table 4.5B and secure withlock washer (60).

9.5.2. Bearing Blue or Developer Test

9.5.2.1 Swing Check (Removal of disc is required)

To perform a bearing blue or developer test thedisc unit must be preassembled as described inSection 9.5.1, Disc Assembly Fit-Up. First, smearor spray a light coating of bearing blue or dyedeveloper over the disc seating circumference.With one hand, hold the disc at its post or disc nut area. With the other hand, hold the hangerblock in place. Lower the whole disc unit into thevalve body and place the hanger block so that itmatches the dowel pin location holes (only if original hanger block is used). If the hanger blockis new, dowel pins are not required. To align thedisc manually, lower the disc unit, release the discgently against the seat, insert the hanger blockbolts and tighten finger-tight. Back off bolts quarter turn, press disc lightly against seat andretighten bolts finger-tight. With light pressureagainst disc, rotate disc slightly back and forth.Take hold of disc post/disc nut area and pull awayfrom body seat. Undo hanger block bolts andremove disc unit from valve body.

Figure 9.5E Removal of hanger arm stopper

Figure 9.5F Resetting of adjustment pins (54)using an “L” key

63


Examine disc seating area for contact.

1. If there is seating contact throughout thewhole seating circumference (360°), the disc iswell aligned with sufficient disc freedom. Thisalso indicates that the seating surfaces arewell mated and free of any damage.

2. If there is contact at the three or nine o’clockposition, the disc does not have sufficient freedom of movement in the disc hanger armbore. The disc should be held, but not constrained, by the hanger arm. The discshould be free to find its own seat. This freedom comes from the clearance betweenthe disc post OD and the hanger arm bore ID,and the gap between the hanger arm and thedisc nut washer. Confirm that the clearancesare adequate (Fig. 9.5B).

3. If there is contact at the 12 o’clock position(see Fig. 9.5G), the disc needs to be lifted bymachining. Material must be removed fromthe top of the disc post and base of the post,as shown in Fig. 9.5H.

NOTE: This condition is rare for a valve withits original parts. It sometimes occurs whennew seating surfaces have been added, whena new disc has been installed, or if a hangerarm has been replaced or bent (if bent, thehanger arm should be replaced).

4. If there is contact at six o’clock (see Fig. 9.5I ),the disc is too high in the hanger arm, or theseats are too low. This sometimes happensafter extensive lapping. To correct the problem, the disc must be lowered. The top of the hanger arm should be machinedand a washer of equal thickness “C” must beadded to the base of the disc post, as shown inFig. 9.5J. This will lower or “drop” the disc.

Gap

HingepinHanger

Disc nut

Cotterpin

Disc

12 o'clockcontact

Body

Seat

Figure 9.5G 12 o’clock contact

Hingepin

Hanger

Disc nutCotterpin

Disc

Body

Gap

Seat

6 o'clockcontact

Figure 9.5I 6 o’clock contact

Both heights must be equal

"C"

"C"

Area to be machined

Disc

Figure 9.5H Material removal from disc post

“C” Area to be machined

“C”

Figure 9.5J Machining of hanger arm

Washer

64


9.5.2.2 Tilting DiscPrior to reassembly, apply slight coating of bearing blue on valve seat surface. Reassembleper Section 9.5.1.2 - steps 1 and 2, and press discagainst seat. Disassemble and verify for 100% contact.

9.5.3 Paper or Light Test

9.5.3.1 Swing Check (Removal of disc is not required)

Paper test:

With the disc unit assembled, clean, dry andinstalled in the valve, conduct a paper test (similarto the bearing blue and developer test). The papershould be 0.001” to 0.002” (0.025 to 0.050 mm)thick, 1” (25 mm) wide and about 8” (200 mm)long. Lift the disc off the seat enough to put thepaper between the two seats and gently lower thedisc. Pull the paper out with just enough force sothat the paper does not rip. Do this test around thedisc, taking special note at the top (12 o’clock) position, at the bottom (6 o’clock) position, and atboth sides (three and nine o’clock). Make a recordof where the paper holds and where the paper pullswithout ripping.

1. If paper pulls at 3 o’clock or 9 o’clock position,the disc cannot move enough in the dischanger arm bore. The disc should be free tofind its own seat. This freedom comes fromthe clearance between the disc post OD and the hanger arm ID, and the gap between thehanger arm and the disc nut washer. Confirmthat the clearances are adequate (Fig. 9.5B).

2. If the paper pulls at the 12 o’clock position(contact at 6 o’clock) (see Fig. 9.5I ), the disc istoo high in the hanger arm, or the seats are toolow. This sometimes happens after extensivelapping. To correct the problem, the disc mustbe lowered. The top of the hanger arm shouldbe machined and a washer of equal thickness“C” must be added to the base of the disc post,as shown in Fig. 9.5J. This will lower or “drop”the disc

3. If the paper pulls at the 6 o’clock position (contact at 12 o’clock) (see Fig. 9.5G), the discneeds to be lifted by machining. Materialmust be removed from the top of the disc postand base of the post, as shown in Fig. 9.5H.

NOTE: If paper cannot be used, the same testcan be done using shim stock material.

Light test:

Use a small flash light and position it on the upstream side with the light facing the disc. Observeany light indication when disc is closed. Recordthe position of light (gap) and then proceed withrepairs as for paper test.

9.5.3.2 Tilting Disc

Light test:

Prior to reassembly, insert a flash light, reassemble per Section 9.5.1.2 - steps 1 and 2, andcheck for light indication. If light is noted, rotateboth disc pins clockwise or counter-clockwise asnecessary until light indication disappears. Matchmark disc pins and disassemble. Remove flashlight and reassemble per Section 9.5.1.2 - steps 1through 4.

Alternate test:

Using feeler gauge 0.001”(0.025 mm) and feelergauge shim stock, check between the disc and seatall around 360° seating circumference. If feelergauge enters between seats, rotate both disc pinsclockwise or counter-clock as necessary until feeler gauge no longer penetrates between seats. The disc is now properly aligned with 360°circumferential contact

9.5.4 Internal and Mid-Section Assembly- Swing Check Valve

NOTE: If disc and/or disc nut are new, cotterpin hole may not have been pre-drilled. Inthis case drilling is to be done at site beforereassembly.

1. Mount disc (8) on hanger (51), place disc nutwasher (57A), tighten disc nut (16a) and lockin place with cotter pin (58). Check if disc canrotate freely on hanger.

NOTE: Disc nut and disc nut washer maybesupplied as combination (one piece)

2. Depending on the swing check style proceedas follows:

a) Style I (Figs. 9.3A & B)Place two bushings (55) in hanger and twoin hanger bracket (48). Insert hinge pin (54)into the hanger (51) and push pin throughthe hanger bracket into the opposite side ofthe hanger.

b) Style II (Figs. 9.3C & D)Push bushing (55) into hanger (51) andinsert hinge pin (54) into bushing. Placeone spacer washer (57) on each side ofhanger pin.

c) Style III (Figs. 9.3E & F)Place two bushings (55) in hanger and twobushings in hanger ring (53). Insert thehinge pin (54) into the hanger (51) and pushpin through the hanger ring to the oppositeside of the hanger.

d) Style IV (Figs. 9.3G & H)

Push the bushing (55) into the hanger (51)and insert the hinge pin (54) into the hangerring (53). Place and line up one spacerwasher (57) on each side. Push pin throughthe bushing to the opposite side of thehanger ring.

3. Place the entire assembly carefully back in thebody. For Style I (Fig. 9.3A and Fig. 9.3B) withoriginal hanger bracket and body seat.Ensure proper disc alignment by insertingdowel pins (61) in their respective holes inhanger bracket (48) and top of body seat,making sure that the hanger pin can movefreely in an axial direction.

NOTE: Alignment with dowel pins can onlybe achieved using original hanger bracket andbody seat. If the hanger bracket or body seatis being replaced DO NOT USE DOWEL PINS

65


FOR ALIGNMENT. Use following manualalignment method which is applicable to allswing check valves without dowel pins:Follow steps 1, 2 & 3 A, B, C or D. Insert lockbracket or tab washer (60) and hand tightenhex HD bolts (56) then back off half to oneturn, with one hand over center of disc, pressagainst the body seat and with the other hand,tighten down hex bolts. Complete tighteningin accordance with Section 5.3 Torque Values -Yoke / Bonnet Bolting, Table 5.3A TorqueValues for yoke / actuator / bonnet bolting andcontinue steps 4 & 5.

4. Insert lock bracket or tab washer (60) andtighten down with hex bolts (56) seeSection 5.3, Table 5.3A Torque Values for yoke / actuator / bonnet bolting. Lock thebolts by turning up the ears on the lock brackets.

5. After installation, check the rotation of the discon the hanger and the alignment between discand seat.

9.5.5 Body/Cover Assembly - Swing Check & Tilting Disc

1. Place the new spiral gasket (19) in the recesson the top mounting of the body.

2. Line up the cover with the body and loweronto the body. It is extremely important toprevent the gasket from becoming damagedwhen aligning the heavy cover to the body.

3. Apply the recommended lubricant to thebody/cover studs (15) and nut flats and thenscrew on the body/cover nuts (16). Tightenthe body/cover nuts in strict accordance with Section 4.5.2, Torque Procedure andSection 4.5.3 Table 4.5B

X APPENDIX

Figure 10.1A Manual gear actuator—Style 1

10.1 PROCEDURE FOR REMOVING MANUAL GEAR ACTUATOR

Velan valves can be equipped with a variety ofmanual gear actuators. Actuators of this typecome in two main styles: one for applicationswhere only rotary torque is required, and onefor applications requiring both rotary torque and linear thrust.

Generally, all pressure must be relieved from bothsides of the valve before removal of the manualgear actuator. Exceptions to this rule includevalves which have a self-contained unit.

IMPORTANT: Determine the actuator stylethat is mounted on the valve you are servicing.If it is not possible to determine thestyle of actuator, refer to the actuator manufacturer's maintenance and instructionmanual or contact your local Velan representative for more technical assistance.

10.1.1 Style I (Fig. 10.1A)

1. Valves with Style 1 manual gear actuators are equipped with a self-contained thrust unit.This actuator can be removed under linepressure.

2. Remove housing actuator bolting (17B).

3. Using a hoist, raise the actuator (32) above thestem (4) and stem nut (88).

4. To repair the actuator, refer to the manufacturer's instruction manual. If there isfurther work to do on this valve, refer to theappropriate section of this manual.

5. The disassembly of the self-contained thrustunit follows the same procedure as describedin Disassembly Valve Top Works.

PARTS DESCRIPTION03 - Yoke04 - Stem17A - Yoke/housing cap screw17B - Yoke/adaptor cap screw28 - Yoke/housing cover29A - Bearing32 - Gear actuator34 - Grease fitting88 - Stem nut113 - Stem nut gear driver

66

APPENDIX X

10.1.2 Style 2 (Fig.10.1B)

1. Valves with a Style 2 manual gear actuator are equipped with a self-contained thrust unitwhich will be removed with the actuator.Therefore the actuator cannot be removedunder line pressure. The pressure must berelieved.

NOTE: In case the valve can be fully opened,then the actuator can be removed under linepressure. Follow steps 3,4,5 and 6.


3. Make sure that the packing flange nuts are tight.

4. Remove the yoke-actuator bolting (17B).

5. Turn the actuator handwheel clockwise. Thiswill cause the actuator (32) to rise and unthreadfrom the valve stem. As this takes place, theweight of the actuator should be supported by a hoist to prevent damage to thestem thread or any internal part of the valve.

NOTE: Applications where both rotary torque and linear thrust are required.

Figure 10.1B Manual gear actuator—Style 2

PARTS DESCRIPTION03 - Yoke

04 - Stem

17B - Yoke/actuator cap screw

32 - Gear actuator

ASSEMBLY EXPLODED VIEW

6. To repair the actuator, refer to the manufacturer's instruction manual. If there isfurther work to be done on the valve, refer tothe appropriate section of this manual.

IMPORTANT: Velan does not recommend interchanging of actuator parts as this maycause parts to be misfitted that could result inactuator damage making the valve inoperable. If parts must be interchanged contact VelanCustomer Service Department for instruction.

CAUTION: When reinstalling actuator, the valve should be in a slightly off-seated position (main seat or backseat) for centering purposes.

67

68

X APPENDIX

IMPORTANT: For torque seated valves, thetorque switch of the motor-actuated valve isset during factory assembly to close the valveagainst the specified differential pressure andrequires the same special attention for resetting.

WARNING: Should it become necessary tochange the torque switch setting for any reason, contact your Velan Customer ServiceManager to obtain a correct new setting fromthe factory.

10.2 PROCEDURE FOR REMOVINGMOTOR ACTUATOR

Velan valves can be equipped with a variety ofelectrical motor actuators. Motor actuators aremounted through two different methods. Someunits are attached directly to the yoke (Fig. 10.2A),and some are attached to an adaptor plate andthen to the valve yoke (Fig. 10.2B). Both methodshave the same removal procedure.

Figure10.2A Motor actuator - Direct attament

Figure 10.2B Motor actuator - Adaptor plate attachment (Assembly)

Refer to Fig. 10.2C and Fig. 10.2D

NOTE: If the valve is in full open position, themotor actuator and bevelgear can be removedunder line pressure, otherwise.

CAUTION:

1. If the valve packing material is changedfor any reason, the torque switch settingmay have to be changed in this casecontact Velan customer serviceDepartment

2. Upon reassembly of a valve equippedwith an electro-mechanical actuator, theopen and close limit switches must bereset. Please refer to the maintenanceand instruction manual provided by theactuator manufacturer for appropriateinstructions.

IMPORTANT: Velan recommends toreset open limit switch as a rule ofthumb 1/4” (6 mm) off back seated position. For torque seated valves onlythe close limit switch should be adjustedat approximately 95% of closed valvetravel, this is to allow sufficient torqueswitch by-pass during unseating.

3. When checking for proper rotation ofthe electrical actuator, make sure thatthe valve is in mid-stroke position. If the three-phase wiring connection isincorrect, the valve will close when theopen button is pressed and the closetorque switch will not function, whichcould damage the valve. If the valvedoes not travel in the correct direction,then simply interchange any two of thethree power connections.

4. When checking for full stroke of thevalve without pressure in the line, theclosing torque switch should be set toits minimum value which will close thevalve until all testing is finished. Thetorque switch should then be reset to its recommended value.

69

APPENDIX X

1. All pressure must be relieved from both sidesof the valve before removing the motor actuator and bevelgear.


3. Disconnect the electrical wiring from theactuator.

4. Tighten the packing flange nuts.

5. Remove all actuator bolting (17C) from theunderside of the yoke flange.

NOTE: If removing the motor actuator withbevelgear Fig. 10.2D, remove hex bolts (17)push out the motor actuator (32) frombevelgear keyed stem (33). If removing bevelgear, remove cap screws (17C), rotatebevelgear clockwise this will cause the bevelgear to unthread from the stem.

6. All electrical actuators have an automatichand-wheel declutching arrangement. Inmost cases, move the lever from the motor operation position to the hand operation position (manual mode).

NOTE: Do not try to force declutch lever intoan operation position.

Figure 10.2C Motor actuator - Adaptor plateattachment (Exploded view)

PARTS DESCRIPTION03 - Yoke04 - Stem15 - Adaptor/actuator

stud16 - Adaptor/actuator

nut17C -Yoke/adaptor

cap screw32 - Motor actuator37 - Adaptor plate

3433

17

32

17C

50

04

03

Figure 10.2D Bevelgear actuator(Exploded view)

7. Turn the actuator handwheel clockwise toclose the valve. This will cause the actuator torise and unthread itself from the valve stem.As this takes place, the weight of the actuatorshould be supported by a hoist to preventdamage to the stem or to the internal parts ofthe valve.

8. If further disassembly of the actuator isrequired, refer to the maintenance manualprovided by the actuator manufacturer.

9. If there is further work to be performed on thevalve, refer to the proper valve disassemblyand maintenance section in this manual.

CAUTION: When reinstalling actuator, thevalve should be in the slightly off-seatedposition (main seat or backseat) forcentering purposes.

PARTS DESCRIPTION03 - Yoke 32 - Motor actuator04 - Stem 33 - Bevelgear actuator17 - Bevelgear/actuator hexbolt 50 - Stem protector17C -Yoke/bevelgear cap screw

Figure 10.3A Examples of coupling

Figure 10.3B Removal of actuators

PARTS DESCRIPTION3 - Yoke4 - Stem17B - Yoke/actuator

cap screw32 - Actuator35 - Coupling

set screw97 - Coupling

PARTS DESCRIPTION4 - Stem4 - Actuator stem16 - Jam nut97 - Coupling

70

X APPENDIX

10.3 PROCEDURE FOR MOTOR HYDRAULIC OR PNEUMATIC ACTUATORS (Fig. 10.3A)

The following instructions will give you a generalguide for removal and reinstallation of a hydraulicor pneumatic actuator. All hydraulic or pneumaticactuators have a connection between the valvestem and the stem of the actuator. All these connections are formed by some type of coupling.Fig. 10.3A illustrates some examples of couplingused on Velan valves. As a rule, examine this connection first to understand how the couplingworks.

Removal of Actuators (Fig. 10.3B )

1. All pressure must be relieved from both sidesof the valve before removal of actuator.

2. All air pressure must be relieved from actuatorbefore disassembly.

3. Remove yoke-actuator bolting (17B).NOTE: In case of fail close actuator type (airfail spring to close). Before air is relievedreplace two capscrews (17B) one opposite theother with longer (twice the length) studs orthreaded rod, relieve air and gradually releasespring tension by backing off stud nuts.

4. Loosen coupling (97).

NOTE: On some actuators, it is necessary torotate the actuator stem to remove thisconnection.

5. When the stem threads are disengaged, liftthe actuator (32) clear of the yoke and place itdown on a clean area. If further disassembly on the actuator is required, refer to the manufacturer's maintenance and instructionmanual.

PRECAUTION: Examine coupling (97)for set screw (35) or any locking devicebefore loosening it.

6. If there is further work to be performed on thevalve, refer to the proper valve disassemblysection in this manual.

CAUTION: When reinstalling actuator,the valve should be slightly off seatedposition (main seat or backseat) for centering purposes.

10.4 SPARE PARTSAll parts on any valve can be ordered, but Velandoes not recommend changing all parts in the field(e.g. integral seat, integral backseat, wedge guides,etc.).

Changing these parts may require special fitting. Inthese cases, it is best to get in touch with your localVelan representative who will help you determinethe way to restore your valve with a minimum oftime and expense.

When ordering spare parts, correctly determinewhich parts are required. After this is done, presentVelan with the following information, preferably:

1. Velan order number2. Velan item number (if more than one item)3. Velan figure number and drawing number

(usually found on the valve name plate)

OR (in absence of the above)1. Customer order number2. Customer item number3. Valve size, type, pressure class and drawing no.

71

TERMS AND CONDITIONS OF SALE

CONTRACT: Orders are subject to acceptance bythe Velan Companies hereinafter referred to as theseller. No terms or conditions of Purchaser's ordercontrary to the Seller's terms and condition shallbe binding upon the Seller unless specificallyagreed to by the Seller in writing.

MINIMUM ORDER CHARGE: $500.00 net.PRICES: All quoted prices are subject to change bythe seller without prior notice and, unless other-wise stipulated by Seller, are understood to beF.O.B. Seller's plant, with delivery to carrier consti-tuting delivery to purchaser. Right to possession ofthe material to secure the payment of the purchaseprice shall remain in Seller until all paymentstherefore shall have been fully made. For the pro-tection of the Purchaser and the Seller, verbal cus-tomer orders must be confirmed by a formal writ-ten purchase order. If a written purchase order isnot received within ten days or a verbal order,product descriptions, quantities, specifications,etc., as set forth in Seller's acknowledgement andinvoice shall be conclusive and binding on bothparties. Any order that is shipped before receipt ofconfirmation which might have been entered incor-rectly and would require remedial action would befor the Purchaser's account.

TAXES: All prices are exclusive of taxes. Sales,use and other taxes, by whomsoever levied, are tobe paid by the Purchaser, and unless invoiced, areto be paid by the Purchaser directly to the appro-priate governmental agency.

DELIVERY: Delivery or shipment specified isSeller's best estimate and Seller shall not be liablefor delay in deliveries resulting from any causewhatsoever. Failure to ship on or near the estimat-ed date shall not entitle Purchaser to cancel hisorder without charge.

RETURN OF MATERIALS: Materials may bereturned only with prior written agreement ofSeller.

CANCELLATION: Cancellation of orders may bemade only with the Seller's written consent andPurchaser shall be subject to cancellation charges.PRODUCT WARRANTY: Seller warrants the equip-ment of its own manufacture to be free of defectsin material and workmanship, under normal useand proper operation for a period of one year fromthe date of shipment from Seller's plant. Seller'sobligation under warranty shall be strictly limited,at Seller's option, to: (i) furnishing replacementparts for or repairing without charge to Purchaser,F.O.B. Seller's plant or (ii) issuing written autho-rization for Purchaser or others to replace or repairwithout charge to Purchaser, at costs comparableto Seller's normal manufacturing costs those parts

proven defective, or (iii) in discharge of Seller'smaximum liability herewith, refunding all moniespaid by Purchaser to Seller for the Product and, atdiscretion of Seller, having the product removedand returned to Seller at Purchaser's expense. Alltransportation charges relative to corrective work,defective parts or replacement parts shall be borneby Purchaser. Purchaser shall give Seller immedi-ate notice upon discovery of any defect. Theundertaking of repairs or replacements byPurchaser or its agents without Seller's writtenconsent shall relieve seller of all responsibilityherewith.

Finished materials and accessories purchasedfrom other manufacturers are warranted only tothe extent of the manufacturer's warranty toSeller.

Any alteration in material or design of Seller's prod-uct or component parts thereof by Purchaser or oth-ers without written authorization by Seller voids allobligations of Seller regarding the product and anyassociated warranty herein stated or implied.

Seller's sole liability shall be exclusively as setforth herein, and Seller shall not be liable for anyincidental or consequential damages due to itsbreach of any warranty herein contained, or other-wise. Without limitation to the foregoing, in noevent shall Seller be liable for the loss of use ofthe product or of any other product, process,plant, equipment, or facilities of the Purchaser orend-user whether partially or wholly due todefects in material and /or workmanship and /ordesign of Seller's product, and in no event shallSeller be liable for removal of appurtenances orincidentals such as connections, pipe work andsimilar items of obstruction or for any costbrought about by the necessity of removing theproduct from its point of installation.

Seller makes no warranty of any kind whatsoever,expressed or implied, other then is specifically stat-ed herein; and there are no warranties of mer-chantability and/or fitness for a particular purposewhich exceed the obligations and warranties specifi-cally stated herein.

Parts furnished without charge as replacementsfor original parts under warranty are warranted forthat period of time during which the original partswarranty is effective.

ALL SHIPMENTS WILL BE F.O.B. PLANT LOCATION.SHIPMENTS WILL BE MADE VIA MOST ECONOMI-CAL CARRIERS UNLESS OTHERWISE REQUEST-ED.TERMS: NET 30 DAYS FROM DATE OF INVOICE:11⁄2% PER MONTH OF ALL OVERDUE ACCOUNTS,ALL TAXES EXTRA. PRICES SUBJECT TO CHANGEWITHOUT NOTICE.

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