vibration analysis and acceptance standard

CORPORATE STANDARD Advisory Predictive

Maintenance Vibration Analysis and Acceptance Standard Revision #

3.1 Issue Date 11.11.2004

Document # of 21 6.24.2011 Reviewed By: Richard Tyler Approved by: PdM Steering Group

1.0 PURPOSE

The purpose of this standard is to describe the methods for the development, implementation, and management of the PacifiCorp Generation routine vibration analysis program. This standard provides engineering performance guidelines for new/rebuilt equipment acceptance and continued operation parameters of rotating equipment use by the PacifiCorp Generation fleet. The vibration limits establish a common goal of acceptability and the methods required for data acquisition excluding on-line data acquisition systems, turbines and generators.

This standard does not limit the analyst with required instrumentation or methods. Rather, it defines the final orientation, outcome, and documentation required for equipment history.

2.0 SAFETY

Safety is the number one priority. Be alert and move slowly, deliberately, and cautiously when working around rotating equipment. Common sense is the greatest safety tool that can be used. At a minimum, follow guidelines set forth in the PacifiCorp Accident Prevention Manuals and manufacturers written recommendations.

Ensure that cables, probes, clothing, and hands are kept clear of moving parts. When testing is being performed under fluorescent lighting or using a strobe light, exercise caution, because rotating machinery sometimes appears to be stopped or rotating slowly when actually rotating at normal speeds.

Placing probes on some machines could be hazardous when the machine is running. In such cases, the probes should be placed with long lead wires while the machine is not running.

3.0 BACKGROUND

Vibration analysis is a nondestructive, diagnostic activity that encompasses the acquisition and interpretation of the dynamic response of operating rotating machinery in the form of vibration data samples to determine machine condition.

The rewards of accurate and precise vibration analysis will:

a. Reduce PacifiCorp Generation's operating costs by establishing acceptable vibration levels for plant rotating equipment.

b. Improve the life and performance of the Generation fleet's rotating equipment.

c. Provide a uniform procedure for evaluating the vibration characteristics of the Generation fleet's rotating equipment.

d. Provides incipient fault and failure detection. e. Reduces maintenance costs due to minimizing equipment damage.



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f. Provides advanced maintenance planning opportunities.

4.0 SCOPE 4.1. This standard establishes acceptable limits for vibration levels and is to be

used to establish a new database, machine specifications, machine acceptance and continuous machine operations.

4.2. This standard establishes measurement procedures--including standardized measurement axis directions and locations, calibration and performance requirements of instrumentation, and procedures for reporting vibration data for machine acceptance.

5.0 STANDARD

5.1. Instrumentation Requirements for Portable Vibration Analyzers

5.1.1. FFT Analyzer shall meet or exceed the minimum specifications outlined below. 5.1.1.1.The FFT analyzer shall be capable of acquiring 6,400 Lines

of Resolution. 5.1.1.2.The FFT analyzer shall be capable of acquiring 20,000 Hz. 5.1.1.3.The FFT analyzer shall be capable of acquiring a Dynamic

Range 72 dB. 5.1.1.4.The FFT analyzer shall be capable of applying a Hanning

window for analyzing vibration and Uniform window for impact testing.

5.1.1.5.The FFT analyzer shall be capable of linear non-overlap averaging.

5.1.1.6.The FFT analyzer shall have anti-aliasing filters.

5.1.2. Portable Vibration Analyzer Measurement System Accuracy - The measurement system (FFT analyzer, cables, transducer and mounting) used to take vibration measurements shall have a measurement system Amplitude accuracy over the linear frequency range of ±5% for Displacement, Velocity and Acceleration.

5.1.3. Amplitude Uncertainty: Uniform or Rectangular (impact testing) 56.5%; Hanning (fault analysis) 18.8%; Flat Top (condition evaluation) 1.0%.

5.1.4. Shaft Relative Proximity Probe Glitch: All glitch (electrical or mechanical) shall be 0.5 mils peak-peak or less as measured in-situ at 100 RPMs.

5.1.5. Measurement System Calibration - Vibration equipment used to take vibration measurements must be calibrated by a qualified instrumentation laboratory within a one (1) year prior. Calibration



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shall be traceable to the National Institute of Standards and Technology (NIST).



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5.1.6. Machine Information for Developing Routes – Detailed machine design and historical information is required to establish an advanced vibration analysis program. This information should be gathered during machine design, installation and repairs (see attachments).

5.1.7. Vibration Measurement Locations, Directions and Conventions 5.1.7.1.Identification of Sampling Locations Vibration Data

Collection Number each bearing in sequence from the non-driven (NDE) end bearing of the driver (typically a motor or turbine), through the power train (in the direction of power flow), through to the non-driven (NDE) end bearing of the ultimately driven component following table below. Understanding the power flow sequencing of the machine train is vital to the diagnostic evaluation of vibration spectral data. For vertical pumps horizontal reading should be indentified 90° perpendicular to the plane of discharge flow.

5.1.7.2.Physical Marking of Measurement Points Each point where vibration data will be periodically collected shall have 1-1/8 in diameter by 1/8 in thick (minimum) cold-rolled ferrous stainless steel disk attached as a data collection target. Each target shall be stamped with the appropriate identifier (example: Motor Outboard Horizontal = MOH).

5.1.7.3.Displacement Probes When X & Y displacement probes are used, use the appropriate letter to designate the sensor position, i.e., A, B, C, D, E, etc., for bearings 1, 2, 3, 5, etc. The letters for horizontal and vertical (H & V) can be substituted for X & Y if desired (optional). However, when substituting H &

Equipment ID-ABC Identifier "A"

Identifier "B"

Identifier "C" M Motor I Inboard H Horizontal T Turbine O Outboard V Vertical E Engine A Axial A Axial P Pump X Radial-X (Horizontal) F Fan Y Radial-Y (Vertical) C Compressor P PeakVue G Gearbox



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V for X & Y, one must adopt a convention for determining which probes correspond to horizontal and vertical as X/Y probes often do not correspond to true horizontal and vertical. In general, a horizontal (X axis) displacement probe mounted in the top half of a bearing should be located on the right side of the vertical centerline (clockwise from vertical) when viewed from the driver end regardless of direction of shaft rotation.

5.1.8. Vibration Measurement Units 5.1.8.1.Displacement - Mils, Peak-Peak 5.1.8.2.Velocity – in/sec, Peak 5.1.8.3.Acceleration - g's, Peak

5.1.9. Frequency Maximum (Fmax), Low Frequency Cutoffs

Application Low Frequency Cutoffs

Frequency Maximum

Lines of Resolution Averages Window Type

Sleeve Bearings for machines w/o vanes 120 CPM 20xRPM 1600 8 Hanning Sleeve Bearing machine with Vanes (or Blades) 120 CPM

20xRPM or 1.2BPF 1600 8 Hanning

Gear Box, Unknown # of Teeth 120 CPM 200xGMF 3200 8 Hanning Gear Box, known # of Teeth 120 CPM 3.2xRPM 3200 8 Hanning Electric Motor, Rotor Pass 120 CPM 360,000 CPM 3200 8 Hanning Electric Motor 120 CPM 12,000 CPM 1600 8 Hanning Tapered or Spherical Roller Bearings 120 CPM 50xRPM 1600 8 Hanning Roller Bearings machines > 1700 RPM 120 CPM 40xRPM 1600 8 Hanning Roller Bearings machines 1400 - 1700 RPM 120 CPM 50xRPM 1600 8 Hanning Roller Bearings machines 1100 - 1400 RPM 120 CPM 60xRPM 1600 8 Hanning Roller Bearings machines 800 - 1100 RPM 120 CPM 80xRPM 1600 8 Hanning Roller Bearings machines 600 - 800 RPM 120 CPM 100xRPM 1600 8 Hanning



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5.1.10. Vibration Analysis and Acceptance Limits Criteria for Overall Vibration Condition Rating (Peak Overall, Velocity, In/Sec) 1 Assuming machine speed = 600 - 60,000 RPM 2 Assuming measurements by accelerometer or velocity pickup securely mounted as close as possible to bearing housing. 3 Assuming machine is not mounted on vibration isolators (For isolated machinery - Set Alarms 30%-50% higher). 4 Set motor Alarms the same as that for the particular machine type unless otherwise noted. 5 Set Alarms on individual external gearbox positions about 25% higher than that for a particular machine type.

Machine Type Good Fair Alarm 1

(Warning) Alarm 2 (Fault)

Cooling Tower Drives a) Long, hollow drive shaft 0 - 0.4 0.4 - 0.6 0.6 0.9 b) Close coupled belt drive 0 - 0.3 0.3 - 0.4 0.4 0.7 c) Close coupled direct drive 0 - 0.2 0.2 - 0.3 0.3 0.5 Compressors a) Reciprocating 0 - 0.3 0.3 - 0.5 0.5 0.8 b) Rotary Screw 0 - 0.3 0.3 - 0.5 0.5 0.7 c) Centrifugal - with or W/O external gearbox 0 - 0.2 0.2 - 0.3 0.3 0.5 d) Centrifugal - Integrated gear (axial meas.) 0 - 0.2 0.2 - 0.3 0.3 0.5 e) Centrifugal - Integrated gear (radial meas.) 0 - 0.2 0.2 - 0.3 0.3 0.4 Fans/Blowers a) Lobe-type rotary 0 - 0.3 0.3 - 0.5 0.5 0.7 b) Belt driven blower 0 - 0.3 0.3 - 0.5 0.5 0.7 c) General direct drive fans (with coupling) 0 - 0.3 0.3 - 0.4 0.4 0.6 d) Primary air fans 0 - 0.3 0.3 - 0.4 0.4 0.6 e) Forced draft fans 0 - 0.2 0.2 - 0.3 0.3 0.5 f) Induced draft fans 0 - 0.2 0.2 - 0.3 0.3 0.4 g) Shaft mounted integral fans 0 - 0.2 0.2 - 0.3 0.3 0.4 h) Vane-Axial fans 0 - 0.2 0.2 - 0.3 0.3 0.4 Turbine/Generators a) 3600 RPM Turbine/Generators Refer to OEM Specifications b) 1800 RPM Turbine/Generators Refer to OEM Specifications Centrifugal Vertical Pumps a) Vertical pumps (12'-20' high) 0 - 0.3 0.3 - 0.5 0.5 0.8 b) Vertical pumps (8'-12' high) 0 - 0.3 0.3 - 0.4 0.4 0.6 c) Vertical pumps (5'-8' high) 0 - 0.2 0.2 - 0.4 0.4 0.5 d) Vertical pumps (0'-5' high) 0 - 0.2 0.2 - 0.3 0.3 0.5 Centrifugal Horizontal Pumps a) General purpose, direct coupled 0 - 0.2 0.2 - 0.3 0.3 0.5 b) Boiler feed pumps 0 - 0.2 0.2 - 0.3 0.3 0.5 c) Hydraulic Pumps 0 - 0.1 0.1 - 0.2 0.2 0.3

* Note: the "Alarm1" and "Alarm2" overall levels given above apply only to in-service machinery which has been operating for some time after initial installation and/or overhaul. See section 5.7.2 for Acceptance Criteria for New and Rebuilt Machinery.



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5.1.11. Vibration Monitoring Spectral Band Alarm Limits

SPECTRAL BAND ALARM LIMITS a) General Sleeve Bearing Machines

(without vanes) Band Frequency Range Alarm Setting

1 [0.2 → 0.8] x RPM 20% Overall Alarm 2 [0.8 → 1.8] x RPM 90% Overall Alarm 3 [1.8 → 2.8] x RPM 40% Overall Alarm 4 [2.8 → 3.8] x RPM 30% Overall Alarm 5 [3.8 → 10.2] x RPM 25% Overall Alarm 6 [10.2 → 20] x RPM 20% Overall Alarm

b) Gearbox (known number of teeth)

Band Frequency Range Alarm Setting 1 [0.25 → 0.75] x GMF 25% Overall Alarm 2 [0.75 → 1.25] x GMF 70% Overall Alarm 3 [1.25 → 1.75] x GMF 25% Overall Alarm 4 [1.75 → 2.25] x GMF 50% Overall Alarm 5 [2.25 → 2.75] x GMF 25% Overall Alarm 6 [2.75 → 3.25] x GMF 40% Overall Alarm

c) Gearbox (unknown number of teeth)

Band Frequency Range Alarm Setting 1 [20 → 50] x RPM 60% Overall Alarm 2 [50 → 80] x RPM 60% Overall Alarm 3 [80 → 110] x RPM 50% Overall Alarm 4 [110 → 140] x RPM 50% Overall Alarm 5 [140 → 170] x RPM 40% Overall Alarm 6 [170 → 200] x RPM 40% Overall Alarm

d) Electric Motor Rotor Bar (measured at motor outboard bearing horizontal)

Band Frequency Range Alarm Setting 1 [30k → 85k] x CPM 0.06 in/sec 2 [85k → 140k] x CPM 0.06 in/sec 3 [104k → 195k] x CPM 0.05 in/sec 4 [195k → 250k] x CPM 0.045 in/sec 5 [205k → 305k] x CPM 0.04 in/sec 6 [305k → 360k] x CPM 0.035 in/sec

e) Electric Motor (measured at motor inboard bearing horizontal)

Band Frequency Range Alarm (600-2k) RPM

Alarm (2k-4k) RPM

1 [240 → 2k] x CPM 90% OA Alarm 30% OA Alarm 2 [2k → 4k] x CPM 40% OA Alarm 90% OA Alarm 3 [4k → 6k] x CPM 40% OA Alarm 40% OA Alarm 4 [6k → 8k] x CPM 35% OA Alarm 35% OA Alarm 5 [8k → 10k] x CPM 30% OA Alarm 30% OA Alarm 6 [10k → 12k] x CPM 25% OA Alarm 25% OA Alarm

f) Tapered or Spherical Roller Element Bearing Machines (without vanes)



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Band Frequency Range Alarm Setting 1 [0.4 → 1.2] x RPM 90% Overall Alarm 2 [1.2 → 2.2] x RPM 40% Overall Alarm 3 [2.2 → 3.2] x RPM 30% Overall Alarm 4 [3.2 → 12.2] x RPM 25% Overall Alarm 5 [12.2 → 20] x RPM 20% Overall Alarm 6 [20 → 50] x RPM 15% Overall Alarm

g) General Roller Element Bearing Machines (without vanes)

Band Frequency Range Alarm Setting 1 [0.4 → 1.2] x RPM 90% Overall Alarm 2 [1.2 → 2.2] x RPM 40% Overall Alarm 3 [2.2 → 3.2] x RPM 30% Overall Alarm 4 [3.2 → 12.2] x RPM 25% Overall Alarm 5 [12.2 → 20] x RPM 20% Overall Alarm 6 [20 → Fmax] x RPM 15% Overall Alarm

h) Centrifugal Machines (known number of vanes or blades & roller bearings)

Band Frequency Range Alarm Settings 1 [0.4 → 1.2] x RPM 90% Overall Alarm 2 [1.2 → 2.2] x RPM 40% Overall Alarm 3 [2.2 → (BPF-1.2)] x RPM 35% Overall Alarm 4 [(BPF-1.2) → (BPF+1.2)] x RPM 60% Overall Alarm 5 [(BPF+1.2) → 20] x RPM 35% Overall Alarm 6 [20 → Fmax] x RPM 20% Overall Alarm

i) Centrifugal Machines (unknown number of vanes or blades & roller bearings)

Band Frequency Range Alarm Settings 1 [0.4 → 1.2] x RPM 90% Overall Alarm 2 [1.2 → 2.2] x RPM 40% Overall Alarm 3 [2.2 → 3.2] x RPM 30% Overall Alarm 4 [3.2 → 6.8] x RPM 60% Overall Alarm 5 [6.8 → 20] x RPM 35% Overall Alarm 6 [20 → Fmax] x RPM 20% Overall Alarm

j) Centrifugal Machines (known number of vanes or blades & sleeve bearings)

Band Frequency Range Alarm Settings 1 [0.2 → 0.8] x RPM 20% Overall Alarm 2 [0.8 → 1.8] x RPM 90% Overall Alarm 3 [1.8 → 3.8] x RPM 40% Overall Alarm 4 [3.8 → (BPF-1.2)] x RPM 30% Overall Alarm 5 [(BPF-1.2) → (BPF+1.2)] x RPM 70% Overall Alarm 6 [(BPF+1.2) → 20] x RPM 35% Overall Alarm

k) Centrifugal Machines (unknown number of vanes or blades & sleeve bearings)

Band Frequency Range Alarm Settings 1 [0.2 → 0.8] x RPM 20% Overall Alarm 2 [0.8 → 1.8] x RPM 90% Overall Alarm 3 [1.8 → 3.8] x RPM 40% Overall Alarm 4 [3.8 → 7.8] x RPM 70% Overall Alarm 5 [7.8 → 9.8] x RPM 25% Overall Alarm



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6 [9.8 → 20] x RPM 35% Overall Alarm

5.2. Routine Data Collection – Requirements for regular data collection of vibration data. 5.2.1. Collecting Vibration Samples of Equipment Operating at a

Limited Capacity. Process variable must be collected to reflect any changes in vibration analysis spectrum.

5.2.2. Collecting Vibration Samples for Comparative Data to On-Line Systems. Online vibration data collection shall be collected as route data if the online system is not capable of condition assessment.

5.3. Continuous Diagnostic Monitoring

5.3.1. All turbo machinery, boiler feed pump, forced draft and induced draft shall include Bently Nevada System 1 diagnostic platform.

5.3.2. Continuous diagnostic monitoring of critical equipment shall include the ability to perform advanced vibration analysis functions included, but not limited to: Orbit, Bode, Time Wave, Spectrum, Polar, Centerline, Waterfall Plots, and Transient Events storage.

5.3.3. Measurement Point Setup – Refer to condition monitoring OEM recommendations, administer modify as necessary.

5.3.4. Data Storage – Startups and Shutdowns, monthly auto archiving are required for all critical equipment monitored.

5.4. Data Reduction and Analysis

5.4.1. Initial baselines shall be established when the machine component is first monitored after acceptance criteria has been met and running under normal operational condition. Baseline data shall form the reference base for vibration trending.

5.4.2. New baselines are to be established following any maintenance activities which would improve established baseline data.

5.4.3. Collected vibration data shall be compared to component baselines during every monitoring period to identify adverse trends or abnormal equipment conditions.

5.4.4. Collected vibration data shall be reviewed for the identification of any alert, warning, or alarm conditions. Any readings which are indicative of degrading equipment condition shall be reported and a plan developed to resolve the problem.

5.5. Reporting and Notification 5.5.1. Develop, maintain, and publish a "vibration route problem report"

to process owners, planners, and plant management.



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5.5.2. Report equipment problem to person(s) responsible for maintenance of equipment in failure mode and ensure notification is written.

5.5.3. Report equipment condition on new or rebuilt equipment to person responsible for maintenance on that piece of equipment and maintain history.

5.5.4. Record in “History” section of vibration software relevant data of failure, repairs required, complete repairs, rebuilds, etc.

5.5.5. Maintain and report required vibration analysis performance indicators.

5.6. Equipment Analysis, Acceptance and Verification 5.6.1. Machinery Vibration System Verification – Prior to release for

service, vibration systems shall be verified for proper installation and accuracy.

SECTION 5.7.2 5.6.2. AC MOTORS ANALYSIS AND ACCEPTANCE

5.6.2.1.Alternating current motors will be tested at rated voltage and frequency, and no load. Single speed alternating current motors will be tested at synchronous (running) speed. A multi-speed alternating current motor will be tested at all its rated synchronous (running) speeds. Direct current motors will be tested at their highest rated speed. Series and universal motors will be tested at operating speed.

5.6.2.2.Method of Motor Isolation for Measuring Vibration Place the motor on an elastic mounting so proportioned that the up and down natural frequency shall be at least as low as 25 percent of the test speed of the motor. To accomplish this it is required that the elastic mounting be deflected downwards at least by the amounts shown in the following table due to the weight of the motor. When a flexible pad is used the compression shall in no case be more than 50 percent of the original thickness of the flexible pad; otherwise the supports may be too stiff.

MOTOR SYNCHRONOUS SPEED(RPM)

ISOLATION PAD COMPRESSION(INCHES)

600 2-1/4 900 1

1200 9/16 1800 1/4 3600 1/16 7200 1/64

Note: The required deflection is inversely proportional to the speed squared.



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Table 1

Completely assembled motors shall have a percentage separation between the rotor shaft first actual critical speed and the rated motor speed as specified:

ROTOR DESIGN

FIRST ACTUAL CRITICAL SPEED LOCATION

Rigid Shaft At least 25% Above Rated Motor Speed

Flexible Shaft Maximum of 85% of Motor Speed Table2

Table 3

MAXIMUM ALLOWABLE VIBRATION LEVELS FOR ELECTRIC MOTORS

BAND FREQUENCY RANGE

VELOCITY LINE AMPLITUDE

BAND LIMITS (INCH/SEC

PEAK)

ACCELERATION BAND LIMITED

OVERALL AMPLITUDE LIMITS

(g’s PEAK) 1 0.3 x RPM

0.8 x RPM0.04 0.5

2 0.8 x RPM1.2 x RPM

0.075 0.5


0.04 0.5


0.03 0.5

5 8.5 x RPM60,000 CPM

0.03 0.5

6 60,000 CPM120,000 CPM

0.03 0.5



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RUNNING SPEED ORDERS

.10

.09

. 08

.07

.06

.05

.04

.03

.02

.01

BAND 1

BAND 2

BAND 3

BAND 4

BAND 5

BAND 6

1 2 3 4 5 6 7 8 9 10 11

.04

.075

.04

.03 .03 .03

Velocity (in/sec)

ELECTRIC MOTOR AMPLITUDE BAND LIMITS

.

Fmin = 0.3 CPM Fmax = 120k CPM

Figure 1 Figure 2

ELECTRIC MOTOR OVERALL

AMPLITUDE ACCEPTANCE LIMITS

1.0

0.9

0.7

0.6

0.5 0.4 0.3

0.2 0.1

BAND 1

0.5g ELECTRIC MOTOR OVERALL

Acceleration (g’s)

FREQUENCY (CPM) Fmin = 0.3 CPM Fmax = 120k CPM

0.8



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SECTION 5.7.3 5.6.3. FANS ANALYSIS and ACCEPTANCE

5.6.3.1.Fans are defined as: All non-positive displacement air handling units including Induced Draft (ID) Fans, Forced Draft (FD) Fans, Overhung Fans, Centerhung Fans, Centrifugal, Vaneaxial, Tubeaxial, Blowers, etc.

5.6.3.2.Shaft Tolerance Fan shaft diameter shall meet bearing manufacturer specifications for shaft tolerances.

5.6.3.3.Resonance Natural frequencies of the completely assembled fan unit shall not be excited at the operating speed. (Running speed should be at least 25% removed from a natural frequency of the system.)

5.6.3.4.Limits New and Rebuilt/Repaired Fans shall conform to the vibration limits specified in Table 4 when operating at specified system CFM and Fan Static Pressure. The frequency range for fan certification shall be from Fmin = 0.3 X Running Speed of Fan to 60,000 cpm for velocity and to 120,000 cpm for acceleration.

For fan speeds up to 3600 RPM, the maximum velocity amplitude (inch/sec-Peak) of vibration at bearing locations in any direction shall not exceed the Line Amplitude Band Limit values specified in Table 4 and graphed in Figure 3. For fan speeds up to 3600 RPM, the Band-Limited Overall vibration level of acceleration (g's Peak) at bearing locations in any direction shall not exceed the Band-Limited Overall Amplitude Acceptance Limit values specified in Table 4 and graphed in Figure 4.

Acceptance limits for fans running over 3600 RPM shall be specified by the purchaser.



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MAXIMUM ALLOWABLE VIBRATION LEVELS FOR FANS

BAND FREQUENCY RANGE VELOCITY LINE AMPLITUDE BAND LIMITS (INCH/SEC PEAK)

1 0.3 x RPMmin 0.8 x RPM fan

0.04 DIRECT COUPLED 0.075 BELT DRIVE

2 0.8 x RPM fan 1.2 x RPM fan/motor

0.075

3 1.2 x RPM fan/motor 3.5 x RPM fan/motor

0.04

4 3.5 x RPM fan/motor to Fmax = 60,000 CPM

0.03

ACCELERATION BAND LIMITED OVERALL AMPLITUDE LIMITS

(g’s PEAK) 1 0.3 x RPMmin

to Fmax = 120,000 CPM 0.5

RPMmin = Lowest system speed (e.g. Belt speed if Belt Driven, Fan speed if direct drive coupled RPM fan/motor = Fan or motor speed whichever is greater (IN/SEC)

Table 4

BAND 2

V E L O C I T Y

.10

.09

.08

.07

.06

.05

.04

.03

.02

.01 (in/sec)

RUNNING SPEED ORDERS Fmin=0.3 RPM 1 2 3 4 10 Fmax =60K

.075 .075

.04. 04 .03

BAND 1 BAND 3 BAND 4

BAND ACCEPTANCE LIMITS for FANS

Figure 3



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Figure 4

5.6.3.5.Other Requirements

Variable speed or adjustable sheaves shall not be used in the final installation. Drive sheave and driven sheave should differ in size by 20 % or more to avoid "beat" vibration

A C C E L E R A T ION

1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1

FREQUENCY - CPM

Fmax = 120K

0.5g (Peak)

BAND 1

BAND-LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS



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SECTION 5.7.4 5.6.4. PUMPS ANALYSIS and ACCEPTANCE

5.6.4.1.Pumps shall be defined in two (2) categories: • Positive Displacement --including, but not limited

to Piston, Gear, and Vane. • Centrifugal

5.6.4.2.Operating Conditions • Non-cavitating non-separating condition. • No piping strain. • Shaft coupling aligned. • Straight suction pipe to pump. (Reference Hydraulic

Institute Standard) • Certification shall be performed while pumps are

operating within design specifications. 5.6.4.3.Limits For Positive Displacement & Centrifugal Pumps

For purposes of Line Amplitude evaluations a "PUMPING FREQUENCY" (PF) band will be established. The PF Band will be centered on the Pumping Frequency (Number of pumping elements X Pump RPM). The band will extend + 2 lines of resolution on either side of the line of resolution containing the Pumping Frequency. (i.e. Bandwidth = 5 lines of resolution)

Excluding the lines of resolution contained in the Pumping Frequency (PF) Band, the Velocity Amplitude (Inch/sec-Peak) of any line of resolution, measured at bearing locations in any direction shall not exceed the Line-Amplitude Band Limit values specified in Table 5 and graphed in Figure 5.

The Velocity Band-Limited Overall Amplitude (Inch/sec - Peak) at bearing locations in any direction shall not exceed the Pumping Frequency Band Limited Overall Amplitude Acceptance Limit value specified in Table 5 and graphed in Figure 5.

The Acceleration Band-Limited Overall Amplitude (g's Peak) at bearing locations in any direction shall not exceed the Band-Limited Overall Amplitude Acceptance Limit values specified in Table 5 and graphed in Figure 6.



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MAXIMUM ALLOWABLE VIBRATION LEVELS FOR POSITIVE DISPLACEMENT AND CENTRIFUGAL PUMPS

LINE-AMPLITUDE BAND LIMITS

BAND

FREQUENCY RANGE (CPM)

VELOCITY (INCH/SEC - PEAK)

1 0.3 x RPM 0.8 x RPM

0.04

2 0.8 x RPM 1.2 x RPM

0.075

3 1.2 x RPM 3.5 x RPM

0.04

4 3.5 x RPM 120,000 CPM

0.03

BAND-LIMITED OVERALL AMPLITUDE LIMITS

BAND FREQUENCY RANGE (CPM)

ACCELERATION (g’s PEAK)

1 0.3 x RPM - 300K CPM 1.5g - POSITIVE DISPLACEMENT 1.0g - NON-POSITIVE DISPLACEMENT

PUMPING FREQ.

BAND (PF) FREQUENCY RANGE (CPM)


BAND 5 5 Lines of resolution

centered on PF. 0.075 PISTON

0.05 VANE Table 5

BAND 2

V ELO C IT Y

.10

.09

.08

.07

.06

.05

.04

.03

.02

.01 (in/sec)


1 2 3 4 5 6 7 8 9 10 11 Fmax = 120K Fmin=0.3

.075 PISTON.075

.04.04.03


POSITIVE DISPLACEMENT & CENTRIFUGAL PUMPSBAND AMPLITUDE ACCEPTANCE LIMITS

BAND 5

.05 VANE

NOTE: Band 5 is a floating band width of the pumping frequency ± 2 lines of resolution acceptance limits for band 5 are line amplitude vibration levels



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Figure 5

Figure 6

5.6.4.4.Vertical Mounted Pumps

Vertically mounted pump systems with a "Vertical Mount Height" greater than 5 feet will have an allowable increase in Velocity Amplitude Acceptance Limits in Bands 1, 2, and 3 of 5% per foot of "Vertical Mount Height" greater than 5 feet. (e.g. A 7 foot Vertical Mount Height would yield a 10% increase [(7 ft - 5 ft) x 5%/ft] in the Table 9.4A Velocity Amplitude Acceptance Limits specified for Bands 1, 2, and 3. Therefore the limit for Band 1 would be [0.4 Inch/sec + (0.4 Inch/sec x 0.1)] = 0.44 Inch/sec-Peak. Vertical Mount Height is defined as the furthest measurable distance from the machine mounting to the end of the driver or the end of the pump, which ever is greater.

A C C E L E R A T ION

2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2

FREQUENCY - CPM

Fmax = 300K

1.0g CENTRIFUGAL PUMPS

BAND 1

POSITIVE DISPLACEMENT & CENTRIFUGAL PUMPSBAND-LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS

(g’s)

1.5g POSITIVE DISPLACEMENT PUMPS



3.1 Issue Date 11.11.2004


SECTION 5.7.5 5.6.5. GEARBOXES ANALYSIS and ACCEPTANCE

Gearboxes shall not exceed the Vibration Limits specified table 6 and in Figures 7 and 8.

MAXIMUM ALLOWABLE VIBRATION LEVELS FOR GEARBOXES

LINE-AMPLITUDE BAND LIMITS BAND



1 0.3 x RPM 0.8 x RPM

0.04

2 0.8 x RPM 1.2 x RPM

0.075

3 1.2 x RPM 3.5 x RPM

0.04

4 3.5 x RPM 120,000 CPM

0.03




1 0.3 x RPM – 3.5 x GMF or 600K CPM

1.0

Table 6

BAND 2

V E L O C I T Y

.10

.09

.08

.07

.06

.05

.04

.03

.02

.01 (in/sec)

1 2 3 4 5 6 7 8 9 10 11 Fmax = 120K Fmin=0.3

.075

.04.04

BAND 1 BAND 3

GEAR BOXBAND AMPLITUDE ACCEPTANCE LIMITS

.03

BAND 4


Figure 7



3.1 Issue Date 11.11.2004


A C C E L E R A T I O N

1.00.90.80.70.60.50.40.30.20.1

FREQUENCY - CPM Fmax = 3.5 X GMF or 600K (Which ever is greater)

1.0g (Peak)

BAND 1

GEAR BOXBAND LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS

(g’s)

Figure 8



3.1 Issue Date 11.11.2004


SECTION 5.7.6 5.6.6. COMPRESSOR ANALYSIS and ACCEPTANCE

5.6.6.1. Centrifugal Compressors

Centrifugal compressors shall not exceed the Vibration Limits specified in Table 7 and Figures 8 and 9.

5.6.6.2. Positive Displacement

Positive displacement compressors shall not exceed the Vibration Limits specified in Table 7 and Figures 8 and 9.

MAXIMUM ALLOWABLE VIBRATION LEVELS FOR POSITIVE

DISPLACEMENT AND CENTRIFUGAL COMPRESSORS

LINE-AMPLITUDE BAND LIMITS BAND



1 0.3 x RPM 0.8 x RPM

0.04

2 0.8 x RPM 1.2 x RPM

0.075

3 1.2 x RPM 3.5 x RPM

0.04

4 3.5 x RPM 120,000 CPM

0.03




1 0.3 x RPM - 300K CPM 1.5g - POSITIVE DISPLACEMENT 1.0g - NON-POSITIVE DISPLACEMENT

Table 7



3.1 Issue Date 11.11.2004


Figure 8

A C C E L E R A T I ON

2.0 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2

FREQUENCY - CPM

Fmax = 300K

1.0g CENTRIFUGAL COMPRESSORS

BAND 1

POSITIVE DISPLACEMENT & CENTRIFUGAL COMPRESSORSBAND-LIMITED OVERALL AMPLITUDE ACCEPTANCE LIMITS

(g’s)

1.5g POSITIVE DISPLACEMENT COMPRESSORS

BAND 2

V ELO C IT Y

.10

.09

.08

.07

.06

.05

.04

.03

.02

.01 (in/sec)


1 2 3 4 5 6 7 8 9 10 11 Fmax = 120K Fmin=0.3

.075

.04 .04 .03


POSITIVE DISPLACEMENT & CENTRIFUGAL COMPRESSORSBAND AMPLITUDE ACCEPTANCE LIMITS



3.1 Issue Date 11.11.2004


Figure 9

6.0 REFERENCES 6.1. “PacifiCorp Employees”. A special thanks to the dedicated plant

employees for their insight and input. 6.2. “General Motors Corporation”. Specification No. V1.0a, GM_1761:

Vibration Standard for the Purchase of New and Rebuilt Machinery and Equipment..

6.3. "EPRI". Project 2817-01, TR103374: Predictive Maintenance Guidelines. 6.4. "Technical Associates of Charlotte". Level II Vibration Analysis

Handbook.

vibration analysis and acceptance standard

Documents

vibration limits

plant rotating equipment

vibration characteristics

precise vibration analysis

background vibration

machine acceptance

acceptance standard

acceptable vibration