Centrifugal Pump Vibrations: The Causes by Steven J. Hrivnak, P.E. - - PowerPoint PPT Presentation

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Centrifugal Pump Vibrations: The Causes by Steven J. Hrivnak, P.E. - - PowerPoint PPT Presentation

Dec 26, 2022 156 likes •720 views

Centrifugal Pump Vibrations: The Causes by Steven J. Hrivnak, P.E. Associate Mechanical Engineer Tennessee Eastman Eastman Chemical Company EASTMAN FAULTS REPORTED OVER 3 YEARS Vibration: a measure of reliability! a measure of reliability!

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Centrifugal Pump Vibrations: The Causes

by Steven J. Hrivnak, P.E.

Associate Mechanical Engineer Tennessee Eastman Eastman Chemical Company

EASTMAN

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SLIDE 2

FAULTS REPORTED OVER 3 YEARS

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SLIDE 3

Vibration: Vibration: a measure of reliability! a measure of reliability!

Poorly installed and operated pumps average .178 in/sec overall vibration and have 6 months life. Properly installed pumps average .071 in/sec overall vibration and have 60 months life.

EASTMAN

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SLIDE 4

Three Basic Causes of Pump Three Basic Causes of Pump Vibrations: Vibrations:

  • Mechanically Induced

Mechanically Induced

  • System Induced

System Induced

  • Operation Induced

Operation Induced

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Mechanically Induced Mechanically Induced

  • Bad bearings

Bad bearings

  • Bent Shaft

Bent Shaft

  • Unbalanced Rotor

Unbalanced Rotor

  • Check Valve Installed Backwards

Check Valve Installed Backwards

  • Mis

Mis-Alignment

  • Alignment
  • Looseness

Looseness

  • Soft Foot

Soft Foot

  • Maximum Size Impeller

Maximum Size Impeller

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SLIDE 6
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SLIDE 7
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System Induced System Induced

  • Partially/Plugged Strainer

Partially/Plugged Strainer

  • Clogged Impeller or Suction Line

Clogged Impeller or Suction Line

  • Installation

Installation

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PIPING?

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Foundations Foundations and and Baseplates Baseplates

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The mass ratio must be 3:1 to The mass ratio must be 3:1 to minimize vibration minimize vibration

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Operationally Induced Operationally Induced

  • Cavitation

Cavitation

  • Flow

Flow

  • Speed

Speed

  • Insufficient Immersion of Suction Pipe or

Insufficient Immersion of Suction Pipe or Bell Bell

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Cavitation and Flow Cavitation and Flow

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SLIDE 26
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Operating Off The B.E.P.

Flow Head

High Temp. Rise Low Flow Cavitation Low Bearing and Seal Life Reduced Impeller Life Suction Recirculation Discharge Recirculation B.E.P. Low Bearing and Seal Life Cavation

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SLIDE 28
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SLIDE 33

You can’t run a pump with suction You can’t run a pump with suction and discharge valves closed! and discharge valves closed!

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SLIDE 34
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Minimum Flow Minimum Flow

1750 rpm 15-20% BEP Flow 1750 rpm 15-20% BEP Flow 3500 rpm 30-50% BEP Flow 3500 rpm 30-50% BEP Flow

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SLIDE 36

Maximum Flow Maximum Flow

110-115% BEP Flow 110-115% BEP Flow

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SLIDE 37
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SLIDE 38
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SLIDE 39
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Speed Speed

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SLIDE 42
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SLIDE 43
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Suction Pipe Immersion Suction Pipe Immersion

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SLIDE 47

EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers

Conclusions Conclusions

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EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers Keep speed to 1750 max Keep speed to 1750 max

Conclusions Conclusions

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SLIDE 49

EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers Keep speed to 1750 max Keep speed to 1750 max Keep flow in design range Keep flow in design range

Conclusions Conclusions

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SLIDE 50

EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers Keep speed to 1750 max Keep speed to 1750 max Keep flow in design range Keep flow in design range Grout your baseplates Grout your baseplates

Conclusions Conclusions

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SLIDE 51

EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers Keep speed to 1750 max Keep speed to 1750 max Keep flow in design range Keep flow in design range Grout your baseplates Grout your baseplates Use proper piping Use proper piping

Conclusions Conclusions

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SLIDE 52

EASTMAN

Avoid Max Size Impellers Avoid Max Size Impellers Keep speed to 1750 max Keep speed to 1750 max Keep flow in design range Keep flow in design range Grout your Grout your baseplates baseplates Use proper piping Use proper piping Avoid hydraulically induced problems like Avoid hydraulically induced problems like cavitation, and suction and discharge re-circulation, cavitation, and suction and discharge re-circulation, submergence. submergence.

Conclusions Conclusions

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SLIDE 53
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SLIDE 54

5 PUMPS - 6 YR. MTBF 8 PUMPS - 5 YR. MTBF 15 PUMPS - 4 YR. MTBF 5 PUMPS - 6 YR. MTBF 8 PUMPS - 5 YR. MTBF 15 PUMPS - 4 YR. MTBF