Vibration: 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 overal
Trang 1Centrifugal Pump Vibrations:
The Causes
by Steven J Hrivnak, P.E.
Associate Mechanical Engineer
Tennessee Eastman Eastman Chemical Company
EASTMAN
Trang 2FAULTS REPORTED OVER 3 YEARS
Trang 3Vibration: 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
Trang 4Three Basic Causes of Pump
Vibrations:
• Mechanically Induced
• System Induced
• Operation Induced
Trang 8System Induced
• Partially/Plugged Strainer
• Clogged Impeller or Suction Line
• Installation
Trang 9PIPING?
Trang 14and Baseplates
Trang 15The mass ratio must be 3:1 to
minimize vibration
Trang 25Cavitation and Flow
Trang 27High Temp Rise
Low Flow Cavitation
Low Bearing and Seal Life
Reduced Impeller Life
Trang 33You can’t run a pump with suction
and discharge valves closed!
Trang 35Minimum Flow
1750 rpm 15-20% BEP Flow
3500 rpm 30-50% BEP Flow
Trang 36Maximum Flow
110-115% BEP Flow
Trang 41Speed
Trang 44Suction Pipe Immersion
Trang 47Avoid Max Size Impellers
Conclusions
Trang 48Avoid Max Size Impellers
Keep speed to 1750 max
Conclusions
Trang 49Avoid Max Size Impellers
Keep speed to 1750 max
Keep flow in design range
Conclusions
Trang 50Avoid Max Size Impellers
Keep speed to 1750 max
Keep flow in design range
Grout your baseplates
Conclusions
Trang 51Avoid Max Size Impellers
Keep speed to 1750 max
Keep flow in design range
Grout your baseplates
Use proper piping
Conclusions
Trang 52Avoid Max Size Impellers
Keep speed to 1750 max
Keep flow in design range
Use proper piping
Avoid hydraulically induced problems like
cavitation, and suction and discharge re-circulation, submergence.
Conclusions