Page 241 - Intro Predictive Maintenance

Table 10–8 Common Failure Modes of Centrifugal Compressors

THE PROBLEM

Excessive Vibration Compressor Surges Loss of Discharge Pressure Low Lube Oil Pressure Excessive Bearing Oil Drain Temp. Units Do Not Stay in Alignment Persistent Unloading Water in Lube Oil Motor Trips

THE CAUSES
Bearing Lube Oil Orifice Missing or Plugged
Bent Rotor (Caused by Uneven Heating and Cooling)
Build-up of Deposits on Diffuser
Build-up of Deposits on Rotor
Change in System Resistance
Clogged Oil Strainer/Filter
Compressor Not Up to Speed
Condensate in Oil Reservoir
Damaged Rotor
Dry Gear Coupling
Excessive Bearing Clearance
Excessive Inlet Temperature
Failure of Both Main and Auxiliary Oil Pumps
Faulty Temperature Gauge or Switch
Improperly Assembled Parts
Incorrect Pressure Control Valve Setting
Insufficient Flow
Leak In Discharge Piping
Leak In Lube Oil Cooler Tubes or Tube Sheet
Leak in Oil Pump Suction Piping
Liquid “Slugging”
Loose or Broken Bolting
Loose Rotor Parts
Oil Leakage
Oil Pump Suction Plugged
Oil Reservoir Low Level
Operating at Low Speed w/o Auxiliary Oil Pump
Operating in Critical Speed Range
Operating in Surge Region
Piping Strain
Poor Oil Condition
Relief Valve Improperly Set or Stuck Open
Rotor Imbalance
Rough Rotor Shaft Journal Surface
Shaft Misalignment
Sympathetic Vibration
Vibration
Warped Foundation or Baseplate
Wiped or Damaged Bearings
Worn or Damaged Coupling
Source: Integrated Systems, Inc.