Cavitation Failure Analysis

 

Cavitation is caused by the presence of gas bubbles under high pressure being suddenly subjected to a low pressure.  This causes the bubbles to burst (implode) and release energy to the metal surface, which causes the fracture of small, minute pieces of metal from the base casting.

Possible Causes

Seal Water/Liquid Compressant

  • Incorrect seal water (liquid compressant) rates
  • Operation of liquid compressant above its vapor pressure
  • Liquid compressant saturated with minute gas bubbles under pressure

Blocked Discharges

  • Discharge port, pump outlet or drain blocked
Improper Clearances
  • Clearance wide on pumps operating at high vacuum levels

Improper Working Pressure

  • Working beyond maximum operating pressure (vacuum or compressor)

Possible solutions

Seal Water/Liquid Compressant

  • Ensure proper seal water/compressant rate
  • Change vacuum or sealant water temperature
  • Change liquid compressant
  • Remove bubbles from liquid compressant



Blocked Discharges

  • Unblock all ports, outlets and drains

Improper Clearances

  • Ensure proper clearance is maintained


Improper Working Pressure

  • Lower operating pressure

 

A Nash Field Service Technician can help you diagnose a cavitation issue, and can alert you about poor conditions before problems begin.  For more on these options, use the links below.