22-12-2012, 05:10 PM
PUMP FAILURE MODES
1PUMP FAILURE.pdf (Size: 2.28 MB / Downloads: 27)
CAVITATION
Symptoms
1. The pump sounds like it is pumping rocks!
2. High Vacuum reading on suction line
3. Low discharge pressure/High flow
4. Power draw not as per manufacturers curve
Causes
1. Clogged suction pipe
2. Suction line too long
3. Suction line diameter too small
4. Suction lift too high
5. Valve on Suction Line only partially open
6. Discharge pressure too low
Suction Cavitation occurs when the pump suction is under a
low pressure/high vacuum condition where the liquid turns
into a vapour at the eye of the pump impeller.
This vapour is carried over to the discharge side of the pump
where it no longer sees low pressure and is compressed back
into a liquid by the discharge pressure. This imploding action
occurs violently and attacks the face of the impeller.
An impeller that has been operating under a suction cavitation
condition has large chunks of material removed from its face
causing premature failure of the pump