Q & A – What is the difference between NPSHa and NPSHr ?

2020-07-24T12:20:26+01:00 July 24th, 2020|

Q – What is the difference between NPSHa and NPSHr ?

 

A – Nett Positive Suction Head AVAILABLE (NPSHa) is the absolute pressure at the pump inlet and is calculated by the system designer. Nett Positive Suction Head REQUIRED (NPSHr) is the minimum pressure required by the pump in order to operate successfully without any damage from pump cavitation and is set by the pump manufacturer. All good pump manufacturers will recommend the NPSHa is at least 0.5m greater than the NPSHr of the pump.