The Online Pump Magazine


NPSH Value

Net Positive Suction Head

Defined as the net energy head at the suction inlet of the pump. It is determined by the absolute energy head minus the vapour pressure head. The vapour pressure head must relate to the vapour pressure corresponding to the fluid temperature at the pump suction inlet.

The NPSHavailable value is the system-specific NPSH relating to the given Flow rate and the fluid characteristics.

The NPSHrequired is the lowest NPSH value at which definite cavitation criteria (i.e. wear due to cavitation, vapour formation, vibration, noise, head loss) can be contained.

Also see:
Avoiding Cavitation
System NPSHavailable
Working Pressure