Net Positive Suction Head ("NPSH")

Net Positive Suction Head ("NPSH")

Net Positive Suction Head is the total inlet head plus the head corresponding to the atmospheric pressure minus the head corresponding to the vapour pressure.

NOTE: ‘NPSH’ and ‘total inlet head’ are referred to in the reference plane. The two references to NPSH are as follows:

(a) Net positive suction head required (NPSHR) A function of pump design, which is available from the pump manufacturer.

(b) Net positive suction head available (NPSHA) A function of the system in which the pump operates and which can be calculated for any installation.


In preparing this definition, we have drawn from various sources including Legislation, Codes, Standards and industry information, research and knowledge.  Like the english language, these definitions may subtly change from time to time. As such these definitions are provided solely on the basis that users will be responsible for making their own assessment of the definition and and are advised to verify all relevant representations, statements and information.