Engineering · Auxiliary — Pumps
Net positive suction head (NPSH) available to a centrifugal pump must remain:
- ABelow the pump's required NPSH
- BAbove the pump's required NPSH to avoid cavitation✓ Correct
- CEqual to the discharge pressure
- DAt zero for best efficiency
Explanation
NPSH available (from suction pressure minus vapor pressure and losses) must exceed the pump's NPSH required; if it falls below, the liquid flashes to vapor at the impeller and the pump cavitates.
Authority: Auxiliary Machinery (USCG engineering topic)
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