Engineering · Auxiliary — Pumps
A positive-displacement pump must be fitted with a relief valve because:
- AIt cannot build pressure
- BIt will continue to build pressure against a closed discharge until something fails✓ Correct
- CIt needs priming
- DIt runs only at one speed
Explanation
A positive-displacement pump delivers a fixed volume per stroke/revolution. Against a closed valve it keeps raising pressure until a line, seal, or the pump bursts, so a relief valve is essential.
Authority: Auxiliary Machinery (USCG engineering topic)
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