You suspect a problem with the centrifugal fire pump on your ship, and begin to slowly close the discharge valve. Your suspicion is confirmed when the __________.

Correct Answer: Option D — discharge valve is closed off and there is no change in the discharge pressure

A centrifugal pump's discharge pressure is a function of its speed and the impeller's design. If the discharge valve is closed and the pressure does not increase, the pump is likely failing to develop head, indicating internal wear, a broken shaft, or a missing impeller, confirming a mechanical or hydraulic failure.