As Chief Engineer of a slow speed diesel engine vessel equipped with an ALCAP fuel oil purification system. You note a definite increase in the rate at which the purifier sludge tank is rising. One of the first items to check on your system would be which of the following?

Correct Answer: Option A — The opening water solenoid for leak through.

An escalating sludge tank level in an ALCAP system frequently indicates unwanted water entering the clean oil or sludge circuit. An opening water solenoid leaking through continuously bleeds water into the system, prematurely triggering discharge cycles and filling the sludge tank.