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.

ALCAP systems automatically adjust water content based on sludge monitoring. A leaking opening water solenoid allows control water to continuously bleed into the bowl, prematurely triggering sludge discharge cycles and causing an abnormal rise in the sludge tank accumulation rate.