287. On a slow-speed diesel engine vessel equipped with an ALCAP fuel oil purification system, what would be a symptom of an opening solenoid valve leaking by?

A leaking opening solenoid allows continuous fluid flow towards the sludge discharge, resulting in a faster rise in the purifier sludge tank level. This is because the solenoid, when malfunctioning, bypasses the intended sealing mechanism, leading to a constant, albeit small, discharge of separated product into the sludge tank.