Which of the following problems will occur if a manually cleaned disk-type centrifugal lube oil purifier contains insufficient sealing water prior to admitting oil flow to the bowl?

Correct Answer: Option A — Lube oil will discharge from the heavy phase discharge port to the sludge tank.

Without an initial sealing water seal inside a disc-type centrifugal purifier bowl, the incoming oil overcomes the outer radius balance, bypassing the disc stack and discharging directly through the heavy phase port into the sludge tank.