While operating the fuel oil centrifuge shown in the illustration, the bowl fails to open for sludge ejection. The probable cause is that __________. Illustration MO-0012

Correct Answer: Option A — the seal ring on the operating slide is defective

Hydraulic opening of a self-cleaning centrifugal bowl relies on operating water pressure overcoming the closing chamber pressure. A defective seal ring on the operating slide causes operating water to bypass, preventing the pressure build-up needed to force the sliding bowl down for sludge ejection.