USCG Exam PracticeLube oil and fuel oil systems
When a centrifuge is operated as a purifier rather than as a clarifier, what is the primary operational difference?
- A. A purifier uses a higher bowl speed to remove only solid contaminants
- ✓ A purifier requires a water seal established by priming with fresh water before oil is admittedCorrect
- C. A purifier uses a smaller gravity ring to increase throughput rate
- D. A purifier bypasses the disc stack to allow faster separation of heavy sludge
Why B is correct
NAVEDTRA 14075 §3-4 states that a centrifuge run as a purifier separates water as well as solids and requires a liquid seal (water dam) established by priming with fresh water before oil is admitted. A clarifier removes only solids and uses no water seal.
Cited:NAVEDTRA 14075 §3-4