Using an approved simulator, in the laboratory, or aboard ship, given access to a fuel oil or lube oil purifier.

Performance requirement

Behavior Standard
The student will: During assessment, the student shall, at a minimum:

Prepare to clean an oil purifier

  • shut down unit and secure liquid inlet and outlet valves
  • lockout and tagout the unit

Disassemble the purifier

  • follow manufacturer’s instructions
  • cause no damage to components
  • use specialized tools where required

Clean the purifier

  • soak dirty parts in cleaning fluid
  • remove accumulated sludge from all components
  • wipe down components with clean rag

Inspect the purifier

  • check parts for residual oil or sludge, remove if present
  • check bowl cover gasket for suitability, replace if necessary
  • correct any observed deficiencies

Reassemble the purifier

  • follow manufacturer’s recommendations
  • install disks in correct order
  • tighten bowl ring with bowl ring wrench
  • secure bowl cover and oil supply tube
  • insure bowl can rotate freely without binding


Assessed in EN‑4131 Internal Combustion Engines II.


  1. Table A-III/1 OICEW-C2.3
  2. NVIC Task

Lab Manual

EN-4131 Lab Manual

See the Assessment Guidelines for additional specifications of behavior and standards.