On a vessel of at least 1,000 HP, on a simulator, or in a laboratory.

Performance requirement

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

Prepare to replace flange gasket.

  • isolate and lock out system
  • select appropriate gasket material
  • clean flange surfaces
  • check flange surface for flatness and imperfections

Fabricate a new flange gasket

  • measure flange
  • use packing cutter to cut gasket material
  • use hole punch to make bolt holes

Reassemble flange with new gasket

  • center the gasket on the flange
  • use a torque wrench, well-lubricated fasteners, and hardened flat washers to ensure even force distribution
  • tighten bolts in one-third increments, according to proper bolting patterns to compress the gasket uniformly
  • make a final check pass at the target torque value moving consecutively from bolt to bolt

Check flange for leakage

  • open isolation valve slowly
  • check for leaks


Assessed in EN‑2231 Sea Term II: Marine Engineering.


  1. Table A-III/1 OICEW-C1.7
  2. NVIC 17-14 Task 8.2.B

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