RFPEW Task 1.2.C

Shift and clean a basket-type duplex strainer

MMA Method

In order to satisfy NVIC 07-14 Task 1.2.C , MMA students must:

NVIC Method

See NVIC method.

STCW Competence Knowledge, Understanding, and Proficiency

Carry out a watch routine appropriate to the duties of a rating forming part of an engine-room watch.

RFPEW-A1.3 Safe working practices as related to engine-room operations
Condition Behavior Standard

On a vessel, or in a laboratory,

the candidate shifts and cleans a basket-type duplex strainer.


All The assessment applies to all RFPEW endorsements.

The candidate:

  1. Ascertains the need for cleaning a duplex strainer (but does not clean an in-service suction strainer);
  2. Ensures that the change-over handle is loosened;
  3. Ensures that the strainer being changed to is either pre-filled or is carefully filled by changing over without loss of pressure to protected machinery;
  4. Ensures that the selector handle is positioned on the element not being cleaned, then tightened;
  5. Loosens the idle strainer-lid fasteners or hold-down dogs as appropriate;
  6. Ensures that the strainer house is depressurized and that the selector-plug valve is not leaking;
  7. Removes fasteners or positions dogs clear out of the way;
  8. Lifts up strainer lid and sets it aside;
  9. Lifts up and removes the strainer basket;
  10. Cleans the strainer basket;
  11. Reinstalls the strainer basket;
  12. Inspects mating surfaces of housing and lid, and scrapes, cleans, and replaces gasket as necessary;
  13. Replaces and aligns the lid on top of the strainer housing;
  14. Hand-tightens the bolts or firmly tighten hold-down dogs;
  15. Wrench-tightens the bolts or firmly tighten hold- down dogs;
  16. Checks the strainer housing for leaks;
  17. Cracks the strainer element selector-handle towards the idle strainer housing to slowly admit sea water and pressurize housing;
  18. Repositions the selector handle fully towards the strainer housing in service;
  19. Notifies watch engineer of any unusual or unsafe conditions; and
  20. Takes proper action to prevent safety and pollution violations.