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Because of their special location and function, tanker pumprooms are particularly hazardous and require special care and precautions. Over time, even small leakages of cargo into the pumproom bilges can produce dangerous levels of hydrocarbon vapours. Pumproom bilges should be pumped out to the slop tank after each cargo discharge and the pumproom should be washed periodically to remove any accumulated residues. The pumproom bilges must be washed before any repairs which would require maintenance personnel to enter the bilges.
If the pumps, valves and other pumproom connections are properly maintained, leakage will be minimal and cleaning may be required only after every second or third cargo. Whatever the frequency, it is vitally important that the pumproom bilges be maintained clear of hydrocarbons.
When cleaning is required, the bilges should be pumped dry, then flushed with water and pumped dry again. A washing team should be set up with two men at the pumproom lower level doing the washing and a support team at the top of the pumproom. Both men in the washing team must wear hydrocarbon detector alarms. If the bilges are especially dirty and therefore liable to generate significant quantities of gas while washing, then the washing team must wear breathing apparatus. If one man must enter the bilges to complete part or all of the washing, then he must wear breathing apparatus and a tended lifeline secured to his safety harness.
A work permit should be issued for the pumproom washing operation. Additional ventilation, using portable fans, should be provided to introduce fresh air into the bilges and the pumproom exhaust fan(s) should be run on high speed. The deck support team should have all necessary rescue equipment ready. Before washing begins, pumproom equipment which is likely to be damaged by water spray should be covered and sealed with plastic film.
With the ship listed appropriately and the pumproom bilge pump running, the washing team begins washing with the hand hose, working from the far corner of the pumproom toward the bilge suction. The hose size and flow rate should not exceed the capacity of the pumproom bilge pump/eductor and the hose should be fitted with a valve so that the flow can be controlled, or shut off by the nozzleman.
When the washing operation is completed, the hose team withdraws and the pumproom is ventilated for several hours (overnight if possible), to remove all hydrocarbon vapours. The chief officer should then test the pumproom with the combustible gas indicator at all levels, including the bilges (using the extension sampling hose).
With ventilation maintained as before, and with all of the tank entry precautions in place as for cleaning cargo tanks, the crew can enter the bilges and remove any sediment or scale remaining.

2.18.1 Pumproom bilge inspection
The time immediately after the pumproom bilges have been cleaned provides the best opportunity for a thorough inspection. The inspection should include (without being limited to):

  • Verify correct operation of the pumproom bilge alarm(s).

  • Check all valve, strainer and pump casing drain plugs are tight.

  • Check condition of all cargo piping drain valves and reach-rod connections.

  • Perform preventive maintenance thickness checks (if due), on cargo piping, sea-chests, lower sections of bulkheads and bottom plate pitting.

  • Examine and record the condition of coatings in bilges.

  • Replace any permanent electrical lamps which are only accessible from the bilges.

  • Check the condition of the gaskets and glands on all explosion-proof electrical fixtures.

  • Perform the sea valve integrity test using the following procedure:
  • Use the test fittings installed according to the illustration on this page. The test should be conducted in calm weather alongside a dock, or at anchor.
    1 Close the sea chest valve and block valve No.2.
    2 Drain water from the pipe section between the sea chest valve and block valve No.2.
    3 Close block valve No.1.
    4 Pressurise the pipe to about 50 psig (3.5 kg/cm2).
    5 Watch the pressure gauge for a pressure drop over 15 minutes.
    6 If a pressure drop is noted, check alongside the ship for bubbles and at test fitting 'B' for leakage. A balloon fitted over test fitting 'B' will indicate slow leaks. This will identify which valve is leaking.
    7 If the sea valve and block valve No.l are tight, block valve No.2 may be tested by opening block valve No.l and closing fitting 'B'. Re-pressurise the pipe to about 50 psig and watch for a pressure drop over 15 minutes.
    Immediately after pumproom cleaning, it may be desirable to complete any other pumproom preventive maintenance scheduled for in the near future.

    Refer to text for detailed instructions.
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