5.6 Crude oil washing (see section 5 of the Crude Oil Washing Operations and Equipment Manual)
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - Specifications and Manuals - Inert Gas Systems - 5 Application to Cargo Tank Operation - 5.6 Crude oil washing (see section 5 of the Crude Oil Washing Operations and Equipment Manual)

5.6 Crude oil washing (see section 5 of the Crude Oil Washing Operations and Equipment Manual)

  5.6.1 Before each tank is crude oil washed, the oxygen level shall be determined at a point 1 m below the deck and at the middle region of the ullage space and neither of these determinations shall exceed 8% by volume. Where tanks have complete or partial wash bulkhead, the determination should be taken from similar levels in each section of the tank. The oxygen content and pressure of the inert gas being delivered during the washing process should be continuously recorded (see regulation 62.16.1.1 and .2).

  5.6.2 If, during the crude oil washing:

  • .1 the oxygen level of the inert gas being delivered exceeds 8% by volume; or

  • .2 the pressure of the atmosphere in the tanks is no longer positive;

then washing must be stopped until satisfactory conditions are restored. Operators should also be guided by 4.5.2.


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