What are checks carried out prior to COW or crude oil washing?

Follow the “Crude Oil Washing Operations and Equipment Manual” and check the items below whenperforming the crude oil washing.

1. Before starting the crude oil washing work, confirm that the concentration of oxygen in the tank is below 8% by volume.
   • Measure the oxygen concentration in the tank at any of the positions mentioned below from an adequately safe distance from the inert gas intake.
   • At a height of 1 meter below the deck and at the centre of the void space below deck.
   • At the measurement height required by terminal regulations
2. Confirm that the inert gas system is working correctly.
   • The oxygen concentration at the inert gas floor exist should be maintained at less than 5% by volume except during temporary fluctuations such as low loads or load fluctuations of the boiler. (If the concentration exceeds 5% by volume, immediately investigate the cause and adopt the necessary measures.Maintain the pressure in the tank at more than +1.961 kPa (+200 mmAq) during the crude oil washing work.)
3. Carry out pressurize tests for the COW line and check for abnormalities before entering port.
4. Check the items related to equipment and method of implementing the COW work.
5. The equipment and method mentioned below should be thoroughly understood before performing COW work.