What are methods of oil supply in C.O.W or crude oil washing ?

         Precaution:-

1. Slop tanks loaded by the ―Load-on-Top‖ procedure should be discharged entirely and then filled with fresh oil (crude oil free from water and residue) prior to COW.
   • It is considered better to discharge Driving Oil in Slop tank after washing a few tanks, not more than six tanks, and replace to fresh oil again as it may avoid the Driving oil to be sludge-full.

3. Bleed-off System (Open Cycle System):- A method in which a part of the oil being discharged is branched off to the tank cleaning line. Some terminals call this system in which cargo is discharged simultaneously with COW.