You are planning to use a crude oil washing system. What precaution must be taken with the source tank for the washing machines?

Correct Answer: Option C — At least one meter must be decanted from the source tank.

Crude oil washing (COW) operational standards require decanting at least one meter of water and sediment from the source tank prior to washing. This removes free water layers, prevents pump suction loss, and ensures dry oil is delivered to the washing machines.