What type of tank holds fuel before it is cleaned?

The type of tank that holds fuel before it is cleaned is known as a fuel oil tank. This tank serves as a storage point for fuel that is waiting to undergo processing or filtration to remove impurities and contaminants. Fuel oil tanks are crucial in ensuring that the fuel is maintained in a suitable condition before it is delivered to combustion systems or other applications.

The other options represent different types of tanks with distinct purposes. For instance, a feed water tank is used to store water that will be treated and converted into steam for power generation or heating. A storage tank generally refers to any tank that holds materials, but its designation varies based on content, such as chemicals, water, oil, or solvents. A separation tank, on the other hand, is specifically designed to separate different types of liquids or phases, such as oil from water, rather than merely storing untreated fuel. Hence, the specific function of holding fuel before cleaning aligns with the definition of a fuel oil tank.