In an Oil Circulating and Filtering System it is frequently necessary or desirable to arrange a gravity return of the oil from the bearings and gears directly into a specially designed Receiving Tank. It is important to recognize that the design of this dirty oil receiving tank is for purposes other than mere storage of the system oil. One of the basic features of the tank is that it serves as a contamination trap. This is accomplished by the physical size of the tank, which provides a minimum oil velocity as it passes from the return end strainers to the floating suction. This minimum velocity and the controlled flow pattern designed into the oil receiver provides for the maximum amount of settling in the retention time provided, thus enabling the maximum amount of solids and free water to settle out as the oil passes through the tank.