Fuel Overflow Reservoir: Description and Operation

This system provides a vapor space above the gasoline surface in the fuel tank. This area is enough to permit breathing space for the tank vapor valve assembly under all static and most dynamic conditions. Horizontally mounted tanks accomplish this by a raised mounting section for the valve assembly which is centrally located on the upper surface of the tank. Vertically mounted tanks use a centrally mounted vapor valve assembly on the uppermost surface of the fuel tank.