Returnless Fuel System (RF)

Returnless Fuel System (RF)

In Returnless Fuel (RF) supply systems, the fuel-pressure regulator and the fuel filter are installed in the fuel tank. When this system is used, the fuel return line connecting the fuel distributor in the engine compartment with the fuel tank can be eliminated. The excess fuel supplied by the electric fuel pump directly enters the fuel delivery unit s storage vessel from the pressure regulator. Only the quantity of fuel injected by the injection valves is pumped to the fuel distributor in the engine compartment. The advantage of eliminating the return line is that fuel heated in the engine compartment does not flow back into the fuel tank and increase the fuel temperature. This leads to a further decrease in the HC emissions in the fuel tank and thus relieves the tank ventilation.