Patent ID: 6837219

Claim:
A ported pressure relief valve for use in a fuel system supplying fuel to an internal combustion engine, the valve being interposed between a fuel pump pumping fuel from a source of fuel and a delivery system by which fuel is routed from the fuel pump to the engine, comprising: means returning excess fuel from the fuel pump back to the fuel source when the engine is running and including a controlled constant fuel return orifice opening into a fuel passage by which fuel flows back to the fuel source through the orifice while the engine is running; check means preventing flow from the delivery system back to the fuel source when the engine is off so as to retain sufficient pressure in the delivery system that the engine will readily start; and, pressure relief means for draining fuel from the delivery system back to the source of fuel in response to a pressure build up in the fuel delivery system above a predetermined pressure level so to prevent an overpressure condition which would otherwise damage the fuel delivery system, each of the check means and pressure relief means including a valve having a valve member and means urging the valve member to a closed position, the fuel pressure required to open the valve member for fuel to flow through the respective means being determined by a force exerted on the respective valve by the means urging the valve member to its closed position.