Abstract: A metering valve, simultaneously controlling a plurality of flow paths with a single poppet movable into and out of engagement with a valve seat in a duty cycle operation has the sealing surfaces of the poppet and seat formed with an accurately flat surface finish to minimize leakage when the valve is closed. The seat surface is formed with recessed areas to reduce the area of contact with the poppet surface to reduce pull-off force while maintaining adequate contact area to dissipate the closing impact forces which are further minimized by controlling the flow of fluid from between the opposed surfaces during valve closure.

Abstract: Metering valves in diesel engine fuel injection systems are disclosed. The systems each include a high pressure fuel pump, a fuel distributor, at least one metering valve, and fuel injector nozzles. In the preferred embodiment, the valves are of a type having a spool or valving member which moves axially in a bore from a second position to a first position and while so moving an annular groove, defined in the circumferential surface of the spool, traverses a valve outlet passage at velocities independent of engine speed for metering fuel to the engine during the traversing time. The spool may be moved from the second position to the first position by a spring or a solenoid and in the reverse direction by a stepped cam, a spring, or a solenoid. The distributor blocks fuel metering to the engine during reverse movement of the spool.