Patent attributes
A reverse flow valve for metering high pressure gaseous media, such as ignition media to the injectors of a scramjet engine in a hyerpsonic flight vehicle, has a metering member that moves parallel to the flow direction of the metered media and throttles the valve in a direction counter to the flow direction. This reduces side loading on the metering member and permits the use of a lighter and smaller actuating mechanism. The metering member can be a pintle having a uniquely configured pintle seat providing bubble tight shut off of the inlet flow without effecting the critical flow contour of the media. The pintle can be driven by a piston that is responsive to push-pull forces of pressurized drive fluid under servo control. The drive fluid is isolated from the gaseous media by a primary seal, which can be seated on the piston without deformation by a seal retainer. The drive fluid can be fuel diverted from the sustained combustion fuel system of the vehicle so that a separate hydraulic system is not required.
