Abstract: The present invention includes a valve assembly having a fluid flow passage, a piston passage, a closure element and a moveable piston. The fluid flow passage extends from an inlet port to an outlet port. The piston passage transects and is oriented non-parallel to the fluid flow passage. The closure element interrupts fluid communication between the inlet and outlet ports. The piston being moveable within the piston passage between a first and second position, the piston including a head for opening the closure element wherein movement of the piston between the first and second positions enables fluid communication between the inlet and outlet ports. The valve assembly can include an explosive actuation mechanism for rapid actuation of the piston from the first position to the second position.

Abstract: There is disclosed a self-actuated pilot-controlled pressure-responsive valve for fluid pressure systems wherein the main valve is arranged to be seated by the fluid pressure in the system and a normally balanced piston and cylinder assembly pulls the main valve from its seat in response to elevated system pressure in a spring-loaded, tandem pilot and stabilizing valve assembly which in turn establishes a driving pressure differential across the piston, with the initial unseating of the pilot valve occurring substantially independently of the stabilizing valve which thereafter closes to hold the pilot valve open until reduced system pressure is achieved. At this time, the tandem valves operate as one with the pilot valve closing and the stabilizing valve opening against a force derived from system pressure through a conduit having a metering orifice which effects a pressure drop in the tandem valve assembly which insures full and chatter-free operation until the main valve is again closed.