Abstract: A precision valve control for an hermetically sealed hydraulic valve system which operates with a solenoid driven magnetic actuator. The magnetic actuator forms a toroidal magnetic force field of varying strength which causes controlled movement of a core rod linked to a pilot. The pilot, in turn, causes actuation of the main disc to the desired valve position. Actual valve position is remotely ascertained, by position of the magnet (or core) within the magnetic field, by means of a Linear Variable Differential Transformer (LVDT). The LVDT creates variable voltages predeterminately related to position of the rod within the magnetic field. The LVDT voltage is compared, by an electronic comparator, to an input command voltage, calibrated to a specific valve position. Deviation between the LVDT voltage feedback signal and input command voltage signal causes generation of an error signal which is amplified and applied to the solenoid to vary the magnetic field to correct the valve position.

Abstract: A self-modulating control valve for high pressure fluids, particularly gas in three interacting pressure chambers are provided in association with the main disc which includes two piston portions of different diameters, one of which operates as a spool valve to meter fluid flow through valving ports to a pressure stabilizing chamber formed in the main disc and also to the outlet side of the valve. Fluid flow to the pressure chamber which includes the large piston portion is through a metering orifice which drops the pressure in combination with unseating the valve, allowing the pressure in the chamber which includes the smaller of the piston portions to contribute the unseating forces for the main disc.

Abstract: Programmable pressure reducing apparatus for throttling fluids under high energy in which standardized parts can be stacked and nested to achieve a wide range of restriction and expansion points interposed in tortuous fluid flow paths which divide and recombine the fluid a plurality of times to dissipate high energy without incurring cavitation.

Abstract: The pressure responsive, pilot actuated, modulating valve comprises a main valve assembly which defines with the housing a first chamber and controls flow of fluid from an inlet port to an outlet port. A pressure responsive piston is provided which defines with the housing a second chamber. A vent passageway is provided in the piston for communicating the second chamber with the outlet port. A pilot valve assembly is provided to control flow through the vent passageway. A means is provided for selectively actuating the pilot valve assembly. A discharge orifice is comprised in the main valve assembly for communicating the vent passageway with the outlet port. A vent valve assembly is disposed to control flow of fluid between the first chamber and the discharge orifice.

Abstract: The valve assembly for the control of flow of liquid from a source of liquid at high pressure to a place of use has at least one restrictive orifice adjacent a movable valve member and valve seat to provide pressure drops in series in the liquid each of which pressure drops is of a magnitude sufficient to maintain the liquid pressure above the vapor pressure of the liquid at the inlet of the valve assembly so that cavitation does not occur. The restrictive orifice varying in flow area automatically in direct proportion to the variable flow area between said movable valve member and the valve seat.

Abstract: An improved solenoid operated valve utilizing a pilot valve nested within a main valve having a dual mode capability, fluid pressure assisted or solenoid powered, wherein the main valve's stem section is mounted within a tubular pilot armature and stem for movement toward the main armature to thereby open the pilot valve and then the main valve.

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.