Fluid-pressure-regulating valve device

Claim 1

A fluid-pressure-regulating valve device comprising: a. a fluid pressure inlet, b. a fluid pressure outlet, c. first passage means through which fluid under pressure may flow from said inlet to said outlet, d. valve means interposed in said first passage means, e. valve-operating means operably connected to said valve means, said valve-operating means being subject to a force acting on one side thereof and movable responsively thereto in one direction for operating said valve means to an open position in which communication through said first passage means is open, f. venturi means disposed in said first passage means communicating fluid pressure in said first passage means to a pressure chamber adjacent the opposite side of said valveoperating means via a passageway having one end opening to said venturi means and other end opening to said chamber, g. said valve-operating means being movable in a direction opposite to said one direction in response to buildup of fluid pressure in said pressure chamber to a predetermined value sufficient for overriding said force to effect operation of said valve means to a closed position in which communication through said first passage means is closed, h. said venturi means being effective for maintaining the pressure of fluid in said pressure chamber acting on said opposite side of said valve-operating means at a lesser degree than that delivered to the outlet for sustaining said valve means in a fully opened position until such pressure at the outlet attains said predetermined value, and i. second passage means communicating said fluid pressure chamber with the side of said valve means opposite that adjacent the first passage means for effecting a balanced state of fluid pressure on both sides of the valve means, when in its Closed position, at a level corresponding to that of delivered pressure at the outlet.