Retracting ring seal valve

Abstract

A retracting ring seal valve is disclosed for adjustably restricting and permitting fluid flow in a two-direction fluid control system. In a particular embodiment the invention comprises a valve body that defines a central passage through which the fluid passes, a side chamber adjacent the central passage, and a sealing shoulder around a circumference of the passage. A gate assembly adjustably moveable between the central passage and the side chamber includes a ring seal surrounding a peripheral edge of a sealing surface of the gate assembly so that a retainer moves the ring seal to seal a flow gap defined between the sealing surface and the sealing shoulder of the valve body to restrict flow of fluid through the central passage. An actuating assembly secured between the gate assembly and the valve body both positions the gate assembly to restrict or permit flow of fluid through the passage and also moves the ring seal into and out of the flow gap. To open the retracting ring seal valve and thereby permit flow of fluid through the central passage, the actuating assembly first retracts the ring seal from simultaneous, sealing contact with the sealing shoulder and peripheral edge of the sealing surface so that any friction resulting from contact between the gate assembly and sealing shoulder is eliminated. The actuating assembly next pivots the gate assembly in a direction perpendicular to the flow of the fluids out of the central chamber into the adjacent side chamber.