Patent ID: 7823633

Claim:
A valve apparatus arranged for support within a fluid passage to control fluid flow between the fluid passage and a fluid delivery conduit having one end thereof disposed within the fluid passage to facilitate delivery of fluid between an interior and an exterior of the fluid passage via a pressure difference between the fluid passage and the fluid delivery conduit, the valve apparatus comprising: a valve housing having an open end and having a first housing port and a second housing port spaced along the valve housing, each housing port communicating with an exterior and interior of the valve housing; a driven member supported within the valve housing; a drive mechanism coupled to the driven member to effect displacement of the driven member along the valve housing toward and away from the first housing port into extended and retracted positions respectively; and a closure member slidably coupled to the driven member to be slidable relative thereto along the valve housing, the closure member having a closure member port communicating with an interior and exterior of the closure member; the driven member and closure member arranged to close and open the closure member port during movement of the driven member toward the extended position and the retracted position respectively to respectively induce and relieve a pressure differential that, when induced, is exerted on the closure member by fluid entering the valve housing to slide the closure member along the driven member to a closed position in which the closure member closes the first housing port; wherein a sealing arrangement associated with the driven and closure members is defined within the valve housing and arranged to first close off the closure member port between the driven member and the closure member under movement of the driven member from the retracted position toward the first housing port relative to the closure member and to subsequently close off the first housing port between the closure member and the valve housing under movement of the closure member toward the first housing port subsequent to closing of the closure member port.