Patent ID: 7311292

Claim:
A shut-off valve comprising: (a) a body having a chamber formed therein, the chamber including a first duct and a second duct each extending from the chamber, the chamber and each duct adapted to accommodate a fluid when fed through the body; (b) a closure member including a central core, the core having a head oriented toward the first duct, the head having a larger diameter than the first duct and having a convex sealing face with respect to the first duct; and (c) a flexible circular disc oppositely disposed from the first duct, the disc integrally formed with the head extending along both sides thereof and peripherally fixed to outer surfaces of the chamber whereby the disc separates in a sealed manner the chamber from an operating means operatively coupled to the body, the closure member selectively positionable in one of an open position and a closed position via the operating means, the convex sealing face of the head disengaged from an inner opening of the first duct in the open position of the closure member thereby permitting free flow of the fluid between the ducts, the convex sealing face of the head engaged with and partially entering the first duct inner opening in the closed position of the closure member thereby preventing the free flow of the fluid between the ducts, the disc having a substantially smooth transition to an internal wall of the second duct in the closed position of the closure member, the valve configured to operate in at least two positions including a first valve position where the head is above the opening of the first duct in an open position of the closure member and a second valve position where the head is below the first duct opening in an open position of the closure member, the substantially smooth transition of the disc in the closed position of the closure member preventing collection of fluid within the chamber regardless of whether the valve is in the first position or in the second position.