Patent ID: 7708066

Claim:
A downhole tool comprising: a body having a bore formed therethrough and at least one end adapted to threadably engage one or more tubulars; a sliding sleeve at least partially disposed in the body, the sliding sleeve adapted to move between a first position and a second position within the body; a valve assembly comprising a valve member having an arcuate cross section wherein the valve member is adapted to pivot between an open and closed position within the body; and a valve seat disposed in the body, the valve seat having a complimentary arcuate cross-section adapted to provide a fluid tight seal with the valve member, wherein an interface between the valve member and the valve seat, in the closed position, is angled relative to the longitudinal centerline of the body, such that, proceeding radially outward, the interface extends away from a vertex of the arcuate cross section of the valve member, and wherein the angle of the interface is between 1 degree and 89 degrees relative to the longitudinal centerline of the body.