SEALING DEVICE FOR A VALVE

摘要

There is a valve body formed with a cavity and an annular recess which extends around the periphery of the cavity and which has a side recess face and a bottom recess face which joins to the wall of the cavity. A valve member is mounted within the cavity so as to rotate about an axis of rotation substantially perpendicular to the central longitudinal axis of the cavity, and whose surface is part of a surface of revolution generated by rotating a curve about the axis of rotation. An annular retainer is located in the valve body in a manner to oppose the annular recess and a flexible annular seal is partly located in the recess. The flexible seal has an inner peripheral surface adapted to cooperate with the outer surface of the valve member to form a seal therebetween, and an outer peripheral surface in contact with the side recess face of the recess. An annular pressure member is located between the retainer and valve body and which has an inner peripheral surface adapted to cooperate with the outer surface of the valve member and a surface facing the valve body adapted to cooperate with the surface of the valve body should the annular seal be destroyed. A spring is located between the retainer and the pressure member and which urges the pressure member toward the valve body.