Fluid pressure sealing ring for a valve

Abstract

A butterfly valve having a valve body and a valve disc which is rotated to produce an engagement with a peripheral edge of the disc and an annular seat or wall defined by a portion of an internal fluid passage in the valve body uses a seal ring member mounted in an annular groove in the valve body adjacent to the annular seat. The seal ring member includes a pair of bowed seal rings arranged in a 'V' within a triangular shaped annular recess in the wall of the fluid passage in the valve body. One side, i.e., an inner side, of each of the seal rings projects from the triangular recess to contact the edge of the valve disc to form a fluid-tight seal in response to fluid pressure acting on a convex face of a seal ring to flatten the seal ring. The other side of each of the seal rings contacts a respective corner of the recess with the convex faces of the seal rings facing each other. A preload member is located in the space between the convex faces of the seal rings to apply a pressure to the convex faces to induce a contact between the inner side of each of the seal rings and the peripheral edge of the valve disc.