James E. Sternenberg - Houston TX
William W. Broadway - Houston TX
FMC Corporation - San Jose CA
An annular valve seat having a resilient metal seal for use in a variety of types of valves provides positive control of fluid flow, with effective metal-to-metal sealing, long life and easy replacement of the seal. The metal seal is in the form of an annular ring comprising approximately one-quarter of a torus that cooperates with the valve's flow control element to establish a metal-to-metal fluid seal which is especially useful at relatively high temperatures. A first edge portion of the torus is held in position against a radial surface of the valve's body by a retainer ring which centers the torus about the flow control element. When the valve is closed the flow control element presses against the outside portion of the resilient metal torus forcing the free edge of the torus against a portion of the retainer ring so that the seal is loaded as a structural span supported at the ends by the valve's body and the retainer ring. The flow control element presses against the central portion of the span which deflects into a concave form to press tightly against the flow control element to effect a fluid-tight seal. The retainer ring and the torus are held in position in the valve body by a plurality of screws so that the ring and torus may be quickly and easily removed for servicing or for replacement.