Metal seat assemblies for valves

摘要

A metal seat assembly (40) for sealing against the sealing surface of a valve member movable between open and closed positions. The seat assembly comprises an outer metallic ring (44) having an inwardly extending metal seal lip (58) hinged to the main body (48) of the ring by a reduced thickness portion. An intermediate metal backing ring (45) has a plurality of spaced fingers engaging the hinged metal lip to urge continuously the lip (58) into tight sealing contact with the valve member, and the backing ring may be adjusted to control the force exerted by the fingers against the metal lip. An innermost metal wiper ring (46) adjacent the flexible metal lip is urged continuously into contact with the sealing surface of the valve member to minimize contact of foreign matter with the sealing lip.