Seat ring seal for ball valves

摘要

A shut-off valve (10) having a shut-off member, preferably a ball cock (17), which is mounted in a floating manner in seat rings (12, 18) and seals off metal on metal. Recessed into the seat surfaces (20) of the seat rings (12, 18), which surfaces form a metal-to-metal seal, are sealing grooves (19) and additional snugly fitting sealing elements (16, 21) are inserted in the sealing grooves (19). The sealing grooves (19) run transversely to the main direction of pressure (22). The lower sealing element (16) in the main direction of pressure has a smaller internal diameter and the upper sealing element (21) in the main direction of pressure has a smaller external diameter than the respectively associated sealing grooves (19). The sealing elements (16, 21) are prestressed axially with round sealing rings (13). <IMAGE>