A metallic slide ring seal (20, 21) is provided in the area of the cut-off gate (11) as first seal and on the exterior of the housing cover (12) turned away from the ball cock a second seal in the form of a groove ring (17) in a sealing groove (24) is provided. The sealing surface of the housing cover of the first seal is conical and the pin seal surface (21) opposite to the cover sealing surface is slightly convex. The drive pin (13) is effectively connected by a pin coupling (32) with the cut-off component.
