Pressure controlled apparatus for sealing shutoff devices located in pipelines

Abstract

An apparatus for sealing shut-off devices located in gas or liquid transporting pipelines having a sealing arrangement, which seals the shut-off device against a casing, the sealing arrangement having a gasket engageable against the circumferential surface of the shut-off device, a seating ring supporting the gasket, two chambers which can be supplied in a controlled manner with a pressure medium, and a method by which the gasket can be raised from the circumferential surface and pressed against the circumferential surface. The sealing arrangement has a driving member positively connected to the seating ring and a displaceable intermediate piston located on the driving member. The first chamber is located between the driving member and the intermediate piston and when subject to the action of the controlled pressure, brings about a movement of the driving member in the gasket raising direction. A second chamber located between the intermediate piston and the casing, when subject to the action of the controlled pressure, brings about a movement of the intermediate piston in the pressing direction. Between the seating ring and the intermediate piston are positioned spring elements which are biased in the pressing direction.

Dependencies are inferred from the claim text.