LEAK-FREE SWITCHING PROCESS FOR A DOUBLE SEAT VALVE AND SEALING ARRANGEMENT FOR CARRYING OUT THE PROCESS

摘要

A process is disclosed for switching without leaks a double seat valve by means of radial sealing means shaped in a slide-shaped closure member. In order to ensure leak-free switching, to increase the service life of the radial sealing means and to improve their microbiologically irreproachable arrangement in the closure member, as compared to solutions of the state-of-the-art, in a first embodiment of the process the radial sealing means (1, 1*) are guided and remain sealed in the cylindrical valve seat surface (5) while the valve is opened, whereas sealing means (2, 2*) provided in the second closure member (4) sealingly engage an end section (E) of the radial sealing means (1, 1*) and the end section (E) is sealingly surrounded by the sealing means (2) when the valve is further opened and when it reaches its open position. In order to carry out this process, a sealing arrangement is characterised by axial sealing means (2, 2*) that have an axial sealing surface (2a) that co-operates with an axial valve seat surface (5a), as well as radial sealing surfaces (2b) that co-operate with the end section (E) of a sealing surface (1a) of the radial sealing means (1, 1*), whereas the radial sealing surface (2b) sealingly surrounds the end section (E) when the closure members (3, 4) engage each other.