Patent ID: 8113228

Claim:
A suction valve for a pipe line in which a medium flows, whereby the flow in the pipe line can be closed and can be regulated and whereby back flow can be prevented, the suction valve comprising: a valve housing through which the medium flows, said valve housing including a counter seating face which surrounds an upstream portion of the medium flow in the valve housing and a stationary part in the valve housing; a movable part which is placed in said valve housing and which is movable relative to said stationary part between a closed position where the movable part engages the counter face of the valve housing and prevents flow through said valve housing and an open position where flow through said valve housing is permitted, said stationary part and said movable part together forming a working cylinder of a piston part and a cylinder part with a working space therebetween so that said movable part can be moved by a downstream pressure of the flow medium being present or absent from the working space; an outlet valve by which the downstream pressure of the flow medium is led into said working space, said outlet valve being located inside of the working space, and said outlet valve including a tap hole which is open to a downstream portion of the medium flow in the valve housing.