VARIVENT® double-seal valves type C have a one-part valve disk with a double seal. They are used for mixproof separation of incompatible media at flow path intersections within the pipe system. Double seal valves are the economical alternative to the generally used double-seat valves. The valve`s isolation chamber is equipped with two rinsing valves which are provided for leakage detection and cleaning of the isolation chamber itself. It is possible to clean the isolation chamber both separately and during pipe cleaning.