Abstract: In a double seat valve with leak control, two valve discs are located within a housing and each is movably displaceable between an open position and a closed position by adjusting devices. The valve discs are shaped to form a hollow space between them. One adjusting device moves one of the valve discs into the open position and into contact with the other valve disc and displaces the other valve disc into the open position. Each valve disc has a separate adjusting device for displacing it into the open position but not into contact with the other valve disc. A shaft is connected to each valve disc and the adjusting device or devices moves the disc via its shaft. One of the shafts is tubular and its hollow interior is connected to the hollow space defined by the valve discs and provides a leaking liquid line from the hollow space. In one embodiment, a cleaning medium supply line is located in the tubular shaft and supplies cleaning medium into the hollow space from a nozzle.

Abstract: A double-seat valve has a first valve member and a second valve member which abut against one another after a predetermined stroke to an open position, so as to form a closed chamber. A draining conduit communicates with the thus-formed chamber. The valve members are mounted on a common shaft. One of the valve members is variable so that its seating face is displaceable relative to a point in which this valve member is mounted on the common shaft. The one valve member may be elastically deformable or corrugated.