Abstract: A double seat valve includes a housing with a pair of valve disks independently movable within the housing between a closed position and an open position. Further, the valve disks can also be moved as a unit. A hollow leakage space is located between the valve disks. Leakage can be conveyed from the space to the exterior of the housing. Each valve disk has a separate valve seat and a cylindrically shaped wall surface extends between the valve seats and defines the radially outer boundary of the leakage space. A seal mounted in the first valve disk contacts the first valve seat in the closed position and moves in sealing contact with the cylindrically shaped wall surface as the first valve disk moves from the closed position toward the open position so that leakage losses from the valve are avoided.

Abstract: A double seat valve, preferably a multi-way valve having two valve disks movable independently one against the other and against the valve seats, defines an annular space between the two valve disks which is connected to the outer atmosphere by a discharge conduit. According to the invention, at least three nozzles project axially in the discharging conduit to eject jets of cleaning liquid along the inner wall of the conduit, then the jets are bent radially outwardly along the lower surface of the upper valve disk, spread into circular segments which mix together along the boundary lines and then the mixed cleaning liquid is returned along the inner surface of the lower valve disk and discharged through the opposite wall of the discharge conduit.

Abstract: A double seat valve comprises a housing having a fluid inlet, a fluid outlet and two axially displaced valve seats between the inlet and the outlet. A pair of valve discs are moveable independent from each other between open and closed positions with respect to the valve seats, one of the valve discs engaging during its opening movements the other of the valve discs and forming in the closed position with the other valve disc a chamber from which a leak fluid passage leads to the surrounding air. A tubular displacement rod is connected at one end to the one valve disc and extends with a radially enlarged end portion into a cylinder of a main displacement mechanism which is axially displaced from the housing. The radially enlarged portion forms at the junction with the remainder of the tubular rod a shoulder and a piston is connected axially displaced from the shoulder to the enlarged portion.

Abstract: A double-seat valve unit with leakage control has a greater valve plate located below a smaller valve plate, adjusting bars connected with the valve plates and arranged so that the adjusting bar of the greater valve plate extends through the interior of the adjusting bar of the smaller valve plate and both valve plates move to an open position from above downwardly, a leakage conduit having a portion located inside a valve housing and movable outwardly, an annular gap formed between the adjusting bars for flowing of cleaning fluid, and a return valve formed by the lower valve plate.