Abstract: A wedge-shaped gate member, movable by a valve rod, is disposed in a housing and can be pressed against valve seats on two ends of aligned tubular conduit sections. Each interior space of the tubular conduit sections is connected to the housing interior space via a respective auxiliary valve device. These devices each work as check valves, whereby when the wedge sluice valve is closed a pressure is maintained in the housing interior space which is equal to the pressure in the tubular conduit section which is serving as the feed pipe. The pressure in the housing interior space presses the wedge-shaped gate member against its associated seats and ensures a reliable seal. The wedge angle of the wedge-shaped gate member is relatively large, and said member is slidably guided in the housing. In this way, the friction between and the wear of the sealing surfaces are reduced.