Abstract: A sliding plate of a gate valve is guided in guide grooves formed in the region of a flow passage of the two-part gate valve housing. Each guide groove is bounded on both sides [upstream and downstream] by guide strips which extend into the flow channel. The guide strips have axially outwardly directed chamfers, and each such strip has a circular arcuate shaped recess. The recess, which starts at the upper entry point of the guide groove into the flow channel, extends to the lower third of the guide strip. The maximum depth of the recess is 3-5 mm less than the depth (t) of the guide groove 4b. The guide grooves 8a, 8b provide problem-free guiding of the sliding plate when said plate is moved to its closed position, particularly when said plate is moving through the lower third of the flow channel; nonetheless, the guide grooves 8a and 8b present only minimal flow resistance.

Abstract: A guide slot for a valve plate is bounded on both sides by guide strips projecting into a flow channel of a valve housing for the plate. These guide strips contain notches at intervals. The notches of one guide strip are offset relative to the notches of the other guide strip. When the valve is open, medium entering the guide slot through the notches on the inflow side is deflected in the guide slot before it leaves the guide slot again through the offset notches on the outflow side. This generates in the guide slot a lengthwise current leading to a self-cleaning action for combatting deposits. During the valve plate closing process, a permanent self-cleaning takes place over the entire closing travel zone. For this reason, the valve is particularly well suited for use in conveyor lines for thickish, powdery, granular or solids-containing media.

Abstract: The slanted closing rim of a valve plate includes a cylindrical portion at the rear side, having a diameter D1 which corresponds to the width of the plate and slightly exceeds the diameter D3 of the passage throat. A groove in the casing guides the narrow sides of the valve plate and accomodates a seal strip. The grooves partly closed at the front side by a guide strip which in the bottom zone of the passage throat is a semicircularly extending strip. The inside diameter D4 of this cylindrical strip approximately corresponds to that of the valve plate and its axis a extends at a level which is higher by half the difference between diameters D1 and D3 than that of the axis b of the throat passage. A slanted closing rim of the valve plate is provided with shear arcs on its frontal points on each of the side edges. The two shear arcs form a kind of a plowshare deflecting the medium from the seal.

Abstract: A shutoff device comprises a housing having a closable flow passage which is closed by a closing plate member which moves into a recess defined in said housing forming a receiving seat. The closing plate member is closed by the movement of a fluid pressure operated piston which moves the closing plate member rapidly into the closed position. In order to prevent the closing plate member from slamming into the valve seat and damaging the valve seat, there is provided a bolster member in the form of a stop which is disposed in the path of movement of a stop face connected to a piston rod of the fluid pressure's piston which is connected to the closing member.