Abstract: A gate valve apparatus suitable for controlling the flow of fluids in a conduit, especially gases in high temperature applications, is disclosed. The apparatus includes a gate member adapted for sliding movement through an aperture in the gate valve assembly. Each opposing side of the aperture has fixedly mounted cooperating flat sealing strips to seal the aperture in both the conduit-open and conduit-closed positions. In certain embodiments a plurality of substantially parallel gate members, each having aperture sealing means, may be used to provide increased sealing effectiveness for highly toxic gaseous mediums.

Abstract: A snap-in metal strip, longitudinally bent into a V shape with the upper ends of both arms of the V being turned outward to the horizontal, thus creating longitudinal lips on the strip, is used to seal an elongate gap, for example a narrow space between adjacent, closed blades in a louver damper. The strip is releasably held on one side of the gap by means of two, opposed, crevice-like channels into which the lips of the strip fit.

Abstract: A sliding gate valve comprising a housing; a sliding gate; an enclosed void space between the gate side edges and the wall of the housing when the gate is in the closed position; and a purge line for injecting pressurized fluid into the void space; improved by gate side edge sealing means comprising a downstream seat mounted on the interior wall of the housing and an upstream seat assembly comprised of a rigid, elongated channel on the interior wall of the housing, parallel to, and upstream of, the gate when in the valve-closed position, the channel having a back wall and at least one side wall, the back wall being substantially parallel to the gate; a rope positioned lengthwise in the channel; the channel having an elongated metal strip flexibly attached along the first of its two long edges to a side wall of the channel so as to sandwich the rope between the back wall of the channel and the rear surface of the metal strip; the seat assembly being positioned such that when the gate is closed the gate's upstr

Abstract: Sealing means for sealing between a moving member and a fixed frame with which the moving member cooperates, said sealing means comprising rigid, elongated, channel means (on either the frame or the moving member), said channel having a back wall and at least one side wall; a rope which is resiliently compressible across its width positioned lengthwise in said channel; and an elongated metal strip having opposing front and rear surfaces, said strip being flexibly attached along the first of its two long edges to a side wall of the channel so as to sandwich the rope between the back wall of the channel and the rear surface of the metal strip, the channel means, rope, and metal strip being positioned such that the complementary part (either the moving member or the frame) can press against the front surface of the metal strip in sealing engagement therewith, urging the strip against the rope, the resilience of the rope providing a pressure counter to that exerted by the complementary part.

Abstract: A valve assembly having a frame with a fluid flow opening therethrough; at least one blade mounted in the frame opening to be movable from a valve open position, in which fluid is able to flow through the frame opening, to a valve closed position, in which fluid is blocked from flowing through said frame opening, said blade having opposing upstream and downstream surfaces, an interior chamber lying between said surfaces, and edge portions joining said surfaces together; a first seat member carried by at least one of said edge portions; a second seat member carried either by an interior wall of the frame or by the edge portion of an adjacent blade; said first and second seat members being so constructed and arranged that when the blade is in the valve closed position the seat members seat against one another to block the flow of fluid around the blade; said first and second seat members being formed such that when the seat members are seated against one another the seat members define an enclosed cavity betwee

Abstract: Sealing means for a sliding gate valve with a frame having a bottom frame member, a top frame member with an aperture therein generally transverse to the direction of fluid flow through the valve, and parallel, rectilinear side frame members and a gate having parallel, rectilinear sides adapted for sliding movement through the aperture to a closed position within the frame to restrict the flow of fluid through the frame. The seal is effected by a flange that is fixedly mounted on at least one frame member downstream of the aperture and in the interior of the frame and is parallel to the gate, and a longitudinal strip of resilient material fixedly mounted on at least one side frame member in the interior of the frame and in the plane of the gate. The flange is adapted to contact the downstream surface of the gate and limit the gate's downstream displacement due to the pressure of fluid when it is in the closed position and subjected to fluid pressure against its upstream surface.

Abstract: A valve assembly comprising a housing constructed of a material which will expand when heated, a plurality of closure elements inside the housing that can be rotated between valve open and valve closed positions, each element being mounted on its own shaft that is journaled in the housing and that has an external end portion extending through the housing with the shafts being parallel to one another and lying in the same plane at equidistant intervals, a plurality of cranks of equal length extending radially from the end portion of each shaft for rotating the shaft, and drive arm means linking the plurality of cranks so that rotation of one of the cranks causes all of the cranks, shafts, and elements to rotate in unison is improved by the drive arm means being temperature-compensating three-link mechanisms connecting each of the cranks and comprising (a) a first floating link pivotally attached at its first end to the non-shaft end of one of the cranks, (b) a second floating link of the same length as the fir