Abstract: A damper mechanism of the slide gate type includes two curved seal segments positioned in back-to-back abutting relation to function as the primary flue seal. A seal door when closed extends between the upper ends of the seal segments and applies compression to the spaced appart ends to form, in combination with the seal segments, a closed chamber which functions as a secondary seal. Means are provided for applying a thrust force to the upper end of one of the seal segments to move that seal segment into abutting relation with the other seal segment when the slide gate is withdrawn. In a preferred embodiment, the thrust force is applied by the seal door during its closing. In another preferred embodiment, the closed chamber formed by the seal door and seal segments is enlarged and compressed air is pumped into the chamber to improve its functioning as a secondary seal.

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.