Abstract: The sliding parts, the guides and interlocking portions of the interlocking guides and slides of a slide valve are all disposed away from a flow path through the valve. Additionally, the portions of the interlocking guide on the slide or disc of the valve that interlock with the guide on an orifice plate are connected to the slide or disc by welds instead of bolts, greatly increasing durability. As the slide or disc moves in and out to control the flow rate precisely, the guides of the slide or disc move with it. Because the sliding surfaces of the orifice plate and the slide or disc are outside of the flow path, they are consequently not subjected to erosion from the flow through the valve. Accordingly, all critical sliding surfaces are not exposed to the flow path and are greatly increased in durability.

Abstract: The sliding parts, the guides and interlocking portions of the interlocking guides and slides of a slide valve are all disposed away from a flow path through the valve. Additionally, the portions of the interlocking guide on the slide or disc of the valve that interlock with the guide on an orifice plate are connected to the slide or disc by welds instead of bolts, greatly increasing durability. As the slide or disc moves in and out to control the flow rate precisely, the guides of the slide or disc move with it. Because the sliding surfaces of the orifice plate and the slide or disc are outside of the flow path, they are consequently not subjected to erosion from the flow through the valve. Accordingly, all critical sliding surfaces are not exposed to the flow path and are greatly increased in durability.

Abstract: A valve (e.g., shutoff or regulating) is provided including a valve body having a fluid passage and a disc assembly. The disc assembly is pivotable within the fluid passage from an open position wherein the disc assembly is positioned within the fluid passage to provide for free flow of fluid through the fluid passage, to a closed position wherein the disc assembly is positioned within the fluid passage to substantially close off the fluid passage. The disc assembly includes a disc having a circumferential edge having a groove. A seal (e.g., an O-ring) is disposed in the groove. A pressure relief mechanism (e.g., a plurality of apertures) is provided adjacent to the seal to partially relieve differential pressure on the seal caused by fluid passing through the fluid passage. A similar valve having its seal located on the valve body is also provided.