Abstract: A recirculation valve for cooling a centrifugal pump. The invention comprises a valve casing having a first chamber for connection to a centrifugal pump and a second chamber for connection to a fluid outlet, a recirculation port for redirecting fluid from the first chamber to the centrifugal pump. Between the first and second chambers is a check valve means for permitting fluid flow from the first to the second chamber. Connected to the check valve means is a hollow cylindrical valve stem permitting flow from the first chamber to the second chamber. The check valve means is comprised of a circular disc which opens when the fluid pressure in the first chamber exceeds the fluid pressure in the second chamber and closes when the fluid pressure in the second chamber approaches that in the first and intermediate chambers. A two angle control surface between the check valve disc and the valve casing controls the position of the check valve relative to the flow of fluid past the valve.

Abstract: A groove in one of a pair of members to be associated in a sealed connection receives a flexible seal having one end projecting through the opening of the groove for sealing engagement with the other member. An intermediate portion of the seal is sinuous-like in shape whereby upon being subjected to pressure from one side it is urged toward a straightened condition to increase the sealing engagement. In one construction of the invention, the sealing end of the seal has an enlarged head which provides a widened sealing surface and also insures against blowout. Fluid escape ports are provided in the sealing end to prevent pressure build-up on the low pressure side of the seal. The side walls of the seal-containing groove may be substantially parallel in one embodiment and in another embodiment may have a contour assuming roughly the shape of the sinuous-like seal portion.

Abstract: A lined gate valve having a seat proportioned such that the ratio of the unit bearing stress to the unit shear stress is substantially 0.68. In one form of the valve, the seat comprises a plastic ring having an embedded metal band. The seat is removable and is held in place by the end pressure of a pipe flange. The seat can be removed by tapping against the seat in an axially outward direction. In another form of the valve, the seat is integral but has the same proportions as above recited.

Abstract: A rotary ball valve includes a seat support integral with the valve body, a rotatable ball, a movable seat support, a retaining ring, and, on opposite sides of the ball, thin annular seating rings made from a material, such as tetrafluoroethylene. When the valve is assembled, the seating rings are deformed to engage the ball and supports and undergo a small amount of cold-flow outwardly toward interior passage walls of the valve body so that the outer periphery of the seat rings engages and forms a seal between the ball member and the interior passage wall. The seat-engaging surfaces of the seat supports each have grooves into which the seating rings cold-flow during valve assembly. Ribs are thus formed on the seating rings which keep the seats from rocking. The valve also provides an improved stem seal, including a Belleville washer confining a tetrafluoroethylene washer. In addition, the valve includes a handle having a novel projection for limiting movement of the ball to 90.degree.

Abstract: A rotary ball valve includes a seat support integral with the valve body, a rotatable ball, a movable seat support, a retaining ring, and, on opposite sides of the ball, thin annular seating rings made from a material, such as tetrafluoroethylene. When the valve is assembled, the seating rings are deformed to engage the ball and supports and undergo a small amount of cold-flow outwardly toward interior passage walls of the valve body so that the outer periphery of the seat rings engages and forms a seal between the ball member and the interior passage wall. The seat-engaging surfaces of the seat supports each have grooves into which the seating rings cold-flow during valve assembly. Ribs are thus formed on the seating rings which keep the seats from rocking. The valve also provides an improved stem seal, including a Belleville washer confining a tetrafluoroethylene washer. In addition, the valve includes a handle having a novel projection for limiting movement of the ball to 90.degree.