Abstract: An elastomeric sleeve is placed under axial compression in a pinch valve assembly. The axial compression of the sleeve eliminates any crevices with end members that engage opposed end walls of the valve body. Further, axial compression extends cycle life of the valve by maintaining the sleeve in a non-tensile relationship. Mechanical gripping of enlarged flanges defined at opposed ends of the sleeve is also enhanced through axial compression of the sleeve. A positive, visual indication of valve open and closed positions is provided by an indicator stem extending outwardly from an actuator body. In an alternate embodiment, the flanges are reinforced. Additionally, a casting member is interposed between the valve body and sleeve for ease of replacement and maintenance. In still another embodiment, a vent opening in the valve body eliminates pneumatic closure forces on the elastomeric sleeve that can arise when the pinch valve is heated.

Abstract: A new packing arrangement is provided for improved sealing and limiting potential for extrusion of one packing member relative to another. The stem packing arrangement is disclosed with particular reference to a ball valve assembly having a body housing a selectively rotatable valve member. An actuating stem extends from the body through a stem passage and the packing assembly is received in the passage around a portion of the stem. First, second, third, and fourth members progressively increase in hardness to limit extrusion of one member relative to another. A predetermined compression is also applied to the packing assembly and is independent of the actuating stem so that bearing member life is increased. The second member includes a tapered external surface that cooperates with the stem passage to provide a wedging action along the inner and outer diameter portions thereof.

Abstract: An elastomeric sleeve is placed under axial compression in a pinch valve assembly. The axial compression of the sleeve eliminates any crevices with end members that engage opposed end walls of the valve body. Further, axial compression extends cycle life of the valve by maintaining the sleeve in a non-tensile relationship. Mechanical gripping of enlarged flanges defined at opposed ends of the sleeve is also enhanced through axial compression of the sleeve. A positive, visual indication of valve open and closed positions is provided by an indicator stem extending outwardly from an actuator body. In an alternate embodiment, the flanges are reinforced. Additionally, a casing member is interposed between the valve body and sleeve for ease of replacement and maintenance. In still another embodiment, a vent opening in the valve body eliminates pneumatic closure forces on the elastomeric sleeve that can arise when the pinch valve is heated.

Abstract: An elastomeric sleeve is placed under axial compression in a pinch valve assembly. The axial compression of the sleeve eliminates any crevices with end members that engage opposed end walls of the valve body. Further, axial compression extends cycle life of the valve by maintaining the sleeve in a non-tensile relationship. Mechanical gripping between enlarged flanges defined at opposed ends of the sleeve is also enhanced through axial compression of the sleeve. A positive, visual indication of valve open and closed positions is provided by an indicator stem extending outwardly from an actuator body.