Abstract: A sintered metal body, having an annular form suitable for use as a valve seat or seal, is impregnated with an uncured polymeric material such as PTFE which is then cured to partially fill the interparticulate spaces in the sintered metal body. The impregnated body is then subjected to applied pressure which preserves the annular shape of the body while collapsing substantially all voids throughout the body to cause the cured polymeric material within the sintered metal body to completely fill the collapsed interparticulate spaces thereby to render the body nonporous throughout.Inasmuch as the interparticulate spaces are completely filled with cured polymeric material, any increases in temperature of the body which result in an expansion of the polymeric material cause a migration of portions of that material from the interior of the body to the exterior surfaces of the body to lubricate the exterior surfaces.

Abstract: A valve, such as a ball valve of known configuration, is provided with an elongated housing which has an open end the internal diameter of which is sufficiently large to permit the insertion of a ball valve member into the housing during assembly of the valve. The open end of the housing is internally threaded and receives a hollow cylindrical externally threaded end plug which is screwed into the open end of the housing following insertion of the ball to retain the ball in place within the housing. The end plug is provided with a plurality of notches that are spaced from one another about the end plug axis, and, after the valve has been completely assembled, portions of the housing adjacent the said open end are deformed to provide locking tabs which extend into the end plug notches to prevent rotation of the end plug.

Abstract: A shoe has a first coupling element secured on a heel portion thereof and a second coupling element, defining a heel thereon, is slidably mounted in interlocking relationship on the first coupling element. A resilient locking tab on the second coupling element engages a locking groove formed on the first coupling element and is held in locked relationship therein by a removable wedge.

Abstract: A pneumatic valve actuator having a rotatable output shaft is provided with a valve positioner comprising an axially displaceable spool valve and a pneumatic transducer responsive to applied signal air pressure for displacing the spool valve away from a neutral position to effect rotation of the actuator output shaft. The actuator output shaft is gear-connected to an element which rotates with the output shaft, and an elongated cantilever beam spring attached at one end to the rotatable element extends in a direction transverse to the axis of rotation of said element to the transducer for providing a feedback force which balances the control signal responsive transducer force when the actuator output shaft has rotated to a desired position.