Abstract: A multi-ring gasket (140) is for sealing the joint between two flanged general non-metallic pipes. In one embodiment, the gasket has an inner ring (72) an outer ring (132) and a plurality of spokes (77) connecting the inner ring (72) to the outer ring (132). The various gasket embodiments have additional features, including having a substantially in-set outermost ring (132) so that the gasket (140) may be used with a flange having a mating surface interior of the bolts employed to draw the flanges together; having spokes (96) that do not encircle the bolts but that provide for aligning the gasket with respect to the bolts and the flanges; having an outer periphery (102) that is at least partially rectilinear; having one or more peripheral notches (112) for receiving a thickness gauge; and having a tab (144) for manipulating the gasket (140) in the installation thereof.

Abstract: A gasket having centering features. The gasket comprises a centering portion for which three embodiments are described. The centering portion is switchable between a flush configuration, in which the gasket may be employed between the flange faces of two pipe flanges as typical, and a centering configuration, in which the gasket provides a means for centering the gasket in the pipe joint. In a first embodiment, a normally flush centering portion comprises a flap for centering the gasket, in a second embodiment, the centering portion comprises a collapsible protuberance for centering the gasket, in a third embodiment, the gasket comprises a non-collapsible protuberance for centering the gasket which is physically removable, and in a fourth embodiment the centering portion comprises an annular ring adapted for mating with an annular relief formed in a corresponding one of the flange faces.

Abstract: A method and apparatus for adjusting torque in an electric impact torque wrench. A current sensing circuit passes current through a power relay for powering an electric impact torque wrench. The power relay is normally in a conducting state. The current sensing circuit includes a threshold current indicator which is activated when current flowing through the current sensing circuit reaches a predetermined threshold amount. The threshold current indicator is provided to a first timer which counts an activation-off time since the threshold indicator is activated, the first timer presuming that the current has remained above the predetermined threshold amount during this time. At the conclusion of the activation-off time, the first timer signals a time-off extender circuit.

Abstract: A multi-ring gasket (24) and flanged pipe joint assembly employing such gasket. The gasket (24) for sealing the joint between two flanged pipes of polyvinylchloride, chlorinated polyvinylchloride or fiberglass-reinforced plastic pipe is provided. The gasket (24) has an inner ring (26), an outer ring (28) and a plurality of spokes (30) connecting the inner ring (26) to the outer ring (28). Voids (34), or reduced thickness areas, are formed between the inner ring, the outer ring and the spokes so as to leave substantial space between the flanges at the voids and thereby reduce the uneven distribution of stress on the flanges when the gasket (24) is installed. The joint assembly employing such gasket (24) has a groove (50) disposed in an inside surface of a flange (12 or 16) and has a channel (51) disposed through the flange. The channel (51) is in communication with the groove (50) and, by means of a port (56), an outside surface of the flange.

Abstract: A joint assembly for a pipe and a backing mechanism therefor. The joint assembly provides for sealing a pipe, the pipe having an elongate axis, an inside surface, an outside surface and a flange disposed at one end thereof, the flange having a front surface facing away from the pipe, a back surface and an inner periphery defining an outlet of the pipe. Sealing material is disposed adjacent the front surface and inner periphery of the flange. A backing member is adapted to engage the flange and to apply a compressive load from the back surface of the flange toward the sealing material adjacent the from surface and the inner periphery of the flange so as to seat the sealing material along the inner periphery. Seating is against a surface of a cooperating joint member adjacent the front surface of said flange.