Abstract: A coupling is provided for joining segments of plastic pipe. The coupling includes a body portion having an inner bore opening to an enlarged outer bore. A metal stiffener tube having a flange at one end is inserted into the bore of the body until the flange contacts an internal stop. An elastomeric gasket encircles the stiffener. A flexible spring washer encircles the stiffener and contacts the outside end of the gasket. A grip ring, comprising a frustoconical radially outer surface, an inner surface with gripping members, a segmented lateral slot, and a resilient lip around one end, encircles the stiffener so that the lip is in contact with the spring washer. A connecting nut having a frustoconical bore for mating with the outside surface of the grip ring surrounds the stiffener and engages the enlarged bore of the body. The plastic pipe is inserted into the bore and around the stiffener.

Abstract: A service valve includes a valve body (12) having an upper chamber (18), a lower chamber (20), an open top end (22) and an open bottom end (24). The lower chamber (20) includes an inlet opening (26) and an outlet opening (28). A valve member (14) is disposed in the valve body (12) and is molded of plastic material to form a unitary body including a plug portion (36) having a flow passage (38) therethrough and an actuator portion (34). The plug portion (36) is rotatable in the valve body (12) between an open position where the flow passage (38) is aligned with the inlet (26) and outlet (28) openings and a closed position where the flow passage (38) is out of alignment with the inlet (26) and outlet (28) openings. The actuator portion (34) extends outwardly from the plug portion (36) through one of the chambers (18, 20). First ( 50) and second (51) seals act between the plug portion (36) and the valve body (12) for sealing against leakage from the inlet opening (26) and outlet opening (28).

Abstract: A plastic service valve includes a valve body of molded plastic having upper and lower chambers. The valve body is open at the top and bottom ends. The lower chamber includes inlet and outlet openings. A thrust seat is formed within the upper chamber between the open top end and the inlet and outlet openings in the lower chamber. A valve member is disposed in the valve body and positioned against the thrust seat. Structure is provided in the valve member and adjacent to the thrust seat for locking the valve member to the valve body. The valve member is molded of plastic material to form a unitary body including a plug portion and an actuator portion. The plug portion is rotatable in the valve body between an open position which is aligned with the inlet and outlet openings of the lower chamber of the valve body and a closed position. The actuator portion extends upwardly through the upper chamber portion and receives an operating nut.

Abstract: A stop changer tool for removal of an in-service valve under pressure and comprised of a displaceable shaft assembly supporting at one end an axially compressible elastomeric plug adapted to be inserted through the valve into the upstream pipe. The plug is mounted between a pair of restraining ends such that displacing the shaft assembly in a withdrawal direction draws the restraining ends toward each other to compress and diametrically enlarge the plug until a pressure sealing engagement is achieved with the pipe surface thereat. The restraining ends are formed of laterally displaceable contiguous elements having predetermined face angles on opposing surfaces whereby they are relatively displaced laterally outward concomitantly with compression of the plug so as to substantially restrain the plug against axial extrusion.

Abstract: A valve, such as a butterfly valve having an offset closure vane and a thru shaft for operating the vane in the flow passage of the body, has all exposed and/or potentially vulnerable metal surfaces encapsulated in a corrosion resistant polymeric plastic coating. By extending the coating uninterrupted from the flow passage through the shaft bore and sizing the bore coating to within controlled tolerances, overall corrosion protection of the valve is substantially enhanced while enabling the coating per se to function as a bearing surface for the operator shaft.