Abstract: A connection between two pipes of a pipeline includes a pair of coupling members having externally threaded ends with sealing surfaces projecting from the ends. The threaded ends are advanced into opposite ends of an insulating sleeve fabricated of electrically nonconductive material. Internally threaded end portions of the sleeve are separated by an annular recessed portion. A resilient, nonconductive annular spacer is retained within the annular recessed portion. The spacer includes a pair of inclined inner sealing surfaces positioned in overlying sealing relation with the coupling member sealing surfaces and an outer sealing surface sealingly engaging the insulating sleeve to form a fluid and pressure tight seal around the annular space between the coupling members and the insulating sleeve in addition to electrically insulating the coupling members from each other.

Abstract: A molded polyethylene valve body has a conduit portion and an annular portion extending upwardly from the conduit portion. A passageway extends through the conduit portion for the conveyance of fluid. A valve seat is formed in the conduit portion by a metal sleeve that is molded in the valve body to prevent separation of the sleeve from the valve body during sustained pressures. O-rings positioned in grooves around the metal sleeve are compressed by the plastic material during the molding process to effect a seal between the sleeve and the plastic valve body. An annular rubber sleeve insert is vulcanized onto the inner diameter portion of the metal sleeve. A plastic valve disc is centrally positioned in the conduit portion within the periphery of the rubber sleeve insert and is arranged to sealingly engage the rubber sleeve insert when the valve is moved to the closed position. A metal stem extends through the annular portion of the valve body and is connected to the valve disc.