Abstract: A coupling for joining socket ends of multilayer tubing through electrofusion including a central body having opposing male ends. A core at least partially surrounds the central body and an outer layer encloses the core and central body. The outer layer defines a flange protruding radially outwardly from the central body, wherein the core includes a portion that extends radially outwardly through the flange and out of the flange so that the core can be directly heated by an external heating element.

Abstract: A tubing assembly including elongated first and second tubes for carrying a fluid flow. Each tube is a composite tube having an inner layer, a middle layer surrounding the inner layer, and an outer layer surrounding the middle layer. At the end of each tube, the tubes are flared outward from an axis of the tubes in complimentary shapes with the middle layer being directed away from the fluid flow and following a contour of the inner layer. The tubing assembly may include a gasket provided intermediate the inner layers. A clamp compresses the ends together and the gasket (if provided) to create a joint between the inner layers of the ends and maintain a seal between the inner layers of the flared ends.

Abstract: A joining method wherein ends of multilayer composite tubing and/or fittings having at least one middle layer of malleable metal are flared radially outwardly so that exposed ends of the middle layer of malleable metal are directed radially outward and away from a fluid flow path within the tubing and/or fittings. The flared-out ends are then fused using infrared butt welding so that the resulting bead protrusion into the fluid flow path is small enough to be acceptable for use in a high purity water system.

Abstract: A saddle wye for connecting a branch pipe to a heat fusible thermoplastic main pipe, including a heat fusible thermoplastic saddle shaped and adapted to be received on the main pipe. The saddle includes top and bottom surfaces and an opening extending between the top and bottom surfaces for alignment with an opening in the main pipe. A branch extension extends at an acute angle from the top surface of the saddle such that a first open end of the branch extension is connected the opening of the saddle and a second open end of the branch extension extends above an end of the saddle. A resistance heating wire is secured to the bottom surface of the saddle around the opening of the saddle in a pattern that includes a parabola. The wire pattern assures that fusion occurs close to the opening in the saddle to prevent fluid from reaching between the saddle and a sidewall of the main pipe as fluid travels between the branch pipe and the main pipe.