An internal boss can have an outer side surface shaped to match the bored opening of the DWV pipe, an inner side surface shaped to align with an interior pipe surface of the sanitary Tee or Wye fitting component, and an internal face surface of the boss extending between the side surfaces and shaped to align with an interior pipe surface of the DWV pipe when welded thereto. Snap-fit wings can hold the interior face surface of the sanitary Tee or Wye fitting component against an exterior face surface of the DWV pipe while the fitting component and DWV pipe are homogeneously weldable into a single DWV fitting using a solvent mixture including a common plastic material. Related methods and single homogeneous fittings are also provided.

The polymeric pipes reinforced with a metal casing are used for transporting oil and gas, acids, alkali products, drinking water and industrial water, and also in the transportation of aggressive and neutral pulps. A metal-containing polymeric reinforced pipe includes a welded metal casing and a polymeric matrix having an amorphous-phase-based molecular structure. The metal-containing polymeric reinforced pipe is produced by extrusion moulding with simultaneous feeding of a polymer melt and the reinforcing metal casing into the mould cavity, followed by intensive cooling of the internal and external surfaces of the pipe being moulded. The invention increases the quality and endurance limit in the radial direction of the metal-containing polymeric reinforced pipe, productivity of the process for manufacturing the pipe, and also the strength and technological effectiveness of a pipeline constructed from the pipes produced.

A fitting (1) of weldable, thermoplastic material of a modular structure, comprising a number of elements (2, 3, 9, 10, 11, 12), at least one main element (2, 9) and at least one connecting element (3, 10, 11, 12), characterized in that the elements (2, 3, 9, 10, 11, 12) have end faces (4, 5) at right angles to the center axis (8), and the elements (2, 3, 9, 10, 11, 12) are welded to one another exclusively at the end faces (4, 5).