A coupling piece for an outer end of a multilayered conduit, includes a coupling pipe which is provided on the outer side with a radially upright wall, wherein the wall is widened in an axial direction at a radial distance from the outer side of the body. The outer side of the coupling pipe, the upright wall and the widened portion enclose an annular insertion space into which the outer end of the conduit can be directly inserted, wherein the inner wall of the coupling pipe is reinforced with an adjacent reinforcing layer which has a greater strength than the material of the coupling pipe. The reinforcing layer is provided with axial engaging elements, while the inner wall is provided with axial connecting elements which correspond with and connect to the engaging elements.

Ducting and/or duct couplings can be formed from shape memory polymer material, with the material for example being additively manufactured. The use of shape memory polymer material for one or more of the duct portions may allow for easier installation of the ducting, for example allowing the ducting to be warped and/or bent to fit into or through places that are hard to reach or hard to maneuver through, with the ducting then heated to cause it to return to a predetermined memory shape. The coupling of duct portions together may be accomplished by the duct portions including a shape memory polymer material, with for example ends of the duct portions fitted together, and then heated to use a shape memory property of the material to effect coupling. Heating of the shape memory polymer material also softens the material, allowing it to move to a previously set shape.

A method of heat welding a length of pipe with a coupling is disclosed. The coupling and the length of pipe are of a thermoplastic material. The method includes preparing a first end of the length of pipe; preparing a first groove of the coupling, wherein the first groove is configured to mechanically interface to an inner diameter (ID) and outer diameter (OD) of the length of pipe; heating the first and the first groove to a weldable temperature; joining the first end to the first groove; and permitting the first end and the first groove to cool sufficiently long to form a thermoplastic weld.

A system comprising a pipe and at least one fitting, wherein the pipe is made essentially of a thermoplastic, fiber-reinforced composite material, and the fitting is made essentially of titanium or a titanium alloy, and the pipe and the fitting are connected in a fluid-tight manner

The present disclosure provides a welded body having a connecting structure formed by welding a first molded body and a second molded body, wherein the first and second molded bodies contain at least one copolymer selected from the group consisting of a tetrafluoroethylene/fluoro (alkyl vinyl ether) copolymer and a tetrafluoroethylene/hexafluoropropylene copolymer, and wherein the connecting structure has a liquid contact surface to be in contact with a liquid having a solubility parameter of 14 to 35 (MPa).sup.1/2, a welded part formed in the connecting structure is not exposed to the liquid contact surface, and the number of particles of 30 nm or larger to be eluted from the liquid contact surface in the connecting structure is 1,000 particles/ml or less.