A tube body production method includes repeating a fiber layer forming step to form fiber layers so that the fiber layers are disposed in a manner of being stacked in a radial direction of a cylindrical tube member. Each fiber layer forming step includes, to form a current fiber layer: disposing a respective fiber body with respect to an outer circumferential surface of the cylindrical tube member so that the respective fiber body extends in an axial direction of the cylindrical tube member; and winding a respective first fixing member with respect to the outer circumferential surface of the cylindrical tube member such that the respective first fixing member is wound over the respective fiber body by one or more turns in a circumferential direction, along the axial direction of the cylindrical tube member, at a different phase with respect to the first fixing members disposed for other fiber layers.

A tube body production method includes steps of: disposing a fiber body with respect to an outer circumferential surface of a mandrel so that the fiber body extends in an axial direction of the mandrel and an axial direction end portion of the mandrel has an exposed region where the fiber body is not disposed; disposing a fixing member with respect to the outer circumferential surface of the mandrel so that the fixing member covers the fiber body and extends to the exposed region, the fixing member having a tubular shape and configured to fix the fiber body with respect to the outer circumferential surface of the mandrel; and impregnating the fiber body with a resin on the outer circumferential surface of the mandrel and then heating the resin to mold the resin.

Provided is a tube body intermediate including: a carbon fiber disposed with respect to an outer circumferential surface of a mandrel so as to extend in an axial direction of the mandrel; and a fixing member having a tubular shape and disposed with respect to the outer circumferential surface of the mandrel so as to cover the carbon fiber. Also provided is a tube body production method including: disposing a fiber body with respect to an outer circumferential surface of a mandrel so that the fiber body extends in an axial direction of the mandrel; disposing a fixing member with a tubular shape with respect to the outer circumferential surface of the mandrel so that the fixing member covers the fiber body; and impregnating the fiber body with a resin on the outer circumferential surface of the mandrel and then heating the resin to mold the resin.

The tube body intermediate includes: a carbon fiber disposed with respect to an outer circumferential surface of a mandrel such that the carbon fiber extends in an axial direction of the mandrel in a manner of being wound by less than one turn; and a first fixing member wound with respect to an outer circumferential surface of the mandrel such that the first fixing member extends in the axial direction of the mandrel in a manner of being wound over the carbon fiber by one or more turns in a circumferential direction.

The present invention relates to a pipe suitable for conveying fluids in HVACR applications, which pipe comprises an inner tube delimiting an inner space or passageway for a fluid, an insulating cover and an anti-corrosion layer.

A multi-layered pipe including a first polyethylene layer comprising raised temperature (PE-RT) resistance forming a longitudinal axis of the pipe, an ultra-high-molecular-weight polyethylene (UHMWPE) layer disposed around the first PE-RT layer, a second PE-RT layer disposed around the UHMWPE layer, and, optionally, at least one bonding layer disposed between at least one of the respective first or second PE-RT layers and the UHMWPE layer. At least one of the layers comprises a nanoclay material for reducing gas transport through the layers.