Abstract: Method for manufacturing, and heat-insulated pipes comprising coaxial tubes sliding relative to each other with controlled friction: (a) applying a film (3) of non-adhesive and lubricating material onto the inner surface of a first outer casing tube (2) and/or onto the outer surface of a second inner carrier tube (1); b) fixing a series of spacers (4) made of heat-insulating material onto the inner carrier tube (1); c) coupling and centring the outer casing tube (2) on the inner carrier tube (1); d) mounting suitable sealing flanges (6) on the ends of said tubes (1, 2) coupled together; f) supplying, via the flange or flanges (6) and by suitable means (7), liquid resin which, as a result of subsequent expansion, fills completely the cavity (5) formed between said tubes (1, 2); g) removing the flanges.

Abstract: Method for the implementation in situ of the three-layer coating with thermoplastic materials for the anticorrosive protection of welding joints of coated metal pipes, and/or of damaged coating areas, by wrapping up a ready-to use sheathing/band or tape, made of thermoplastic materials. The application of the sheathing/band or of the tape onto the joint is carried out mechanically by means of a suitable roll, e.g. in silicone rubber, said roll, carried by a suitable device placed on the pipe in the area to be coated, turning around the pipe wrapping and pressing with the desired pressure the sheathing/band/tape onto the pipe itself and ensuring a strong adherence to the support/pipe and the absence of air bubbles entrapped between the sheathing/tape and the pipe.