Abstract: A process for preimpregnating reinforcing elements with a liquid substance includes the following series of steps or stages: placing the reinforcing elements in a sealable enclosure, applying a vacuum of sufficient intensity and duration to the enclosure to eliminate at least the majority of water and gas present in the reinforcing elements contained therein and introducing sufficient liquid substance into the enclosure for the substance to cover the elements once the elements have been impregnated. The device for carrying out this process includes an enclosure for containing the elements, means for applying a vacuum to the enclosure for removing at least the majority of the water and gas present in the reinforcing elements and an orifice or conduit for introducing the liquid substance into the enclosure.

Abstract: The invention provides a coupling and a method of manufacturing such a coupling for a shaft having at least one free traction resistant reinforcement framework, said drawn, wedge or plugged coupling including, in the immediate vicinity of the anchorage means, free threads of the tractive force resistant framework and an elastomer cushion through which the threads pass, said cushion increasing the resistance of the couplings and allowing a better use of the shafts.

Abstract: A tubular structure is provided including an internal tube and an external tube which is formed from at least a straight strip bent or undulated, whose width is disposed substantially along at least a line normal to said tubes which it separates. It may be used, for example filled with an insulating lagging, by surrounding a pipe line or being adapted to the pipe line which then forms the internal tube.