Abstract: A thermally-insulated pipeline for the transportation of a cryogenic liquid, comprising three coaxial pipes formed of sections, one inner pipe made of a material having a low thermal expansion coefficient, a middle pipe and an outer pipe made of steel. The pipes are linked by linking parts which join sections of each respective pipe and take up the loads produced by thermal expansion or contraction when the pipes change temperature. The linking parts that join the inner pipe and the middle pipe are separated from the linking parts that join the middle and outer pipe, so that a thermal bridge cannot form between the inner pipe and the outer pipe.

Abstract: A pipeline for the transportation of a cryogenic liquid, thermally insulated and comprising three coaxial pipes formed of sections, one inner pipe made of a material having a low thermal dilation coefficient, a middle pipe and an outer pipe made of steel, the annulus space between the inner pipe and the middle pipe being provided with thermal insulation, wherein: the pipes are linked two by two using linking parts so as firstly to join the sections of each respective pipe and secondly to take up the loads produced by thermal contraction when the pipes change temperature. the section of the middle pipe is of a sufficient length such that when assembled, in cooperation with the linking parts, it prevents the formation of a thermal bridge between the inner and outer pipes.

Abstract: A pipeline for moving effluents at seabed level, including an inner shell and at least one outer shell having an outer surface separated from the inner shell by an annular space for receiving an insulating layer, wherein the outer shell includes a set of mutually spaced flutings arrayed along at least a portion of the outer surface and each fluting has a bottom resting on a spacer element located around the inner shell.

Abstract: The invention relates to a device reinforcing circumferential welds 8 which join two contiguous pipes 6 and 7 in order to increase the fatigue life of said welds by reducing mechanical stresses in them when being subjected to periodic bending. The device comprises a rigidifying element 10 which is firmly joined to said pipes by a connection means 11, 13, said bush being made of the same material as the pipes. The rigidifying element 10 consists of a bush slipped over the two pipes 6, 7 opposite the weld 8. The connection means is a hardening material 11 such as resin or cement which is injected between bush and pipes and which is confined at this site by shaping, in particular cold-forming, the bush's ends. The application is to offshore hydrocarbon conveyance conduits subjected to periodic loads.

Abstract: A process and machine to make double-walled pipe to be connected end to end, wherein each pipe includes inner and outer tubes arranged coaxially with a ring-shaped space between them except at a connecting area at the end of the pipe where the outer tube is longitudinally retracted with respect to the inner tube. An end-wall of the outer tube is deformed to close off the ring-shaped space by the gradual application of pressure to its wall by means of a series of bars spaced in a ring around a connecting area and tilted over in a radial direction by a crown that is fixed with respect to the outer tube and onto which the bars are attached in an articulated manner.

Abstract: A line pipe with a double casing is especially used in transporting oil products. In a preferred embodiment, such a pipe is characterized in that, in a sealed annular space, located between an inner tube and an outer tube both coaxially arranged inside each other, there is included a self-sustaining plate made of open pore-microporous material, which is flexible enough to be externally wound around the inner tube. This plate is preferably less in thickness than said annular space such that a passageway is left free between the former and the outer tube whereby low pressure is maintained.