Abstract: A heat exchanger includes two mutually isolated fluid circuits in close thermal contact, a first fluid circuit, or bundle (3), consisting of a helical winding of two walls and the second circuit consisting of a chamber containing the bundle (3), each circuit including its own fluid input and output elements. The heat exchanger is characterized in that the bundle is elastically deformable under the effect of excess pressure or low pressure.

Abstract: The invention concerns a spiral heat exchanger, consisting of a series of spiral plates spaced apart from one another by spacer elements (3), wherein the spiral plates are formed by a coiled flattened tubular element and consisting of at least a sheet of material (1) whereof the edges (1a, 2b) are sealingly assembled by linking elements (4) which extend parallel to the longitudinal axis (yy?) of the sheet (1). The exchanger is characterized in that the flattened tubular element comprises on its outer surfaces ribs (3) inclined relative to its transverse axis (xx?).

Abstract: The invention concerns a spiral heat exchanger, consisting of a series of spiral plates spaced apart from one another by spacer elements (3), wherein the spiral plates are formed by a coiled flattened tubular element and consisting of at least a sheet of material (1) whereof the edges (1a, 2b) are sealingly assembled by linking means (4) which extend parallel to the longitudinal axis (yy′) of the sheet (1). Said exchanger is characterized in that the flattened tubular element comprises on its outer surfaces ribs (3) inclined relative to its transverse axis (xx′).

Abstract: A casing is cemented within a well bore (P) or pipe by means of a radially expandable tubular preform (1). For this purpose, a) folded preform (1) is inserted into the well (P) or pipe down to the required level; b) the well is sealed off at the bottom of the preform (10 by means of an inflatable hydraulic retainer (4); c) a curable fluid cement is injected onto the retainer so that it surrounds the lower portion of the preform; d) the preform is gradually unfolded from the top towards the bottom to press the cement against the wall of the well or pipe along the full length of the preform; e) the preform is cured to form a casing while the cement is allowed to set; and f) the retainer (4) is deflated and withdrawn from the well or pipe.

Abstract: The tubular structure comprises at least a braid of flexible strands (10) comprising fibers (100) that cross over with a certain amount of play so that the structure is capable of expanding radially while shrinking axially when pressure is applied to the inside of the preform or the matrix.

Abstract: To seal the connection between an internal lining and external borehole, casing or pipeline, one or more elastically deformable annular seals are placed on the preform in a contracted state, in a configuration which does not impede insertion of the preform into the borehole, casing or pipeline. During expansion of the preform the seal itself forms an annular groove for receiving it in the exterior surface of the preform. After hardening of the preform a rigid lining is obtained having an integral seal. Applications include repair of boreholes, casings, especially in oil wells, or pipelines, by internal lining.

Abstract: In the automatic positioning of one submerged unit relative to another submerged unit without the use of guide lines, guiding structures associated with the units are brought into contact and the units are relatively orientated before the units are brought into contact.