THERMALLY INSULATING PIPE ELEMENTS USED UNDER THERMAL, HYDROSTATICAL AND MECHANICAL STRESSES, AND PROCESS FOR REALIZING SUCH INSULATING ELEMENTS

摘要

1. A thermal insulation system for undersea pipelines subjected to high thermal, hydrostatic, and mechanical stresses, the system comprising, in combination : a metal tube ; a first layer of elastomer surrounding said tube, thereby providing it with anti-corrosion protection ; thermal insulation means comprising a plurality of sectors of layers of cellular insulating material containing air and capable of with-standing hydrostatic pressures, said sectors or layers being bonded to one another by sheets or layers of elastomer that have been vulcanized at a temperature of not more than 120 degrees C, said means being superposed in continuous manner over the first above-mentioned layer ; a second layer of seawater-proof elastomer which resists abrasion and which surround the thermal insulation means ; said layers and insulation means protecting each metal tube of a pipeline except at the ends of each tube, which ends are left without protection in order to enable adjacent tubes to be welded together end-to-end ; and rapid waterproof caulking means for joining together the insulation systems on two adjacent tubes, characterized in that each tube (11) or length of pipeline includes a sleeve (26, 27) at at least one of its ends, and preferably at both ends, said sleeve being made of a material having good characteristics of resistance to corrosion and being interposed between the outside surface (17) of the tube and said first anti-corrosion layer (18) and being put into place while said tube or length is being prefabricated in a factory, said sleeve (26, 27) being covered only in part by the layer (18) of elastomer material.