Fluid-tight isothermal tank for liquefied gas

In a fluid-tight thermal insulating tank for holding a liquid product, said tank comprising two sets of successive sealing and thermal insulating barriers, a primary set positioned to contact the product contained in the tank and a secondary set located between the primary insulating barrier and an external supporting structure, at least the primary sealing barrier comprising metallic plates having inwardly projecting flanged edges welded together and terminating at the intersection between two walls of the supporting structure in a deformable ring the improvement according to which said ring comprises;

• a composite deformable angle assembly, said angle assembly comprising, a first flange and a second flange, each flange comprising a plurality of generally parallelopipedic shaped modules, a facing surface including a strip of metal connected to and spacing said modules regularly and in a longitudinally juxtaposed arrangement, and connecting means for joining said facing surface of one of said flanges to the facing surface of the other of said flanges at essentially a right angle so that the modules of said one flange bear against the modules of the other said flange;
• and securing means connected between the angle assembly and the external supporting structure for holding said modules against the subjacent insulating barrier.