Societe Anonyme Dite: Stein Industrie

Maurice Duhamel

Paul Belleride

A device for forming a closed chamber inside a set of two metal pieces of pipework (1) to be interconnected by arc welding under a protective gas, the device comprising a first hollow element made of elastomer disposed inside the first piece of pipework and a second hollow element made of elastomer disposed inside the second piece of pipework, both hollow elements being inflatable to close the corresponding piece of pipework. Each of the hollow elastomer elements comprises a toroidal inflatable tube (2) having a disk (3) fixed to the internal equatorial meridian thereof by gluing, said disk withstanding the pressure difference between the ambient atmosphere and the desired internal pressure inside the closed chamber, said disk being of a proper diameter necessary to cause the zone of the inflatable tube adjacent to said internal equatorial meridian to be concave.

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Toufflers, France

Maurice Duhamel