double joint

OBS: Joint: Zone de liaison entre lés, nappes (ou panneaux),
OBS: Double soudure: Modalité d'assemblage comportant la réalisation simultanée de deux joints parallèles, effectués en soudure automatique et séparés par une zone non soudée. Ce canal central sert généralement à faire des tests d'étanchéité du joint, sous pression

CONT: The pressurized dual seam [testing] method was mentioned earlier in connection with the double-wedge thermal seam method. The air channel that results between the double seam is inflated to approximately 30 lb/in[superscript 2] for 100 to 200 ft. If no drop in pressure occurs, the seam is acceptable; ...
OBS: The hot wedge or hot knife method consists of an electronically heated resistance element in the shape of a blade that is passed between the two sheets to be sealed. As it melts the surfaces, roller pressure is applied. An interesting variation is the dual-hot-wedge method, which forms two parallel seams with an unbonded space between them. This space is subsequently pressurized with air and any lowering of pressure signifies a leak in the seam