Smoke or gas duct, has assembly of tubular units each with male coupling end fitting including tubular portion of section smaller than that of male end fitting`s tubular portion of other unit, where each portion is terminated by end portion

摘要

The duct has a set of tubular units (2, 2`) each with a female coupling end fitting (4) having an extreme tubular section (5) of section larger than that of the unit. Each end fitting is coupled by a truncated connection portion (6) to a tubular section (7) of the unit. A male coupling end fitting (3) of each unit has a tubular portion (8) of section smaller than that of a tubular portion (5) of the end fitting (4) of the other unit. Each portion (8) is terminated by a truncated end portion (9) of the end fitting (3). The portion (9) is supported on the portion (6) under the effect of stress.