| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas interrupting device having a constitution performing sure interruption of gas by making close adhesion capable to a pipe inner surface even when a dimensional difference exists in a pipe internal diameter to prevent generation of passing gas. SOLUTION: This gas interrupting device, using a bag introduced into a pipe line buried in the ground to be made in close adhesion by expansion to a visual road inner surface so as to interrupt circulation of gas, is characterized by forming the above bag in tire shape to provide in its external peripheral part an expansible/contractible deformation margin part and expanding it in a diametric direction independently of a part except this deformation margin part in accordance with an expansion pressure in this bag, so that a part from a shoulder part over to the external peripheral part can change an area abutting to the above pipe line inner surface. |
