| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a shutoff device using a bag equipped with a structure to prevent gas from flowing into a working area when an established pipeline especially a high pressure pipeline is being repaired. SOLUTION: This gas shutoff device introduces a bag possible to expand and shrink, at the end part for repair of a pipeline when an established pipeline is repaired. This bag is used to cutoff the flow of gas after it is expanded. The device is provided with a double bag 3 consisting of a first bag 31 and a second bag 32 to be inserted into the inside of a pipeline from a small type communication hole formed at a required end position for repair part in the pipeline, and an air passage 4 consisting of multi-tube structure to expand the first and the second bags 31, 32. The air passage 4 is constructed so that a part of it is connected at least to the inside of the first and the second bags 31, 32 and a space positioned between both bags, respectively.</p> |
