| 摘要 |
PROBLEM TO BE SOLVED: To provide an installation method for a butterfly valve in a constant water construction method capable of simplifying work processes from hole boring to valve insertion, and securely stopping water. SOLUTION: With a boring device installed on a transfer device 4 that is movable in a pipe axis direction of a city water main pipe 1, a butterfly valve inserting hole H and a butterfly valve shaft support hole 50 are formed in the city water main pipe 1. The boring device is then replaced by a butterfly valve inserting device 52 to be installed on the transfer device 4, and the butterfly valve 58, opened, is charged from the butterfly valve inserting hole H. A valve shaft 62 is rotatably supported in the butterfly shaft support hole 50, and the butterfly valve inserting hole H is sealed. Installation work is thus easily conducted. COPYRIGHT: (C)2004,JPO
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