METHOD OF CONSTRUCTION FOR BRANCHING LIVE PIPE OF CITY GAS PIPING

摘要

PURPOSE:To suppress leakage of gas by using a connecting tool, mounting bed, drilling machine and a valve unit mounting machine at the time of connecting a branch pipe. CONSTITUTION:A city gas pipe 2 is cut off by a drill 8a, in a condition that leakage of gas is suppressed by action of a connecting tool main unit 1, mounting bed 7 and a drilling machine 8, by mounting the mounting bed 7 to the connecting tool 1 and the drilling machine 8 to the mounting bed 7, opening its shutter 7a and by inserting the drill 8a of the drilling machine 8 from a passage 7b of the mounting bed 7. Next, a valve unit mounting machine 9 is mounted to the mounting bed 7, and a valve seat 10 and a valve unit 11 are inserted from the passage 7b of the mounting bed 7 by the similar method and internally fitted in a condition that leakage of gas is impeded by seal members 16a to 16g. Finally, a switching valve, possible to select a steady condition and the first, second and third work conditions, is formed by closing an opening part of the connecting tool 1 by a cover unit 17. In this way, branch piping connection can be not only executed in a condition that a connection condition can be selected by continuing supply of city gas to suppress its leakage but also executed easily, promptly and inexpensively.