| 摘要 |
<p>PURPOSE:To prevent take fire to gas in a gas flow pipe at welding time without executing a nitrogen gas injecting process, by performing welding a fillet cap against a cut end part of the gas flow pipe in a condition that inside the gas flow pipe is exhausted further to seal an outflow of gas in the gas flow pipe by a heat resistant seal member. CONSTITUTION:In the case of fixedly welding a fillet cap 4 in the cut end part periphery of a steel pipe-made main pipe 1, a diffusion pipe 2 is connected to the main pipe 1, to insert a rubber ball 3 (3a, 3b) into the main pipe 1 from this diffusion pipe 2. In a condition that each rubber ball 3 is inflated to temporarily close the main pipe 1, a heat resistant seal member 11 is interposed between itself and a cut end face 1d, to fit a fillet cap 4 to the cut end part periphery. Next by using screw bars 8... and nuts 9... equally arranged in a circumferential direction relating to a fixe band 7 fixed to the cut end part periphery, the cap 4 is uniformly pressed to the cut end face 1d by a pressing plate 10. Thereafter, the temporarily closed condition by the rubber ball 3 is released to exhaust air in the pipe, and the cap 4 is welded to the main pipe 1.</p> |
