PIPING CONNECTING METHOD, PIPE EXPANDING TOOL, AND PIPE EXPANDING METHOD USING PIPE EXPANDING TOOL

摘要

PROBLEM TO BE SOLVED: To provide a piping connection method reducing a burden at the time of connection work, with no joint required when connecting piping.SOLUTION: The piping connection method includes: a closing step in which an open end of a first piping 10a, among two pipings, is closed while an open end of a second piping 10b is partially closed; a pipe expanding step in which a connection end of the first piping 10a is expanded and a part of the expanded connection end is enlarged outward beyond other portion, to form a partially expanded pipe part 22; an assembling step for inserting a connection end of a second piping 10b into the connection end of the first piping 10a that has been enlarged; a gas substitution step in which a combustion gas is caused to flow from a partially enlarged pipe part 22 toward the open end of the first piping 10a while the air in the piping is exhausted from the open end of the second piping 10b that has been partially closed; and a brazing step for filling a gap between the connection end of the first piping 10a and the connection end of the second piping 10b after completion of the gas substitution step.