MANUFACTURE OF PIPE HAVING FLANGE

摘要

PROBLEM TO BE SOLVED: To enhance the fatigue strength at the connecting part between a flange and pipe with simple working, high productibity inexpensively. SOLUTION: A reinforcing pipe 2 having the outer diameter smaller than the inner diameter of a main pipe 1 is inserted into the end of the main pipe 1 where the flange 3 is welded, the reinforcing pipe 2 is flared together with the main pipe 1 using a flaring tool, whereby the reinforcing pipe 2 is tightly brought into contact with the main pipe 1.