Branch, drainage piping structure having the same, connection method of branch pipe

摘要

PROBLEM TO BE SOLVED: To provide a branch pipe allowing a main pipe to be easily connected to a fitting pipe when replacing an already constructed main pipe with a new main pipe, a drain piping structure provided therewith, and a method for connecting the branch pipe.SOLUTION: A branch pipe 30 connects a main pipe 10 to a fitting pipe. The branch pipe 30 includes a flange plate 60 in which a hole 62 is formed and a tubular body 40. The tubular body 40 includes: a first opening 50 connected to the outer peripheral part of the hole 62 of the flange plate 60; a second opening 55 having an opening surface 57 connected with the fitting pipe; and a cylindrical part 43 connecting the first opening 50 and the second opening 55 together and formed in a cylindrical shape. A cross-section of the flange plate 60 has a shape along a circumferential direction A1 of the main pipe 10. An axis line L2 of the second opening 55 and a direction B1 orthogonal to the cross section of the flange plate 60 are substantially parallel.