Rainwater drainage piping structure

摘要

PROBLEM TO BE SOLVED: To stably merge drainage from a branch pipe to a main pipe at a confluence portion provided on an intermediate floor when draining rainwater from an upper floor to a lower floor by applying a siphon phenomenon. The purpose is to provide a rainwater drainage pipe structure. SOLUTION: A siphon type drainage member arranged on an upper floor, a main pipe 122 in which rainwater flowing in from the siphon type drainage member flows down from the upper floor to the lower floor, and a main pipe 122 in the middle in the height direction. A rainwater drainage pipe structure 100 including a branch pipe 150 connected to a located merging portion 120T and allowing drainage to flow into the merging portion 120T from the outside, and a diameter-reduced portion 131 provided at the merging portion 120T. [Selection diagram] Fig. 5