| 摘要 |
PROBLEM TO BE SOLVED: To prevent urban sewerage from becoming full, by preventing rainwater from excessively flowing from a rainwater pipe of a house into the sewerage.SOLUTION: A cylindrical connection box 17 extending in the vertical direction is disposed so as to enfold a rainwater pipe 4 divided into an upper pipe 13 and a lower pipe 14. The connection box 17 has its lower end having an inward flange 18 and its upper end, at least part of which is open; the inward flange 18 is fluid-tightly connected to the outer peripheral surface of the lower pipe 14. The inside of the rainwater pipe 4 communicates with the inside of the connection box 17; a space defined by the connection box 17 and the rainwater pipe 4 forms an excess water storage tank 19. A flow rate throttle 24 is provided inside the lower pipe 14. The connection box 17's upper end open part functions as an excess water exhaust port 20. Rainwater controlled using the flow rate throttle 24 is stored in the storage tank 19. When heavy rain has ended, rainwater stored in the storage tank 19 naturally flows out through the flow rate throttle 24.SELECTED DRAWING: Figure 2 |
