| 摘要 |
PURPOSE: A drain flowing backward preventing apparatus of a manhole is provided to prevent order from the drain and discharge waste water flowed in through an inlet tube. CONSTITUTION: A drain flowing backward preventing apparatus of a manhole comprises a subsidiary space(20), a flexible pipe(30) and a buoy(40). The subsidiary space is located between a drainpipe(12) and the manhole and connected to the manhole. The flexible pipe is connected to the drainpipe and has one end connected to the drainpipe and the other end fixed to the manhole. The buoy is combined at the middle part of the flexible pipe and has a hollow inside. |
