| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a piping structure that can prevent back-flow of discharge water in case of emergency. <P>SOLUTION: In a piping structure 1, a main pipe 81 has a downgrade toward a vacuum station 3 and is connected to it. The piping structure 1 also has a bypass pipe 4 which is formed in the vicinity of the downstream end of the main pipe 81 diverged therefrom and flushes discharge water when a set water head pressure is applied. Then, a relief valve 5, which opens when a set water head pressure is applied, is disposed on the bypass pipe 4. In addition, a plurality of branch pipes 82 diverged from the main pipe 81 and a vacuum valve 2 unit having a vacuum valve 21 to be connected to the branch pipes 82 are further provided. As for a set water head pressure, it is set lower than that of the level at which discharge water is back flowed after the vacuum valve 21 is opened by the set water head pressure of the discharge water reserved in the main pipe 81. <P>COPYRIGHT: (C)2012,JPO&INPIT |
