| 摘要 |
PURPOSE:To obviate a backflow of water in a reservoir in time of the failure of water supply from a water main, by indirectly coupling the water service main with a feed water pipe extending as far as the surface of water in the reservoir via a feed water part capable of pooling water at a higher position than the reservoir surface. CONSTITUTION:When water inside a reservoir is kept constant, a water level inside a detecting part 20 is as well constant and thereby a main valve 12 is in a state of being fully closed. However, when the water level inside the reservoir drops to some extent, a float 6 comes down whereby water inside the detecting part 20 drops into a pipe 5 and a float 24 therefore goes down, so that feed water from a water injection pipe 17 gets started as the main valve 12 comes fully opened. The water level inside the reservoir goes up and water enters the within of the pipe 5, lifting the float 6, whereby the water level inside the detecting part rises, then the float 24 moves upward; thus the main valve 12 is fully closed. |
