| 摘要 |
PURPOSE:To close an air opening in a rapid response against a flow rate of supplied water and reduce an amount of water overflown from the air opening by a method wherein the first check valve and a surrounding air releasing port are opened or closed in a reversible manner and the surrounding air releasing valve is sufficiently small in regard to the valve body. CONSTITUTION:The first check valve 10 is constructed such that a plunger 14 having a partition plate 13 is disposed in a valve chamber wall 11 and an upper valve chamber 12. An upper part of the plunger 14 is provided with a seal member 15 for opening or closing an inlet port 4 acting as a connection part with a feeding pipe 3, and then a surrounding air releasing port 11A is opened or closed by a surrounding air releasing valve 16 disposed at a lower end of the plunger 14. In this case, the surrounding air releasing valve 16 is set sufficiently small as compared with the partition plate 13 installed in the plunger 14. The inlet port 4 and the surrounding air releasing port 11A are closed to each other in a reversible manner and in the event that one of them is closed, the other is always released. However, in the event that a flow rate of water flowing from the inlet port 4 is less in its volume, the inlet port 4 and the surrounding air releasing port 11A are released to open together. |
