| 摘要 |
PURPOSE:To prevent an unnecessary jump of a valve plate even if wavy vibration is caused by in gas pressure by incorporating the valve plate having a through hole at the center thereof in a valve chamber communicating with a gas inflow path and pressing the valve plate to valve seats of the inflow path and an outflow path with abnormal pressure. CONSTITUTION:When the upstream side 12a of a gas passage 12 is connected to a gas pipe, the downstream side 12b thereof being connected to a gas appliance, and a closer 13 is located at an open position so that gas flows normally, a valve plate 8 is lowered to the open position, so that gas flows through the upstream side 12a of the gas passage, an inflow path 2, a valve chamber 4, an outflow path 3 and through holes 16, 12 of the closer 13. In case of an abnormal outflow, the gas pressure of the valve chamber 4, the outflow path 3 and the downstream side 12b is lowered so as to decrease the pressure of gas flow flowing from the inflow path 2 to the valve chamber 4 to the valve plate 8 surface, and at the same time, the gas pressure blown in through a through hole 9 to the back of the valve plate 8 pushes up the valve plate 8 to be pressed to valve seats 5, 6, thereby intercept outflow of gas. When an abnormal outflow is removed, and the closer 13 is closed, the valve plate 8 is lowered. |
