| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device of a vacuum valve, which can prevent the vacuum valve from being damaged under the pressure of sewage even if the level of the sewage rises excessively and which is used in a vacuum sewage collecting system.SOLUTION: This control device of a vacuum valve includes vacuum valve opening/closing mechanisms 64, 65, 53, 70a for changing over between vacuum and atmospheric pressure supplied for opening and closing the vacuum valve 4, a reciprocatable shaft 54 for operating the vacuum valve opening/closing mechanisms, a spring 68 for pressing the shaft 54 in the direction in which the vacuum valve 4 is closed, a first diaphragm 56 and a second diaphragm 59 reciprocatable integrally with the shaft 54, a first chamber 57 and a second chamber 58 for moving the shaft 54 in the direction in which the vacuum valve 4 is opened by causing a differential pressure between both sides of the first diaphragm 56, a third chamber 60 and a fourth chamber 61 for moving the shaft 54 in the direction in which the vacuum valve 4 is opened by producing a differential pressure between both sides of the second diaphragm 59, and a displacement restricting mechanism 78 for restricting the displacement of the shaft 54 in the direction in which the vacuum valve 4 is closed. |
