摘要 |
A passage switching valve includes a lower actuator and an upper actuator. the lower actuator includes a case, a diaphragm, an operating rod, and a spring. A lower end of the operating rod is connected to a valve element. The upper actuator includes a case, a diaphragm, an operating rod, and a spring. An upper end of the lower operating rod is abuttable on a lower end of the upper operating rod. The upper pressure chamber and the lower negative pressure chamber are communicated with each other. Each of the negative pressure chambers of the actuators is to be supplied with negative pressure. Each of the operating rods is held against vibration by a bush. The lower spring is set to be greater in urging force than the upper spring.
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