| 摘要 |
An inlet shut valve or an outlet shut valve has a main diaphragm and a sub-diaphragm, wherein a valve closing pressure chamber and a valve opening pressure chamber are provided, respectively, on the upper surface side and the lower surface side of the main diaphragm. Furthermore, an atmospheric pressure chamber and a pressure chamber constituting a channel are provided, respectively, on the upper surface side and the lower surface side of the sub-diaphragm. A drive shaft constituting a valve element is driven in the direction for bringing about a valve open state by both forces, i.e. a first force acting by pressure difference between the valve closing pressure chamber and the valve opening pressure chamber and a second force acting by pressure difference between the atmospheric pressure chamber and the pressure chamber constituting a channel and acting in the same direction as the first force. |
