| 摘要 |
The valve has a body (7) that includes inlet and outlet openings (35,37) leading to and coming from an internal chamber, and a closing portion that has plates (25,27) for closing and opening the inlet and outlet openings using the force of a spring (29) and the shifting of a pin (21). An actuator controls the magnitude of shifting of the pin for regulating the amount of gas passing through the opened opening. The closing portion also includes a bellows regulated by a pneumatic actuator for allowing simultaneous opening of the inlet and outlet openings. The plates are joined by the spring and shiftable along the pin between two fixed stops. The force of the spring is used to close the inlet and outlet openings when the valve is closed. The shifting of the pin in either direction is used so that one of the plates shifts when dragged by one of the stops, opening one of the openings and keeping the other one closed. The bellows are joined to the plates, demarcating an enclosure with the pin inside. The pneumatic actuator creates a vacuum inside the enclosure to reduce the axial dimension of the bellows and allow simultaneous opening of the two openings. |
