| 摘要 |
A valve assembly includes a valve body, a valve element, a valve actuator, and a fluid-operated switch. The valve body defines a flow passage. The valve element is disposed at least partially within the flow passage and is moveable between an open position and a closed position. The valve actuator is coupled to the valve element and is responsive to pressurized fluid supplied thereto and vented therefrom to move the valve element between the open position and the closed position, respectively. The fluid-operated switch has a first fluid inlet, a second fluid inlet, a third fluid inlet, an actuator port, and an actuator vent port. The fluid-operated switch is in fluid communication with the valve actuator and is operable to selectively supply pressurized fluid to the actuator via the actuator port, and vent the pressurized fluid from the actuator via the actuator port and the actuator vent port. |
