| 摘要 |
The dual actuator valve of the present invention deploys both the primary and secondary actuator elements in a single, common control chamber. Therefore, the present invention provides a dual actuator valve having dimensions that are the same as, or similar to, the dimensions of a single actuator control valve. It will be appreciated that the actuator elements may be of diaphragm type or piston type actuator elements. The primary actuator element is mechanically linked to the valve plug and regulates the flow though the valve, while the secondary actuator element remains in a fully open position. Should the primary actuator element fail to operate the valve due, for example, to diaphragm rupture, failure of the primary control system, or any other reason, the secondary control system activates the secondary actuator element, which then effects movement of the primary actuator element thereby resuming flow regulation or closure of the valve as necessary. |
