| 摘要 |
<p>A valve operator incorporates an explosive actuator which includes an elongated twisted steel tube, for emergency use in, for example, closing a valve quickly. When the emergency arises, the explosive charge in the twist actuator is fired and the gases generated by the explosion cause the twisted steel tube to untwist. One end of the twist actuator is fixed. The other end, which is free to rotate, is connected to the valve stem. Rotation of the free end of the twist actuator moves the valve quickly to the desired emergency position, which may be either the closed or open position. Two forms are disclosed. In one, the twisted-tube actuator is a series component of the normal gear drive. In the other, the actuator is coupled or decoupled by a clutch mechanism.</p> |
