| 摘要 |
<p>The present invention relates to an actuator including an emergency return means for a valve. More specifically, the actuator operates a valve which is opened or closed to control the flow of a fluid in a refineries, power plants, reservoirs, pumping stations, water gates, and dams. The emergency return means of the actuator returns the valve to a state prior to an operation when the power is cut off during the operation of opening or closing the valve to prevent potential safety accident which can occur when the valve stops.</p> |
