AW single-acting actuator has larger output torque than AT actuator. The output torque can be changed with the change of angle by using fork drive mechanism. At the opening or closing position of the valve, the maximum value of the torque is in accordance with the law of the valve. Secondly, the height of the fork and fork arm coincides, which greatly saves space and meets all kinds of large rotary valves. Door requirements. With the advantages of safety and explosion-proof, it has been widely used in power plants, chemical industry, oil refining and other production processes with high safety requirements.