In the case of single-acting actuators, the piston force produced by compressed air not only for the movement of the valve, but also for tensioning the springs for the return. On the other hand, in the case of the actuator type SADF-M 180°, the springs are preloaded separately by the pressure force in the end positions (0° and 180°, respectively) generated by compressed air. As a result, the available air torque MA is constant over the entire pivoting range. AMG SADF-M 180° actuators are designed for rotary movements of 0° and 180° and have a reproducible spring-centered 90° center position.
