AMG pneumatic actuators type SAD /SAF are characterized by the essential design elements rack and pinion. In this case, the rotary movement is produced by the straight movement of two pistons acting against each other. The racks of pistons are engaged with the pinion, which transmits the rotary motion to the armature. The piston movement is effected by compressed air on the piston surfaces.
The transverse forces occurring during the sliding movement of the pistons are absorbed by guide rods. This ensures a perfect axial guidance of the pistons, so that the piston seals function well and permanently.
From the principle of rack / pinion results an uniform torque course during the switching process due to the constant effective distances between the rack and pinion.
For AMG pneumatic actuators type SAD, the movement is generated with compressed air. When the outer chambers are ventilated, the switching shaft rotates clockwise (valve closes). When the internal chamber is ventilated, the switching shaft rotates counterclockwise (valve opens).
AMG pneumatic actuators type SAD are moved with compressed air and spring force. For single-acting actuators, only the inner chamber is pressurized with compressed air. The force generated thereby not only moves the valve in one direction, but tensions at the same time the safety springs for the return. The spring force is able to move the valve into the safety position "CLOSE" or "OPEN" in the event of a failure.
A general advantage of all pneumatic drives is that they can be used without problems in explosive or humid environments. In the case of leaks, there is no danger to the operating personnel.