Pneumatic Actuator-Spring Return (Fail Safe)

 

The operating principle of single acting spring return actuator Sizing example of HAITIMA spring return actuator: Spring to close when air fails (air to open): Valve torque 60N.m plus 30% safety factor=78N.m. Minimum operating pressure:6bar. The spring return HAITIMA actuator selected is HTS-125-10. The HTS-125-10 has the following output torques: 1.air torque 0°(valve close)=173N.m > 78N.m 2.air torque 90°(valve open)=118N.m>78N.m 3.spring torque 90°(valve open)=156N.m > 78N.m 4.spring torque 0°(valve close)=119N.m > 78N.m CCW-counter-clockwise Air to port A forces the pistons outwards, causing the springs to compress. The pinion turns counter-clockwise while air is being exhausted through port B. CW-clockwise Loss of air pressure through port A allows the stored energy in the springs to force the pistons inwards. The pinion turns clockwise while air is being exchausted through port A.

    

Mounting Variations	Spring Arrangement
CCW-counter-clockwise CW-clockwise