F1 series spring return pneumatic actuator

I   Operating Principle

CCW
Air to Port A forces the pistons outwards,causing the springs to compress,Thepinion turns counterclockwise while air is being exhausted from Port B.
CW
Loss of air pressure,the stored energy in the springs forces the pistonsinwards,the pinion turns clockwise while air is bing exhausted from PortA.

II Model andspecification

III   Sizing:SpringReturn Actuators
1. The suggested safety factor for spring return actuator under normal workingconditions is 30-50%
The torque needed by valve=80N.m
The torque consider safety factor(1+30%)=104N.m
Air Supply=5Bar
According to the table of spring return actuators’output,we find output torqueof SR105   K7 is:
Air stroke 0°=308N.m
Air stroke 90°=247N.m
Spring stroke 90°=181N.m
Spring stroke 0°=120N.m
All the output torque is larger than we needed.
During the restoration,the spring return actuators’output torque will notbe affected by the inputing air from the portB.On thecontrary,it will help therestoration of springs.

2.EconomicalSizijng:Spring Return Actuators
During selecting the spring return actuators,we can choose the more reasonableand more economical actuators, if we know the different torque needed by thevalve working at opening, operating and closing.
Example:
The max torque needed by the butterfly valve=104N.m
The torque after opened (openating)104*30%=32N.m
Air Supply=5Bar
We can select the SR125   K11
Output torque is:
Air stroke 0°=135N.m>104 N.m
Air stroke 90°=75 N.m>32 N.m
Spring stroke 90°=172 N.m>32 N.m
Spring stoke 0°=115 N.m>104 N.m
The above data shows that the butterflyvalve can meet the normal start.

IV   OutputTorque Of Spring Return Actuators

V   MountingConnection And Dimension

VI Air consumption & Weight table

1.Air consumption table

2.Weight table

　　　FI series spring return pneumatic actuators（Download）