I'm encountering a problem in my Project for the procurement of Pneumatic spring return ESD valves. In the Sizing calculations, for some valves the Actuator MAST is exceeding the Valve MAST, which I believe is not desirable.
I cannot change my DP on line & cannot reduce my safety factor (2). What is the solution now?
Can i proceed with Actuator MAST higher than Valve MAST?
Thanks in Advance!
Having now understood MAST (Maximum allowable stem shear torque), it would seem a bad idea to have the Actuator MAST exceeding the Valve MAST as you could end up with a damaged valve.
Can you explain what calculations you are making?
If these are spring return, are they fail safe closed or fail safe open?
Not really my field, but I read this paper once and it covers issues with ESV MAST calcs and might provide a direction for you: