Creating the Lightest Pneumatic System

[Mike Schreiber]

Originally Posted by FrankJ

Hi Ed:
Aside from being a supporter of First AutomationDirect is a next day delivery for you & they have good stock.
The AutomationDirect valves are legal this year (Cv.78) The nominal pressure rating is 20-115 PSI. The way I read the rules means a separate relief valve unless you have something that says otherwise.

Al,

My question isn't whether these valves are legal, it is whether I need to add the extra relief valve because the maximum working pressure is below 125 psi (R77D). The same question goes to these AutomationDirect valves. It doesn't make sense to me to add it because they will never operate above 60psi, but according to my interpretation of the rules I need it. I understand the difference between failure pressure and operating pressure, but which does "working" refer to? Are the SMC valves only okay because IFI has said they'll operate up to that pressure, and what about the varieties of SMC valves VexPro doesn't sell?