Dear habib
Thanks for reply,
The system configuration is as you mentioned above. And the PCV size is 2" diameter (On a 3" line).
I've checked stress and loads due to thermal expansion and etc; no problem.
The only thing is regarding the stop for the PCV which as you mentioned is a normal routine; but in my case, the connection to the tank can act as a semiANC for the system.
By the way, do you know how to calculate the loads caused by this kind of valve while opening or closing? I guess it opens/closes gradually so there shouldn't be too much momentum. I'm not sure yet, so I need to calculate the load to its maximum possible amount it can reach: ( PCV bore area X Maximum pressure difference).

Best