Provided there is no thermal component to the process fluid passing through the bladder, 1.1 x process line pressure is generally accepted.
Regards
Ivan
I've seen #s varying from 60% to 90% of process line pressure. The Jesco-America pulsation dampener (liquid flows thru the dampener)recommends 60%. The Milton Roy dampener (T off the discharge line) recommends 90%.
Check their web sites for specific details around their pulsation dampeners.