HI
we have a hydraulic actuator installed at our site which we want to modify to have the fail action position as fail last, for both power failure and hydraulic failure. I see there are two options for power failure case, option one is to keep the actuator full of hydraulic (two hydraulic operated pilot valves for open and close as normally open, meaning hydraulic keeps flowing to actuator during power failure) and the other option is to cut the hydraulic supply to the actuator during power failure, through the closing of pilot valves. My question is , is there an advantage of one option over an another and which one I have to go for ?
Thank you for your comments
In reply to Hakon Espvik:
In reply to john :