Could you provide some information on the service and size of the valve? Does it have to be Hitachi or would another manufacturer work?
What material in piping? What pressure? What kind of equipment?
My internet search came up dry. Do you have a Hitachi contact you could ask?
Sorry that I have more questions than answers!
__________________
Eventually, one needs to realize that it is far less important to be the smartest person in the room than it is to sit next to that person and make friends.