Need severe service motorized proportional valve

This is a little OT but I haven't had much luck with Google. I'm looking for a proportional motorized valve, something that I can control with an analog or PWM signal (to set the % of opening). The caveat is that it needs to handle 500 deg F and 1000 psi (media is liquid polypropylene). I've found valves with this rating, and motorized proportional valves, but never in the same unit. The connection needs to be 1" FNPT (or close to it).

I'm considering building my own by retrofitting a severe service needle valve that we already have with a small motor and encoder. But there may be some issues, like how to insulate the electronics from the heat of the valve.

An off-the-shelf solution would be preferred.

Have you thought of mounting your positioner in a cooler enviroment with a displacemnt sensor on the valve for feed back. Seimens has a positioner (SIPART PS2) which could be used for such a mount.
Along with your actuator you should be able to complete your installation.

I think I would give some thought to a pneumatic actuator which was very common in this type of work. A plastic link (fiberglass ie polyester ??) and heat shields would protect the actuator. Same goes for the motor used for actuation. If a gearbox is used then the motor to gearbox coupling would shield the motor from heat also.

Do you have to heat trace these lines to keep plastic from solidifying on cooldown??

Fisher Porter used to make a lot of valves for this. Temperature 500 F and pressure 1000 are fairly close to steam applications - these may work. Boiler bunker fuel valves may come close also.

Curious as to why pressure seems so high??

Dan Bentler

Contact your local Fisher Valves rep. and let them spec it for you.

http://www2.emersonprocess.com/en-us/brands/fisher/Pages/FisherValvesInstruments.aspx