Control valves

Hey all. Im back to pick your collective brains again. Im attempting to locate a new control valve system. Currently we use either the built in valves on our flow meters (which work great, but the flow meters dont) or we mount a port valve and attach a honeywell modutrol motor too it with a bracket and linkage setup. The bracket and linkage is far from ideal tho. What I would like to find is some sort or control valve / port valve that has built actuator with 4-20 control. Anyone know of any products like this? I havent had much sucess myself. Thanks

Matt

We have used badger control valves for a number of years.

http://www.badgermeter.com/rcvr.htm

You didn't say what size or what you are controlling.


http://www.emersonprocess.com/fisher/products/index.html
http://www.samson.de/main/enpro003.htm
http://www.flowserve.com/eim/Products/HeritageBrands/Valtek?flsview=product
http://www.masoneilan.com/

Check out Bosch modules. We have used them a lot with Profibus modules for remote modules.....

Were typically controlling hydrocarbons (methane, propane, etc), air, ammonia, and hydrogen (as well as mixes of h2 from cracked hyrdocarbons or dissassociated ammonia). Pipe sizes are 3/4" to 4".

Thanks!

Just curious, what are these "built in valves on our flow meters"?
What type of flow meters?

It suprises me that you're working in the process industries and several valve manufacturer's haven't found you already.

Aren't some of those gases hot, coming out of the dissociation process?

Presumably you drive the Modutrol actuator with a 4-20mA?

Anyhow, somehow or other you have to power the actuator. The choice is pneumatics (air) or electric.

Two advantages of the electric Modutrol actuator:
- mounting puts it above and away from the valve where it cooks less if the medium through the valve is hot.
- electrically powered, you don't need instrument quality air, meaning, clean (no oil) and dry (low dewpoint).

If you switch to a pneumatic actuator, there are costs of either providing and maintaining instrument air or dealing with what dirty air does to the I/P or pneumatic positioner that converts your 4-20mA signal to pneumatics.

It sounds like the non-flow-meter valves work OK. What is a port valve? Is it a butterfly style valve or a globe (plug) valve?

Are you going through all this to get rid of linkage? What's the real problem with linkage? Setup? It sticks out and gets knocked around and bent? Never quite right? Non-linear response?

Dan