Valves for anhydrous ammonia service

[fri52tz]

What is a good, basic isolation valve for anhydrous ammonia service, not refrigerated storage. We currently have SS gate valves, 2" and 3" 300# class that are not sealing well at all under nitrogen pressure testing. Is a gate valves appropriate for this service?, metal to metal ball valves or soft seat ball valves?

 

[unclesyd]

The only valve we ever used in anhydrous NH3 service was Vogt. 90% of our valves were Globe. We have anhydrous NH3 in all flavors. The only thing we didn’t do was make it.

They did have a very good brochure on NH3.
The second site has some very good physical data on NH3.

http://flowserve.vogtvalves.com/products.asp

http://www.ammoniapro.com/techincal_information.htm