Caution!
The brass valve in a propane cylinder will be damaged if it comes in contact with anhydrous ammonia. This deterioration will lead to cracking of the valve body or its components and can ultimately result in a violent, unexpected expulsion of the valve from the cylinder, causing personal injury or death.
From National Propane Gas Association
more info
http://www.npga.org/i4a/pages/index.cfm?pageid=529



