propane in air fittings (sorta robot related)

[BANE]

Hello all,
Im working on a home brewed foundry for making aluminum robot parts.  Im currently working on the burner and i was wondering if anyone here is knowledgeable of low pressure propane in regular air quick release compliers.  I know propane contains butane which will eat up the rubber or plastic long term, but i probably need this running a couple hours every so often.  Currently i have to unscrew everything and its a pain the butt, the quick release would be awesome and i have a ton laying around.

any thoughts?

thnx in advance. 

[Tedtronic]

You might want to look into something CSA/UL listed for this "safety critical" application.  Expect to pay top-dollar for the convenience, though.

Snap-tite makes a quick disconnect coupler designed for gas service:
http://www.snap-tite.com/snaptite_qd/products/general_purpose_poppet_coupling/gf_series/index.html

McMaster offers a system as well as a quick coupler for welding equipment
http://www.mcmaster.com/#quick-disconnect-hose-couplings/=cbp2ms
http://www.mcmaster.com/#catalog/117/3358/=cbp0kg

Recommended seals for propane service are Teflon, Viton, or Buna-N/Nitrile Rubber.  If you are burning a propane/butane mix, you are correct that the butane will destroy natural and some synthetic rubbers.  You should be OK with Teflon or Viton.    It would be worth your while to track down the manufacturer of your couplings on hand to see if they are compatible with gas service.  Check to ensure yours aren't for "air service only."  I wouldn't, in good conscience, recommend an air-type coupling for gas service.  A leak could really ruin your day.

Please be safe.

Sources:
Dixon Valve & Coupling catalog: http://www.dixonvalve.com/dpl/public/DPL411_Optimized.pdf (warning: 40 MB download)
Cole-Parmer Chemical Compatibility Database http://www.coleparmer.com/techinfo/chemcomp.asp