I scored a couple of the Miller/Coors Home Draft mini-kegs, and wanted to use them for portable party kegs. My father-in-law and I found a way to modify them so that they can be force carbed from a large CO2 tank. This way, you can take carbonated & conditioned beer on the go, with virtually no yeast sediment.
I bought a tire valve, removed the spent CO2 cartridge from the mini-keg tap, and inserted the tire valve. Then I put the CO2 cartridge back in and marked how far it stuck out. We cut about 1/2" off the back of the EMPTY CO2 cartridge. Then I put a rubber O-ring (like you find inside garden hoses) between the tire valve and the backless CO2. Putting the whole thing back together, it was a nice tight fit. The hacked CO2 cartridge's only function is to pass the gas into the keg. It held up to 50 lb of pressure with no back-leaks.
I think those mini-kegs have a check valve so the CO2 only goes one way. I was surprised at how far I had to crank the pressure on my CO2 tank to get the keg to take gas. I didn't have any trouble with gas coming out the safety valve on the side of the tap.
I tested this with water, but haven't tried it with beer yet. I'd like to make a small batch of NA beer and get the old man set up with a party keg.
Here are the pics of my modification:
All Together Now:
Ask your less-discerning beer-swilling buddies to hold onto these for you, and you're in business. Post back if you give this a shot, and I will too.