Okay, I was given this Anheuser-Busch pony keg the other day. It's got two of these valves on it. One on the top and one on the bottom side. It also has a bung on the side. I initially thought it was a U - type valve system, but I'm not so sure. And I can't figure out how to get that retainer ring off... help?
http://i68.photobucket.com/albums/i37/cossda/IMG_1787.jpg
http://i68.photobucket.com/albums/i37/cossda/IMG_1787.jpg