Originally Posted by Shelby
Unscrewing the nut only removes the top half of the thingamajig.
Interesting! Hmm... So can I use this for serving homebrew you think? The opposite side has what appears to be a standard sanke a type fitting.
Unscrewing it should remove the whole coupler, which I'm guessing is what you're referring to as the "top half". It should look like this-
The part the coupler connects to is the valve. Generally the valve is left in place. It can be removed with an allen wrench, screwdriver, and pipe wrench, but this method often damages the valve. To remove it without damaging it typically requires a special tool that's hard to find. If it has the c-clip instead of the 3 set screws, you might be able to remove it without the special tool pretty easily, but that type is very rare.
It really appears that the valve is mounted in some sort of adapter so that it can be used in a type D sankey keg, which is what it looks like underneath. If so, you should be able to remove the valve and adapter just like you would remove a sankey spear. First pull the spiral retaining ring out, and then twist slightly so that the ears line up with the notches, and pull up. Then you'd need to install a sankey spear assembly to be able to use it, but with the way it's angled, I'm not sure it would work right. As long as the valve gaskets are good, you should be able to serve homebrew out of it. What kind of spear/diptube does the sankey side have?