EDIT: Sorry, it's gone! Ok, I have a 4" round cabinet Port I ordered by accident, I clicked the wrong item. Port length is about 4 ", and it is black plastic with a radiused front edge. Pic down below. I don't need it, and it needs a good home, so I will send it FREE to any TB supporting member who would like it in his or her DIY junk closet. PM me the mailing addy, and it is yours as an extra reward for your support.
Yes, it would probably cover a 4" cast iron nipple fairly effectively. You may need duct tape, though.
It keeps falling out of my electrical cabinet when I open it ... I'm getting tired of catching it. Maybe I WILL send it to NJL. GOD KNOWS WHAT HE WOULD USE IT FOR!
Thus, since the port is a pressure device, and not particular about location, it can be installed in the top of a cabinet, and double as a brew holder.
Hey, if you don't need it for your cab, you could bolt it to your riding tractor as a beer holder. I would do that, but then I would have to buy a riding tractor, and a shed to store it, so that is a little over the top. C'mon, step up, free schwag!!!! Sure is hard to give stuff away around here ....