I think this is what's going on. The 1" lock nut is welded to the big TC end cap. The element screws in from the other side of the end cap. The other side of the lock nut has a smaller TC ferrule welded to it. That ferrule mates up to a ferrule that's welded to the keg. It's a little hard to figure out because the smaller TC clamp is in the way, preventing you from seeing that the smaller ferrule is no attached to it's other half... I think.