Been creeping this forum for a bit prior to my project. I have a question about the plumbing for my project. The Project. I'm attempting a tile shower. I ripped out my old shower and replaced the runs to line up with the new valve. The brass nipples that came with the valve won't thread in the copper adapter that I purchased. They also won't thread in backwards to the Escutcheon so I'm pretty sure it's not the threads in the copper adapter. Here's a pic of the connection I'm attempting.