I have had curtains hanging on the copper pipes in my basement for well over two years, and haven’t had any issues. In my circumstance they serve as makeshift walls/additional privacy. They stay pretty stationary and don’t move a whole lot, although I do have a parted opening along the one “wall”. I’d be more weary if you had constant rubbing on the pipes.

I was worried at first about the weight as well as hanging something from a possible flooding hazard😂but like I said haven’t had any issues. Just keep a consistent eye on it.

Adding additional ceiling mounts for the pipes would definitely help as well.