Flange are you serious that you've seen this before?
btw mike those rheems seem small to be 5 tons. what's on the third floor?
not that it matters, but have the panel covers been switched?
& why do they need 4 or 5 tons of air on the third floor? Throw in a picture of the furnace if you can.
These are heat expansion loops so that between winter and summer due to the thermal expansion coefficient of copper the pipe doesn't buckle. I believe these are required by code....in an oil pipeline in Alaska.