If your system starts leaking mid run and you want to “tighten” your brass nuts but they were already properly torqued, use another brass nut behind it as a backer before you tighten. I had a tech back in the trap days panic when the collection pot started leaking. He started cranking the nut tighter and the system was -60 and the nut gave out. Shot the collection pot through the roof of a house, material column sticking out the roof, the 12" clamp popped off and broke his collar bone. Only 18 psi in the system but on 12" that is alot of pressure. The backer nut in these situations will hold the clamp on if one nut breaks. the trick is to have no gap between nuts and tighten both at the same time.