Rob G· Registered
John, I use the Milwaukee regulator and do not use any teflon tape. The CGA 320 fitting (I believe that's what it is) is not designed to be used with teflon. All you need to use is one nylon washer (my regulator came with two, so that could be confusing). As long as you use a wrench to get it properly tightened, it shouldn't leak. I would also suggest making sure the threads on your cylinder are very clean. The welding shop where I exchange mine often has very dirty cylinders. Even a small amount of dirt could possibly result in a leak.