Regarding NFPA 1 - Uniform Fire Code, Annex G Ozone Gas. Part G.5.2 allows for "Exception: Welded stainless steel piping and tubing." Does this mean the "tubing" must be welded? Or does this mean in lieu of welded pipe, stainless steel tubing may be used including common threaded ferrule fittings? We have had one project where the fire inspector approved the use of tubing with threaded ferrule fittings, but want to check with NFPA, to make sure that “welding” of pipe is not an absolute requirement.