In the event of non pressureized piping (i.e. Medical Air Intake, Medical Vacuum Exhaust, Manifold Relief Lines, etc), if all of section 5.1.10 is being met, should all of the applicable installer and verifier test be completed?

Although 5.1.12.1.2 says all pipelines qualify, my concern is this piping is not part of the [pressurized] distribution piping system. 

Our specific situation is an exhaust line needing to be offset and extended by 6 feet with 3 elbow fittings. Does the installers initial pressure test and 24 hour standing pressure test need to be completed?

On the other hand, I've seen oil dripping from bad braze joints on Vacuum exhaust. If the installer pressure test don't have to be performed, how can these bad joints be identified?

*Reference NFPA 99, 2018 edition for this topic.