My Linde Nitrogen purging regulator doesn't regulate pressure to well below about 25 PSI. Other then buying a low flow setup how do you all keep a very low Nitrogen purge flowing while brazing linesets.
If you dry fit all the lineset connections and give it a good Nitrogen purge and then shut off the flow will the residual Nitrogen keep the Oxygen from invading. Nitrogen is only one notch lighter then Oxygen so I don't think it's going to get too anxious to escape.