Flow Nitrogen Great Again
In this episode of HVAC School, Bryan talks with Tim Bagnall about flowing nitrogen.
Many techs don't flow nitrogen. Some may say it's overkill, but flowing nitrogen displaces oxygen while brazing and prevents harmful scale from forming on the copper. Scale is problematic, and it will likely ruin your copper lines if you keep those lines open to air. (The jury is still out as to whether climate/geography affect scale formation, though.)
There are different intensities for flowing nitrogen, particularly high-pressure purging and low-pressure flowing (2-5 SCFM). You may also have heard that you should flow nitrogen at 1.5-3 PSI, though SCFM is the preferred unit. Some best practices for flowing nitrogen while brazing include using wet towels or heat-resistant putty on the service ports, removing the Schrader cores, removing the TXV sensing bulb before brazing, and watching your torch control as not to overheat the metal.
Join us as we discuss:
- The proper tools and flow settings for brazing
- How the pressures should be set to SCFM and not PSI
- The possibility that geography may contribute to scale
- How to flow nitrogen in a practical way
And much more…