Nov 10, 2016
In this episode of the HVAC School Podcast, Bryan talks with Tim Bagnall about flowing nitrogen.
Many techs don't flow nitrogen. Some may say that it is overkill, but it has been shown that flowing nitrogen displaces oxygen while brazing and prevents harmful scale from forming on the copper. Scale is very 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 many 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 so that you do not overheat the metal.
Join us today as we discuss the following:
And much more...
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