Using a Protective Atmosphere During Brazing of HVAC&R Copper Tubing and Its Effect on Braze Quality and System Contamination

Brazing is a practical, fast and relatively low cost joining method.  Both aluminum and copper heat exchangers and many miscellaneous component connections are brazed.  In addition, field service repair often requires re-brazing that can take place under less-than-ideal conditions.  However, to achieve a reliable and leak-free braze joint, adequate surface preparation and proper control over heating parameters are required.  Unfortunately, if inadequate brazing techniques are used, thermal degradation at the interior surfaces of tubing can take place.  The degradation can lead to the formation of scale that may dislodge and cause contamination of bearings or valves in the HVAC&R system.