The brazing process is carried out in an inert atmosphere to avoid oxidation and the resultant impurities from contaminating the refrigerant system. Specially selected brazing equipment and fixtures are used to produce high quality brazing. The joints are pressure-tested to check weld strength and leakage. The coils are then tested for fine leaks with ultra-sensitive electronic leak detectors. An automated coil brazing line from Korea ensures consistent quality brazing and leak proof joints.