Denso MovinCool CLIMATE PRO K63 Service Manual page 85

Brazing
4. Use of dry nitrogen gas
The brazing flame oxidizes the inner surface of the pipe. To prevent this, introduce dry nitrogen
gas from the pinch-off tube of the refrigeration cycle at a rate of 0.27 gal/min (1 L/min); adjust
with the flow regulator.
Note:
Take care not to allow dirt, water, oil to enter the pipe.
5. Vertical Joint
Heat the pipes so that heat is evenly
transmitted throughout the fittings.
a) Vertical Down Joint
When the fitting surface reaches the
brazing temperature, add brazing metal
and continue to heat, moving the burner
downward as shown. The melted brazing
metal flows toward higher temperature.
b) Vertical Up Joint
Move the burner upward as shown. The
brazing metal will flow upward through
capillary action and through its nature of
flowing toward higher temperature.
45°
Pipe
Pipe
45°
85
Vertical Down Joint
Brazing Filler Metal
Burner
Vertical Up Joint
Burner
Brazing Filler Metal