MovinCool Classic 10 Service Manual - Manual (Page 62)

Repair Section 62
(3) Cleaning brazing filler metal and pipe
• When the refrigeration system has been opened and exposed to the heat which could cause
the brazing filler metal to stick to the inside and outside of the pipe. Brazing filler metal may also
be compounded with oxygen in the air to form the oxide film. In addition, grease and oils may
stick to the pipe during handling. All these factors can reduce the effectiveness of brazing . It
is necessary to eliminate the excessive brazing filler metal using sand paper and by thorough
cleaning with solvent such as Trichlene.
(4) Use of Dry Nitrogen gas
• During brazing, the inside of the pipe undergoes an oxidative reaction due to the brazing flame.
Introduce dry nitrogen gas (0.27 gal/min (1 L/min); adjust with the flow regulator) through the
pinch-off tube of the refrigerant cycle to prevent oxidation.
< NOTE >
(5) Vertical joint
• Heat the entire brazed fitting to a proper
brazing temperature. Bring the brazing filler
metal into contact with the fitting so that the
brazing filler metal starts to flow by itself.
• Stop heating the fitting as soon as the brazing
filler metal has flown into the gap (clearance).
Since the brazing filler metal flows easily into
the portions heated to a proper temperature, it
is essential to keep the whole fitting at a proper
brazing temperature.
I000564
Burner
45°
Tube
Brazing Filler Metal
Vertical Down Joint
I001725
Burner
45°
Tube
Brazing Filler Metal
Vertical Up Joint
CAUTION
• Do not use chlorine cleaner
• Make sure not to allow dirt, water, oil, etc . to enter into the pipes.