Tube Brazing - Panasonic 4CW056MA01 Applications Manual

4.4 Tube Brazing

During brazing the system piping to the compressor, it is important to maintain the cleanliness inside the
piping to prevent water, solid contamination and so on entering into the system. Do not bend the discharge
or suction lines or force the piping into the compressor connections since this may increase piping stress and
potential failure. See figure below for recommended materials and procedure.
4.4.1 Brazing material:
A silver-phosphorus and other silver brazing materials are recommended for all kinds metal brazing. A copper-
phosphorus brazing material is also acceptable for copper brazing.
See Table 4-1 for recommended brazing materials.
Table 4-1: Recommended Brazing Material
Metal
Copper to Copper
Copper to Steel with copper
coated
*Copper to Steel
*Steel with copper coated to
steel
*Steel to Steel
4.4.2 Nitrogen purge
During brazing the system piping to the compressor a Nitrogen purge with high purity (99.8% min.) must be
used to prevent oxidation contamination. The nitrogen purge cannot be stopped until the piping temperature
below 200℃. See Figure 4-2 below for recommended flow method of nitrogen purge.
Figure 4-2 The flow method to prevent the oxidation contamination
Silver (%) JIS Code
4.8~5.2 BcuP-3
35 BAg-2
45 BAg-1
18
Brazing Temp.℃
720~815
700~845
620~760
oxidation contamination
JIS standard
Z 3264
Z 3261
Z 3261