Panasonic CU-E18CKR Service Manual page 69

10.4.6. Brazing
As brazing requires sophisticated techniques and experiences, it must be performed by a
qualified person. / In order to prevent the oxide film from occurring in the pipe interior during
brazing, it is effective to proceed with brazing while letting drynitrogen gas (N2) flow.
<Brazing Method for Preventing Oxidation>
1. Attach a reducing valve to the nitrogen gas cylinder.
2. Attach a reducing valve to the nitrogen gas cylinder.
3. Apply a seal onto the clearance between the piping and inserted
pipe for the nitrogen gas in order to prevent the nitrogen gas from
flowing backward.
4. When the nitrogen gas is flowing, be sure to keep the piping end
open.
5. Adjust the flow rate of nitrogen gas so that it is lower than 0.05 m
h, or 0.02 MPa (0.2 kgf/cm
6. After taking the steps above, keep the nitrogen gas flowing until
the piping cools down to a certain extent (i.e. temperature at
which pipes are touchable with finger).
7. Completely remove the flux after brazing.
) by means of the reducing valve.
2
/
3