(7) Cautions for Brazing Work
(A) For piping connections, complete non-oxidation brazing with a nitrogen charge. If brazing the pipes
without the nitrogen substitution, a large amount of oxidized scaling will be generated in the piping. This
oxidized scaling can cause clogging inside the expansion valve, solenoid valve, accumulator, and
compressor, which can damage the unit.
Do not use field-supplied antioxidant which can corrode pipes and degrade the refrigerant oil.
NOTE:
Make sure to use nitrogen. Nitrogen gas pressure shall be 0.02 MPa or less.
Make sure to use the pressure-reducing valve.
Do not use field-supplied antioxidant.
(B) Use a type of flux with a low chlorine concentration.
(C)
Washing the weld joints to remove all flux completely after completing brazing work.
NOTE:
To avoid oxidation and scaling, perform brazing at the appropriate temperature.
(D) To prevent gas leakage at the brazing connection, refer to the table for the insertion depth and the
gap for joint pipe.
Unit: mm
Diameter
ΦD
Min. Insertion
De
th
B
Gap (A - D)
5≤ D <8
6
0.05 - 0.35
8≤ D <12
7
12≤ D <16
8
0.05 - 0.45
16≤ D <25
10
(8) Cautions for Flaring Wo
rk
(A) Perform the flaring work as shown below:
Unit: mm
Diameter
(Φd)
A
+0
-0.4
R410A
6.35 9.1
9.52 13.2
12.7 16.6
15.88 19.7
19.05 （*）
(*): It is impossible to perform flaring work with hard temper pipe. Use an accessory pipe with a flare.
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