EDM SYSHP MINI SPLIT 06 16

Table Of Contents
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Figure 3-3.6: Flowing nitrogen from shorter side during brazing
Box connued on next page …
3.7 Brazing
Care must be taken to prevent oxide forming on the inside of copper piping during brazing. The presence of oxide in a refrigerant
system adversely aects the operaon of valves and compressors, potenally leading to low eciency or even compressor failure.
To prevent oxidaon, during brazing nitrogen should be owed through the refrigerant piping.
Notes for installers
Warning
Never ow oxygen through piping as doing so aids oxidaon and could easily lead to explosion and as such is extremely
dangerous.
Take appropriate safety precauons such as having a re exnguisher to hand whilst brazing.
Flowing nitrogen during brazing
Use a pressure reducing valve to ow nitrogen through copper piping at 0.02-0.03MPa during brazing.
Start the ow before brazing starts and ensure that the nitrogen connuously passes through the secon being brazed unl
the brazing is complete and the copper has cooled down completely.
When joining a shorter secon of piping to a longer secon, ow nitrogen from the shorter side to allow beer displacement
of air with nitrogen.
If the distance from the point where nitrogen enters the piping to the joint to be brazed is long, ensure that the nitrogen is
owed for sucient me to discharge all the air from the secon to be brazed before commencing brazing.
Figure 3-3.5: Flowing nitrogen through piping during brazing
Braizing
Braizing
Nitrogen
Secon being brazed
Shorter secon of piping
Nitrogen
Shorter secon of piping
Elbow joint
Legend
1 Copper piping
2 Secon being brazed
3 Nitrogen connecon
4 Hand valve
5 Pressure-reducing valve
6 Nitrogen