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Refrigerant piping connection
CAUTION
Take note of these 4 important points below for piping work
1. Keep dust and moisture away from inside the connecting pipes.
2. Tightly connect the connection between pipes and the unit.
3. Evacuate the air in the connecting pipes using a VACUUM PUMP.
4. Check for gas leaks at connection points.
Flaring
1. Cut the pipe with a pipe cutter.
Correct
Obliquity
90°
2. Remove the burr inside of the pipe.
When removing the burr, be careful so that chips do not fall into the pipe.
3. Remove the flare nuts attached to the outdoor / indoor unit, then insert them into each of the pipes.
4. Flare the pipes.
See the following table for the projection margin (A) and flaring size (B).
*The conventional tools can be used by adjusting the projection margin of the copper pipe.
A
Pipe
A
Outside
Rigid (clutch type)
Conventional (wing
Thickness
diameter
R32 or R410A tool
mm
mm
mm
6.35
0.8
0 to 0.5
9.52
0.8
0 to 0.5
12.70
0.8
0 to 0.5
15.88
1.0
0 to 0.5
REQUIREMENT
• For a brazing work of the refrigerant pipes, be sure to use nitrogen gas in order to prevent oxidation of the inside of the
pipes; otherwise clogging of the refrigerating cycle due to oxidized scale may occur.
• Use clean and new pipes for the refrigerant pipes and perform piping work so that water or dust does not contaminate the
refrigerant.
* Remove all flux after brazing.
• Be sure to use a double spanner to loosen or tighten the flare nut. If a single spanner is used, the required level of tightening
cannot be obtained. Tighten the flare nut with the specified torque.
• Do not apply refrigerant oil to the surface of the flare.
53-EN
Incorrect
Roughness
Warp
B
B
Flare Nut
Width across
Tighten torque
nut type) tool
flat
mm
mm
mm
N•m
1.0 to 1.5
9.9
17
14 to 18
1.0 to 1.5
13.2
22
33 to 42
1.0 to 1.5
16.6
26
50 to 62
1.0 to 1.5
19.7
29
68 to 82
– 27 –
Coupling size of brazed pipe
External size
K
Standard outer dia.
of connected
copper pipe
6.35
9.52
12.70
15.88
kgf•m
1.4 to 1.8
3.3 to 4.2
5.0 to 6.2
6.8 to 8.2
Connected section
Internal size
G
Connected section
External size
Internal size
Min. depth of
Standard outer dia.
insertion
(Allowable difference)
C
F
K
6.35 (±0.03)
6.45 (
+0.04
)
7
-0.02
9.52 (±0.03)
9.62 (
+0.04
)
8
-0.02
+0.04
12.70 (±0.03)
12.81 (
)
9
-0.02
15.88 (±0.03)
16.00 (
+0.04
)
9
-0.02
(Unit: mm)
Min. thickness
of coupling
Oval value
G
6
0.06 or less
0.50
7
0.08 or less
0.60
8
0.10 or less
0.70
8
0.13 or less
0.80
54-EN
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