17
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Piping installation
Installer and user reference guide
53
FXMQ-A
VRV system air conditioner
4P701548-1 – 2022.07
3
Remove the flare nut from the stop valve and put the flare nut on the pipe.
4
Flare the pipe. Set exactly at the position as shown in the following figure.
A
Flare tool for R410A or
R32 (clutch type)
Conventional flare tool
Clutch type
(Ridgid-type)
Wing nut type
(Imperial-type)
A
0~0.5 mm
1.0~1.5 mm
1.5~2.0 mm
5
Check that the flaring is properly made.
a
b
c
a
Flare’s inner surface MUST be flawless.
b
The pipe end MUST be evenly flared in a perfect circle.
c
Make sure the flare nut is fitted.
17.2.4 Guidelines when connecting the gas piping
INFORMATION
To connect the gas piping use the attached piping (accessory).
NOTICE
▪
Join the attached piping (accessory) and the field refrigerant piping (field supply)
by brazing before fixing the attached piping to the unit.
▪
Do NOT braze the refrigerant piping directly to the indoor unit.
Mind following guidelines for brazing:
To braze the field piping to the attached piping
▪
When brazing, blow through with nitrogen to prevent creation of large quantities
of oxidized film on the inside of the piping. This film adversely affects valves and
compressors in the refrigerating system and prevents proper operation.
▪
Set the nitrogen pressure to 20 kPa (0.2 bar) (just enough so it can be felt on the
skin) with a pressure-reducing valve.
a
b
c
d
e
f
f
a
Refrigerant piping
b
Part to be brazed
c
Taping
d
Manual valve
e
Pressure-reducing valve
f
Nitrogen
▪
Do NOT use anti-oxidants when brazing pipe joints.
Residue can clog pipes and break equipment.