17
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Piping installation
Installer and user reference guide
63
FXUA50~100AVEB
VRV system air conditioner
4P673843-1 – 2022.01
▪
Coat the flare inner surface with ether oil or ester oil when connecting a flare
nut. Tighten 3 or 4 turns by hand, before tightening firmly.
▪
ALWAYS use 2 wrenches together when loosening a flare nut.
▪
ALWAYS use a spanner and torque wrench together to tighten the flare nut when
connecting the piping. This to prevent nut cracking and leaks.
a
b
c
d
a
Torque wrench
b
Spanner
c
Piping union
d
Flare nut
Piping size (mm)
Tightening torque
(N•m)
Flare dimensions
(A) (mm)
Flare shape (mm)
Ø6.4
15~17
8.7~9.1
R=
0.4~0.8
±2
45°
90°
±2
ØA
Ø9.5
33~39
12.8~13.2
Ø12.7
50~60
16.2~16.6
Ø15.9
62~75
19.3~19.7
17.2.4 Pipe bending guidelines
Use a pipe bender for bending. All pipe bends should be as gentle as possible
(bending radius should be 30~40 mm or larger).
17.2.5 To flare the pipe end
NOTICE
▪
Incomplete flaring may cause refrigerant gas leakage.
▪
Do NOT re-use flares. Use new flares to prevent refrigerant gas leakage.
▪
Use flare nuts that are included with the unit. Using different flare nuts may
cause refrigerant gas leakage.
1
Cut the pipe end with a pipe cutter.
2
Remove burrs with the cut surface facing down so that the chips do NOT enter
the pipe.
a
b
a
Cut exactly at right angles.
b
Remove burrs.
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.
