7 | Piping installation
Installer reference guide
37
2MXM-A9, 3MXM-A9, 4MXM-A9, 5MXM-A9
R32 Split series
4P600463-7G – 2022.09
▪ 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 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
Ø9.5 33~39 12.8~13.2
Ø12.7 50~60 16.2~16.6
Ø15.9 62~75 19.3~19.7
7.2.4 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).
7.2.5 To flare the pipe end
CAUTION
▪ 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 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.