Daikin VRV system FXMQ250AXVMB - Guidelines When Connecting the Liquid Piping

17 | Piping installation
Installer and user reference guide
52
FXMQ-A
VRV system air conditioner
4P701548-1 – 2022.07
17.2.3 Guidelines when connecting the liquid piping
INFORMATION
To connect the liquid piping use flare connection.
Take the following guidelines into account when connecting pipes:
▪ 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)
Ø9.5 33~39 12.8~13.2
R=
0.4~0.8
±2
45°
90°
±2
ØA
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).
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 b
a Cut exactly at right angles.
b Remove burrs.