Pipe Requirement; Flare Connection (Pipe Connection) - Fujitsu RCF24LBL Installation Manual

4.2. Pipe requirement

CAUTION
• Refer to the Installation Manual of the outdoor unit for
description of the length and the diameter of connecting
pipe or for difference of its elevation.
• Use pipe with water-resistant heat insulation.
CAUTION
• Install heat insulation around both the gas and liquid
pipes. Failure to do so may cause water leaks.
Use heat insulation with heat resistance above 120 °C.
(Reverse cycle model only)
In addition, if the humidity level at the installation loca-
tion of the refrigerant piping is expected to exceed 70%,
install heat insulation around the refrigerant piping. If the
expected humidity level is 70-80%, use heat insulation
that is 15 mm or thicker and if the expected humidity ex-
ceeds 80%, use heat insulation that is 20 mm or thicker.
If heat insulation is used that is not as thick as specifi ed,
condensation may form on the surface of the insulation.
In addition, use heat insulation with heat conductivity of
0.045W/(m·K) or less (at 20 °C).

4.3. Flare connection (pipe connection)

4.3.1. Flaring
• Use special pipe cutter and fl are tool exclusive for R410A.
(1) Cut the connection pipe to the necessary length with a
pipe cutter.
(2) Hold the pipe downward so that cuttings will not enter the
pipe and remove any burrs.
(3) Insert the fl are nut (always use the fl are nut attached to
the indoor and outdoor units respectively) onto the pipe
and perform the fl are processing with a fl are tool. Leak-
age of refrigerant may result if other fl are nuts are used.
(4) Protect the pipes by pinching them or with tape to prevent
dust, dirt, or water from entering the pipes.
B
Die
A
Pipe
Dimension A [mm]
Pipe outside
diameter
Flare tool for R410A,
[mm (in.)]
clutch type
6.35 (1/4)
9.52 (3/8)
12.70 (1/2) 0 to 0.5
15.88 (5/8)
19.05 (3/4)
When using conventional fl are tools to fl are R410A pipes,
the dimension A should be approximately 0.5 mm more than
indicated in the table (for fl aring with R410A fl are tools) to
achieve the specifi ed fl aring. Use a thickness gauge to meas-
ure the dimension A.
En-6
Check if [L] is flared uniformly
and is not cracked or scratched.
L
Dimension B
0
- 0.4
[mm]
9.1
13.2
16.6
19.7
24.0
Pipe outside
Width across
diameter [mm (in.)]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)
4.3.2 Bending pipes
• If pipes are shaped by hand, be careful not to collapse them.
• Do not bend the pipes at an angle more than 90°.
• When pipes are repeatedly bend or stretched, the material
will harden, making it diffi cult to bend or stretch them any
more.
• Do not bend or stretch the pipes more than three times.
CAUTION
• To prevent breaking of the pipe, avoid sharp bends.
• If the pipe is bent repeatedly at the same place, it will
break.
4.3.3. Pipe connection
CAUTION
• Be sure to apply the pipe against the port on the indoor
unit and the outdoor unit correctly. If the centering is im-
proper, the fl are nut cannot be tightened smoothly. If the
fl are nut is forced to turn, the threads will be damaged.
• Do not remove the fl are nut from the indoor unit pipe until
immediately before connecting the connection pipe.
• Do not use mineral oil on fl ared part. Prevent mineral
oil from getting into the system as this would reduce the
lifetime of the units.
(1) Detach the caps and plugs from the pipes.
(2) Center the pipe against the port on the indoor unit, and
then turn the fl are nut by hand.
Connection pipe
(Liquid)
Indoor unit
(3) When the fl are nut is tightened properly by your hand,
hold the body side coupling with a separate spanner, then
tighten with a torque wrench. (See the table below for the
fl are nut tightening torques.
CAUTION
• Hold the torque wrench at its grip, keeping it in the right
angle with the pipe, in order to tighten the fl are nut cor-
rectly.
• Tighten the fl are nuts with a torque wrench using the
specifi ed tightening method. Otherwise, the fl are nuts
could break after a prolonged period, causing refrigerant
to leak and generate a hazardous gas if the refrigerant
comes into contact with a fl ame.
Width across fl ats
of Flare nut [mm]
17
22
26
29
36
Connection pipe
(Gas)