Pipe Installation; Selecting The Pipe Material; Pipe Requirement; Flare Connection (Pipe Connection) - Fujitsu Airstage AUXD18GALH Installationsanleitung

4. PIPE INSTALLATION

Be more careful that foreign matter (oil, water, etc.) does not enter the piping than
with refrigerant R410A models. Also, when storing the piping, securely seal the
openings by pinching, taping, etc.
While welding the pipes, be sure to blow dry nitrogen gas through them.

4.1. Selecting the pipe material

Do not use existing pipes from another refrigeration system or refrigerant.
Use pipes that have clean external and internal sides without any contamination
which may cause trouble during use, such as sulfur, oxide, dust, cutting waste, oil, or
water.
It is necessary to use seamless copper pipes.
Material : Phosphor deoxidized seamless copper pipes
It is desirable that the amount of residual oil is less than 40 mg/10 m.
Do not use copper pipes that have a collapsed, deformed, or discolored portion
(especially on the interior surface). Otherwise, the expansion valve or capillary tube
may become blocked with contaminants.
Improper pipe selection will degrade performance. As an air conditioner using
R410A incurs pressure higher than when using conventional (R22) refrigerant, it is
necessary to choose adequate materials.
• Thicknesses of copper pipes used with R410A are as shown in the table.
• Never use copper pipes thinner than those indicated in the table even if they are
available on the market.
Thicknesses of Annealed Copper Pipes (R410A)
Pipe outside diameter [mm (in.)]
6.35 (1/4)
9.52 (3/8)
12.70 (1/2)
15.88 (5/8)
19.05 (3/4)

4.2. Pipe requirement

Refer to the installation manual for the outdoor unit for description of allowable pipe
length and height difference.
Use pipe with water-resistant heat insulation.
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 location of the refrigerant piping
is expected to exceed 70 %, install heat insulation around the refrigerant piping.
If the expected humidity level is 70 to 80 %, use heat insulation that is 15 mm or
thicker and if the expected humidity exceeds 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 0.045 W/(m·K) or less (at 20 °C).
En-5
9371022260-01_IM.indb Sec1:5 9371022260-01_IM.indb Sec1:5
CAUTION
CAUTION
Thickness [mm]
0.80
0.80
0.80
1.00
1.20
CAUTION
CAUTION

4.3. Flare connection (pipe connection)

WARNING
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 hazardous gas if the refrigerant comes into contact with a fl ame.
4.3.1. Flaring
Use special 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 (or
RB unit) respectively) onto the pipe and perform the fl are processing with a fl are tool.
Use the special R410A fl are tool. Leakage 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, clutch
[mm (in.)]
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 (R22) 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 measure the dimension A.
It is recommended that a R410A fl aring tool is used.
Width across Pipe outside diameter
fl ats [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 in 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 3 times.
CAUTION
To prevent breaking of the pipe, avoid sharp bends.
If the pipe is bent repeatedly at the same place, it will break.
Check if [L] is fl ared uniformly and
is not cracked or scratched.
L
0
Dimension B
[mm]
- 0.4
9.1
13.2
16.6
19.7
24.0
Width across flats of Flare nut
[mm]
17
22
26
29
36
7/12/2012 4:02:48 PM 7/12/2012 4:02:48 PM