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7
Refrigerant piping
CAUTION
Use fl are nuts that are included with the unit. Using
different fl are nuts may cause refrigerant gas
leakage.
Refrigerant piping
■
Use the following item for the refrigerant piping.
Material: Seamless phosphorous de-oxidized
copper pipe.
6.35, 9.52 and 12.7 wall thickness 0.8 mm or more.
15.88 wall thickness 1.0 mm or more.
REQUIREMENT
When the refrigerant pipe is long, provide support
brackets at intervals of 2.5 - 3 m to clamp the
refrigerant pipe. Otherwise, abnormal sound may
be generated.
CAUTION
IMPORTANT 4 POINTS FOR PIPING WORK
1. Reusable mechanical connectors and fl ared
joints are not allowed indoors. When mechanical
connectors are reused indoors, sealing parts shall
be renewed.
When fl ared joints are reused indoors, the fl are
part shall be re-fabricated.
2. Tight connection (between pipes and unit)
3. Evacuate the air in the connecting pipes by using
VACUUM PUMP.
4. Check the gas leakage. (Connected points)
Pipe size
Gas side
22.2 mm
Pipe size
Liquid side
12.7 mm
Liquid side refrigerant pipe
connection
Permissible piping length and height
difference
They vary according to the outdoor unit.
For details, refer to the Installation Manual attached to
the outdoor unit.
29-EN
Flaring
Cut the pipe with a pipe cutter.
Remove burrs completely.
Remaining burrs may cause gas leakage.
Insert a flare nut into the pipe, and flare the pipe.
As the flaring sizes of R32 or R410A differ from those of
refrigerant R22, the flare tools newly manufactured
for R32 or R410A are recommended.
However, the conventional
tools can be used by adjusting
projection margin of the copper
pipe.
Projection margin in fl aring: B (Unit: mm)
RIDGID
(Clutch type)
Outer dia. of
Conventional
Tool used
copper pipe
tool used
12.7
0 to 0.5
1.5 to 2.0
Flaring dia meter size: A (Unit: mm)
+0
Outer dia. of copper pipe
A
-0.02" (–0.4)
1
2
7 .
1
6
6 .
CAUTION
•
Do not scratch the inner surface of the fl ared part
when removing burrs.
•
Flare processing under the condition of scratches on
the inner surface of fl are processing part will cause
refrigerant gas leak.
•
Check that the fl ared part is not scratched,
deformed, stepped, or fl attened, and that there
are no chips adhered or other problems, after fl are
processing.
•
Do not apply refrigerating machine oil to the fl are
surface.
* In case of fl aring for R32 or R410A with the
A
conventional fl are tool, pull it out approx.
0.5 mm more than that for R22 to adjust
to the specifi ed fl are size.
The copper pipe gauge is useful for
adjusting projection margin size.
– 15 –
Tightening connection
CAUTION
Do not apply excessive torque. Otherwise, the
nut may crack depending on the conditions.
Outer dia. of copper pipe
Tightening torque
12.7 mm (dia.)
Tightening torque of fl are pipe connections
B
Pressure of R32 or R410A is higher than that of R22.
(Approx. 1.6 times) Therefore, using a torque wrench,
tighten the fl are pipe connecting sections which
connect the indoor and outdoor units of the specifi ed
tightening torque.
Incorrect connections may cause not only a gas leak,
but also a trouble of the refrigeration cycle.
Align the centres of the connecting pipes and tighten
the fl are nut as far as possible with your fi ngers. Then
tighten the nut with a spanner and torque wrench as
shown in the fi gure.
Half union
Flare nut
Externally
threaded side
Use a wrench to secure.
Use a torque wrench to tighten.
REQUIREMENT
Tightening with an excessive torque may crack the
nut depending on installation conditions.
Tighten the nut within the specifi ed tightening
torque.
Gas side refrigerant pipe
connection
Turn up the pipe heat insulator to the unit side.
Wrap the pipe with wet cloth.
Turn up pipe heat
insulator
Wet cloth
Remove the all
brazed part.
Remove the cup on the gas side piping by using a
brazing machine.
CAUTION
Do not burn the pipe heat insulator.
Be careful for the flame, due to the brazing
process on the ceiling.
Connection pipe
Locally procured
Ø22.2 mm
Braze the connection piping to the joint part.
Braze all around
Turn back the pipe heat insulator and tie up with a
banding band.
Internally
Tie up with a banding
threaded side
band.
Piping with outdoor unit
For details of installation, refer to the Installation
Manual of the outdoor unit.
Evacuation
Using a vacuum pump, perform vacuuming from the
charge port of valve of the outdoor unit.
For details, follow to the Installation Manual attached
to the outdoor unit.
Never use the refrigerant sealed in the outdoor unit
for evacuation.
REQUIREMENT
For the tools such as charge hose, etc., use those
manufactured exclusively for R32 or R410A.
Remove the cap
EN
EN
EN
EN
30-EN
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