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3. FLARING WORK AND PIPE CONNECTION
3-1. PRECAUTIONS FOR DEVICES THAT USE R32 REFRIGERANT
• Use ester oil, ether oil, alkylbenzene oil (small amount) as the refrigeration oil applied to the flared sections.
• Use C1220 copper phosphorus, for copper and copper alloy seamless pipes, to connect the refrigerant pipes. Use refrigerant pipes with the thicknesses
specified in the table to the below. Make sure the insides of the pipes are clean and do not contain any harmful contaminants such as sulfuric compounds,
oxidants, debris, or dust.
Always apply no-oxidation brazing when brazing the pipes, otherwise, the compressor will be damaged.
WARNING:
When installing or relocating, or servicing the air conditioner, use only the specified refrigerant (R32) to charge the refrigerant lines. Do not mix it
with any other refrigerant and do not allow air to remain in the lines.
If air is mixed with the refrigerant, then it can be the cause of abnormal high pressure in the refrigerant line, and may result in an explosion and
other hazards.
The use of any refrigerant other than that specified for the system will cause mechanical failure or system malfunction or unit breakdown. In the
worst case, this could lead to a serious impediment to securing product safety.
Pipe size (mm) ø6.35 ø9.52 ø12.7 ø15.88 ø19.05 ø22.2 ø25.4 ø28.58
Thickness (mm)
0.8
0.8
0.8
1.0
1.0
1.0
1.0
1.0
• Do not use pipes thinner than those specified above.
• Use 1/2 H or H pipes if the diameter is 19.05 mm or larger.
• Be sure to have appropriate ventilation in order to prevent ignition. Furthermore, be sure to carry out fire prevention measures that there are no dangerous
or flammable objects in the surrounding area.
Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
3-2. FLARING WORK
Pipe diameter
(mm)
Nut
(mm)
A (mm)
Tightening torque
Clutch
type tool
for R32,
R410A
Clutch
type tool
for R22
Wing nut
type tool
for R22
N•m
kgf•cm
ø6.35 (1/4”)
17
0 to 0.5 1.0 to 1.5
1.5 to 2.0
13.7 to 17.7 140 to 180
ø9.52 (3/8”)
22
34.3 to 41.2 350 to 420
ø12.7 (1/2”)
26
2.0 to 2.5
49.0 to 56.4 500 to 575
ø15.88 (5/8”)
29
73.5 to 78.4 750 to 800
Tilted Uneven Burred
Good
No good
Burr
Copper pipe
Spare reamer
Pipe cutter
Smooth all
around
Even length
all around
Inside is shin
-
ing without any
scratches.
Flare nut
Die
Copper pipe
Clutch type
Flaring tool
Wing nut type
Copper
pipe
1) Cut the copper pipe correctly with pipe cutter. (Fig. 1, 2)
2) Completely remove all burrs from the cut cross section of pipe. (Fig. 3)
• Aim the copper pipe downward while removing burrs to prevent burrs from
dropping in the pipe.
3) Remove flare nuts attached to indoor and outdoor units, then put them on pipe
having completed burr removal. (Not possible to put them on after flaring work.)
4) Flaring work (Fig. 4, 5). Firmly hold copper pipe in the dimension shown in the
table. Select A mm from the table according to the tool selected.
5) Check
• Compare the flared work with Fig. 6.
• If flare is noted to be defective, cut off the flared section and do flaring work
again.
When installing the unit, securely
connect the refrigerant pipes before
starting the compressor.
When there are the ports which are
not used, make sure their nuts are
tightened securely.
WARNING
CAUTION
Indoor unit capacity
25 ~ 50
Indoor unit: M series
Liquid pipe size
ø
6.35
Gas pipe size
ø
9.52
• Use tightening torque table above as a guideline for indoor unit side union joint
section, and tighten using two wrenches. Excessive tightening damages the
flare section.
1) Apply a thin coat of refrigeration oil (G) to the flared ends of the pipes and the
pipe connections of the outdoor unit. Do not apply refrigeration oil on screw
threads. Excessive tightening torque will result in damage on the screw.
2) Align the center of the pipe with that of the pipe connections of the outdoor unit,
then hand tighten the flare nut 3 to 4 turns.
3) Tighten the flare nut with a torque wrench as specified in the table.
• Over-tightening may cause damage to the flare nut, resulting in refrigerant
leakage.
• Be sure to wrap insulation around the piping. Direct contact with the bare piping
may result in burns or frostbite.
3-4. INSULATION AND TAPING
1) Cover piping joints with pipe cover.
2) For outdoor unit side, surely insulate every piping including valves.
3) Using piping tape (E), apply taping starting from the entry of outdoor unit.
• Stop the end of piping tape (E) with tape (with adhesive agent attached).
• When piping have to be arranged through above ceiling, closet or where the
temperature and humidity are high, wind additional commercially sold insula
-
tion to prevent condensation.
3-3. PIPE CONNECTION
• The connected pipe size differs depending the models and the capacities of
indoor units.
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