4
/
2
1
0
3
4
90°
2
1
0
/
0
/
/
0
3
0
1
2
1
A
4. Refrigerant piping work
Fig. 4-3
4.2. Flaring work
• Main cause of gas leakage is defect in
fl
aring work.
Carry out correct
fl
aring work in the following procedure.
4.2.1. Pipe cutting (Fig. 4-3)
• Using a pipe cutter cut the copper tube correctly.
4.2.2. Burrs removal (Fig. 4-4)
• Completely remove all burrs from the cut cross section of pipe/tube.
• Put the end of the copper tube/pipe to downward direction as you remove burrs in
order to avoid burrs drop in the tubing.
4.2.3. Putting nut on (Fig. 4-5)
• Remove
fl
are nuts attached to indoor and outdoor unit, then put them on pipe/tube
having completed burr removal.
(not possible to put them on after
fl
aring work)
4.2.4. Flaring work (Fig. 4-6)
• Carry
out
fl
aring work using
fl
aring tool as shown at the right.
Pipe diameter
(mm)
Dimension
A (mm)
B
+0
(mm)
-0.4
When the tool for R410A is used
Clutch type
9.52
0 - 0.5
13.2
15.88
0 - 0.5
19.7
Firmly hold copper tube in a die in the dimension shown in the table at above.
4.2.5. Check (Fig. 4-7)
• Compare
the
fl
ared work with a
fi
gure in right side hand.
• If
fl
are is noted to be defective, cut off the
fl
ared section and do
fl
aring work again.
a
Smooth all around
f
Scratch on
fl
ared plane
b
Inside is shining without any scratches
g
Cracked
c
Even length all around
h
Uneven
d
Too much
i
Bad examples
e
Tilted
• Apply a thin coat of refrigeration oil on the seat surface of pipe. (Fig. 4-8)
• For connection
fi
rst align the center, then tighten the
fi
rst 3 to 4 turns of
fl
are nut.
• Use tightening torque table below as a guideline for indoor unit side union joint
section, and tighten using two wrenches. Excessive tightening damages the
fl
are
section.
Copper pipe O.D.
(mm)
Flare nut O.D.
(mm)
Tightening torque
(N·m)
ø9.52
22
34 - 42
ø15.88
29
68 - 82
Warning:
When installing the unit, securely connect the refrigerant pipes before starting
the compressor.
Warning:
Be careful of
fl
ying
fl
are nut! (Internally pressurized)
Remove the
fl
are nut as follows:
1. Loosen the nut until you hear a hissing noise.
2. Do not remove the nut until the gas has been completely released (i.e., hiss-
ing noise stops).
3. Check that the gas has been completely released, and then remove the nut.
Fig. 4-4
Fig. 4-5
Fig. 4-6
a
Copper tubes
b
Good
c
No good
d
Tilted
e
Uneven
f
Burred
a
Burr
b
Copper tube/pipe
c
Spare reamer
d
Pipe cutter
a
Flare nut
b
Copper tube
a
Flaring tool
b
Die
c
Copper tube
d
Flare nut
e
Yoke
1
0
/
2
3
4
5
6
7
B
Fig. 4-7
Fig. 4-8
