Flaring Work And Pipe Connection - Mitsubishi Electric MXZ-2B20NA Installation Manual

3. FLARING WORK AND PIPE CONNECTION

3-1. FLARING WORK
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)
• Put the end of the copper pipe to downward direction as you
remove burrs in order to avoid to let burrs drop in the piping.
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
you use.
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.
Pipe diameter Nut
[mm (inch)] (mm)
ø6.35 (1/4)
ø9.52 (3/8)
ø12.7 (1/2)
ø15.88 (5/8)
3-2. PIPE CONNECTION
• Fasten flare nut with a torque wrench as specified in the table.
• When fastened too tight, flare nut may brake after a long period and
cause refrigerant leakage.
Outdoor unit connection
Connect pipes to stop valve pipe joint of the outdoor unit in the same
manner applied for indoor unit.
• For tightening, use a torque wrench or spanner and use the same
tightening torque applied for indoor unit.
When installing the unit, securely connect the refrigerant
pipes before starting the compressor.
3-3. 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 at-
tached).
• When piping have to be arranged through above ceiling, closet or
where the temperature and humidity are high, wind additional com-
mercially sold insulation to prevent condensation.
6
Clutch type tool
for R410A
17
22
0 to 0.5
(0. to 0.02)
26
29
WARNING
Copper pipe
Burr
Spare reamer
Die
Flare nut
A [mm (inch)]
Clutch type tool Wing nut type tool
for R22 for R22
1.5 to 2.0
(0.06 to 0.08)
1.0 to 1.5
(0.04 to 0.06)
2.0 to 2.5
(0.08 to 1.0)
No good
Good
Copper
pipe
Tilted Uneven Burred
Fig. 1
Flaring tool
Pipe cutter
Wing nut type
Clutch type
Fig. 3
Smooth all
around
Copper pipe
Fig. 5
Tightening torque
N•m kgf•cm
13.7 to 17.7 140 to 180
34.3 to 41.2 350 to 420
49.0 to 56.4 500 to 575
73.5 to 78.4 750 to 800
Fig. 2
Fig. 4
Inside is shin-
ing without any
scratches.
Even length
all around
Fig. 6
ft·Ib
10 to 13
25 to 30
36 to 42
54 to 58