Flaring Work And Pipe Connection - Mitsubishi Electric MXZ-3A30NA Manual De Instalación

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) 17
ø9.52 (3/8) 22
ø12.7 (1/2) 26
ø15.88 (5/8) 29
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.
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.
A [mm (inch)]
Clutch type tool Clutch type tool
for R410A for R22
0 to 0.5 1.0 to 1.5
(0. to 0.02) (0.04 to 0.06)
Good
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
Smooth all
around
Copper pipe
Die
Flare nut
Fig. 5
Tightening torque
Wing nut type tool
N•m
for R22
13.7 to 17.7
1.5 to 2.0
(0.06 to 0.08)
34.3 to 41.2
49.0 to 56.4
2.0 to 2.5
(0.08 to 1.0)
73.5 to 78.4
No good
Tilted Uneven Burred
Fig. 2
Flaring tool
Clutch type Wing nut type
Fig. 4
Inside is shin-
ing without any
scratches.
Even length
all around
Fig. 6
kgf•cm ft·Ib
140 to 180 10 to 13
350 to 420 25 to 30
500 to 575 36 to 42
750 to 800 54 to 58
7