Flaring Work And Pipe Connection - Mitsubishi Electric MFZ-KA25VA Installation Manual

2-9. FRONT PANEL INSTALLATION
1) Open the horizontal vane for the upper air outlet.
2) Fit the front panel onto the indoor unit from the front, and then push
the upper and lower areas that are marked with arrows.
3) Push the areas below the upper air outlet and the areas above and
below the lower air outlet that are marked with arrows.
4) After installing the front panel, install the 2 screws below the upper
air outlet.
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
Clutch
(mm) (mm)
type tool
for R410A
ø 6.35 (1/4") 1
ø 9.52 (3/8") 22
0 to 0.5
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 break after a long period and cause refrigerant leakage.
Indoor unit connection
Connect both liquid and gas pipings to indoor unit.
• Apply a thin coat of refrigeration oil (J) on the seat surface of pipe.
• For connection, first align the center, then tighten the first 3 to 4 turns of flare nut.
• Use tightening torque table above as a guideline for indoor unit side union joint section, and tighten using two wrench-
es. Excessive tightening damages the flare section.
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 (G), apply taping starting from the entry of outdoor unit.
• Stop the end of piping tape (G) 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
insulation to prevent condensation.
A (mm) Tightening torque
Clutch type Wing nut
tool type tool N•m
for R22 for R22
13. to 1. 140 to 180
1.5 to 2.0
34.3 to 41.2 350 to 420
1.0 to 1.5
49.0 to 56.4 500 to 575
2.0 to 2.5
73.5 to 78.4 750 to 800
WARNING
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
kgf•cm
Copper pipe
Die
Flare nut
Fig. 5
No good
Good
Tilted Uneven Burred
Fig. 2
Flaring tool
Clutch type Wing nut type
Fig. 4
Inside is shin-
ing without any
Smooth all
scratches.
around
Even length
all around
Fig. 6