Flaring Work And Pipe Connection - Mitsubishi Electric MXZ-3HA50VF2 Installation Manual

3. FLARING WORK AND PIPE CONNECTION

3-1. PRECAUTIONS FOR DEVICES THAT USE R32 REFRIGERANT
• U se 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.
When installing, relocating, or servicing the unit, make sure that no substance other than the specified refrigerant (R32) enters the refrigerant
circuit.
Any presence of foreign substance such as air can cause abnormal pressure rise and may result in explosion or injury. The use of any refriger-
ant other than that specified for the system will cause mechanical failure, 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
• D o not use pipes thinner than those specified above.
• U se 1/2 H or H pipes if the diameter is 19.05 mm or larger.
• B e 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.
3-2. 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)
• 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.
Clutch
Pipe diameter Nut
type tool
(mm) (mm)
for R32,
R410A
ø6.35 (1/4") 17
ø9.52 (3/8") 22
0 to 0.5
ø12.7 (1/2") 26
ø15.88 (5/8") 29
3-3. PIPE CONNECTION
• The connected pipe size differs depending the models and the capacities of
indoor units.
Indoor unit capacity
Indoor unit: M series
• Use tightening torque table above as a guideline for indoor unit side union
joint section, and tighten using two wrenches. Excessive tightening dam-
ages the flare section.
1) Do not apply refrigeration oil on screw threads. Excessive tightening torque
will result in damage on the screw.
2) For connection, first align the center, then tighten the first 3 to 4 turns of
flare nut by hand.
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 refriger-
ant 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
insulation to prevent condensation.
En-8
0.8 0.8 1.0 1.0 1.0
A (mm) Tightening torque
Clutch Wing nut
type tool type tool N•m
for R22 for R22
13.7 to 17.7 140 to 180
1.5 to 2.0
34.4 to 41.2 350 to 420
1.0 to 1.5
49.1 to 56.9 500 to 580
2.0 to 2.5
73.5 to 78.5 750 to 800
Liquid pipe size
Gas pipe size
WARNING
1.0 1.0
Copper pipe
Burr
Spare reamer
kgf•cm
Die
Flare nut
WARNING
25 ~ 50
When installing the unit, securely
connect the refrigerant pipes before
ø6.35
starting the compressor.
ø9.52
CAUTION
When there are the ports which are
not used, make sure their nuts are
tightened securely.
Indoor unit connection
Flare nut
Internal thread side
Tighten the flare nut
with a torque wrench.
Outdoor unit connection
Good No good
Copper
pipe
Tilted Uneven Burred
Fig. 1
Flaring tool
Pipe cutter
Clutch type Wing nut type
Fig. 3
Inside is shin-
Smooth all
ing without any
around
scratches.
Copper pipe
Fig. 5
Union joint
External thread side
Grip the nut on the
union joint with a spanner.
Tighten the flare nut
with a torque wrench.
Fig. 2
Fig. 4
Even length
all around
Fig. 6