Flaring Work - Mitsubishi Electric Mr.SLIM SUZ-SA71VA3 Manuel D'installation

4. Refrigerant piping work
90°
Fig. 4-3
Fig. 4-4
Fig. 4-5
A
Fig. 4-6
B
Fig. 4-7
Fig. 4-8
4

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)
Copper tubes
a
• Using a pipe cutter cut the copper tube correctly.
b Good
c No good
4.2.2. Burrs removal (Fig. 4-4)
Tilted
d
• Completely remove all burrs from the cut cross section of pipe/tube.
e Uneven
f Burred • 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)
a Burr
• Remove fl are nuts attached to indoor and outdoor unit, then put them on pipe/tube
b Copper tube/pipe
having completed burr removal.
Spare reamer
c (not possible to put them on after fl aring work)
d Pipe cutter
4.2.4. Flaring work (Fig. 4-6)
• Carry out fl aring work using fl aring tool as shown at the right.
Pipe diameter
Flare nut
a
(mm)
b Copper tube
9.52
15.88
Firmly hold copper tube in a die in the dimension shown in the table at above.
Flaring tool
a
b Die
c Copper tube
Flare nut
d
e Yoke
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
b Inside is shining without any scratches
Even length all around
c
Too much
d
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.
ø15.88
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.
Dimension
A (mm)
When the tool for R410A is used
Clutch type
0 - 0.5
0 - 0.5
f
g
h
i
Flare nut O.D.
(mm) (mm)
ø9.52 22
29
+0
(mm)
B
-0.4
13.2
19.7
Scratch on fl ared plane
Cracked
Uneven
Bad examples
Tightening torque
(N·m)
34 - 42
68 - 82