Flaring Work; Pipe Connection - Mitsubishi Electric MLZ-KP25VF Manual De Instalación

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)
• 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.
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

• In case of reconnecting the refrigerant pipes after detaching, make the
flared part of pipe re-fabricated.
• 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.
• Be sure to wrap insulation around the piping. Direct contact with the
bare piping may result in burns or frostbite.
Indoor unit connection
Connect both liquid and gas pipings to indoor unit.
• Apply a thin coat of refrigeration oil 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 wrenches. 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.
3-4. INSTALLING THE PIPE COVER
Make sure to install the pipe cover. Incorrect installation results in water
leakage.
• No insulation is needed on the pipe connecting part of the indoor side
for this unit. The pipe cover gathers the water condensed around the
pipe connecting part.
1) Install the pipe band removed in 3-1. to secure the connecting pipes.
* The pipe band should hold down the insulating material of connecting
pipe. Insulating material should protrude 10 mm or more than the pipe
band, as shown in the illustration on the right.
2) Install pipe cover.
When using pipe with super insulating material
(about ø48 mm liquid pipe, ø51 mm gas pipe)
1) Make sure that the plate is turned over, and the concave part is facing
upward. (Refer to 3-1.)
2) Use band provided with the unit. (Do not use the pipe band attached
to the unit)
3) Connecting pipe exit of pipe cover is precut. Cut it along the line.
4) Install pipe cover.
Note:
Install pipe cover and pipe band securely. Incomplete installation will
cause water to drip from the unit, soaking and damaging household goods.
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
34.3 to 41.2 350 to 420
1.0 to 1.5
2.0 to 2.5 49.0 to 56.4 500 to 575
- 73.5 to 78.4 750 to 800
Copper
pipe
Fig. 1
Copper pipe
Burr
Spare reamer
Pipe cutter
Fig. 3
A
kgf•cm
Copper pipe
Die
Flare nut
Fig. 5
When installing the unit, securely connect the refrigerant
pipes before starting the compressor.
Reusable mechanical connectors and flared joints are
not allowed indoors.
When connecting the refrigerant piping by brazing,
rather than using flare connections, complete all brazing
prior to connecting indoor unit to outdoor unit.
Insulating material
should protrude 10
mm or more than
the edge of pipe
band
[When using pipe with super
insulating material]
Insulating material
should protrude 10
mm or more than
the edge of pipe
Band
band
Fixing screw
No good
Good
90°
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
WARNING
WARNING
Pipe band
Insulating material
should protrude 10 mm
or more than the edge
of pipe band
Pipe cover
(accessory part)
Fixing screw
Insulating material
should protrude 10 mm
Cut
or more than the edge
of pipe band
Pipe cover
En-8