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4. PIPE INSTALLATION - 1
4. 1. Flare connection (pipe connection)
CAUTION
Do not use mineral oil on a flared part. Prevent mineral oil from getting into the system
as this would reduce the lifetime of the units.
While welding the pipes, be sure to blow dry nitrogen gas through them.
The maximum lengths of this product are shown in the table. If the units are further
apart than this, correct operation cannot be guaranteed.
Flaring
• Use special pipe cutter and flare tool exclusive for R410A.
(1) Cut the connection pipe to the necessary length with a pipe cutter.
(2) Hold the pipe downward so that the cuttings will not enter the pipe and remove
any burrs.
(3) Insert the flare nut (always use the flare nut attached to the indoor and outdoor
units respectively) onto the pipe and perform the flare processing with a flare tool.
Leakage of refrigerant may result if other flare nuts are used.
(4) Protect the pipes by pinching them or with tape to prevent dust, dirt, or water from
entering the pipes.
L
Check if [L] is flared uniformly
and is not cracked or scratched.
Pipe
A
B
Die
Pipe outside
diameter [in. (mm)]
Dimension A [in. (mm)]
Dimension B
0
- 0.4
[in. (mm)]
Flare tool for R410A,
clutch type
1/4 (6.35)
0 to 0.020 (0 to 0.5)
3/8 (9.1)
3/8 (9.52)
1/2 (13.2)
1/2 (12.70)
5/8 (16.6)
5/8 (15.88)
3/4 (19.7)
3/4 (19.05)
15/16 (24.0)
• When using conventional flare tools to flare R410A pipes, the dimension A should
be approximately 0.020 in. (0.5 mm) more than indicated in the table (for flaring
with R410A flare tools) to achieve the specified flaring. Use a thickness gauge to
measure the dimension A.
Pipe outside
diameter
[in. (mm)]
Width across flats
of Flare nut
[in. (mm)]
1/4 (6.35)
11/16 (17)
3/8 (9.52)
7/8 (22)
1/2 (12.70)
1 (26)
5/8( 15.88)
1-1/8 (29)
3/4 (19.05)
1-7/16 (36)
Width across flats
4. 1. 1. Bending pipes
CAUTION
To prevent breaking of the pipe, avoid sharp bends. Bend the pipe with a radius of
curvature of 4 in. (100 mm) or more.
If the pipe is bent repeatedly at the same place, it will break.
•
If pipes are shaped by hand, be careful not to collapse them.
• Do not bend the pipes at an angle of more than 90°.
• When pipes are repeatedly bent or stretched, the material will harden, making it
difficult to bend or stretch them any more.
• Do not bend or stretch the pipes more than 3 times.
4. 1. 2. Pipe connection
CAUTION
Be sure to install the pipe against the port on the indoor unit and the outdoor unit
correctly. If the centering is improper, the flare nut cannot be tightened smoothly.
If the flare nut is forced to turn, the threads will be damaged.
Do not remove the flare nut from the outdoor unit pipe until immediately before
connecting the connection pipe.
After installing the piping, make sure that the connection pipes do not touch the
compressor or outer panel. If the pipes touch the compressor or outer panel, they will
vibrate and produce noise.
(1) Detach the caps and plugs from the pipes.
(2) Center the pipe against the port on the outdoor unit, and then turn the flare nut
by hand.
To prevent gas leakage, coat the flare
surface with alkylbenzene oil (HAB).
Do not use mineral oil.
(3) Attach the connection pipe.
Flare nut
Connection pipe
(Liquid)
Connection pipe
(Gas)
Flare nut
3-way valve (Gas)
2-way valve
(Liquid)
(4) When the flare nut is tightened properly by your hand, use a torque wrench to
finally tighten it.
Holding wrench
Connection pipe
Torque wrench
Body side
CAUTION
Hold the torque wrench at its grip, keeping it in a right angle with the pipe, in order to
tighten the flare nut correctly.
• Outer panel may be distorted if fastened only with a wrench. Be sure to fix the
elementary part with a holding wrench and fasten with a torque wrench (refer to below
diagram). Do not apply force to the blank cap of the valve or hang a wrench, etc., on the
cap. If blank cap is broken, it may cause leakage of refrig
erant.
Flare nut [in. (mm)]
Tightening torque [lbf·ft. (N·m)]
1/4 (6.35) dia.
11.8 to 13.3 (16 to 18)
3/8 (9.52) dia.
23.6 to 31.0 (32 to 42)
1/2 (12.70) dia.
36.1 to 45.0 (49 to 61)
5/8 (15.88) dia.
46.5 to 55.3 (63 to 75)
3/4 (19.05) dia.
66.4 to 81.1 (90 to 110)
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2014/12/19 14:57:18
