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Refrigerant Piping Work
WARNING
• Do not apply mineral oil on flared part.
• Prevent mineral oil from getting into the system as this would reduce the service life of the units.
• Never use piping which has been used for previous installations. Only use parts which are delivered with the unit.
• Never install a dryer to this R410A unit in order to guarantee its service life.
• The drying material may dissolve and damage the system.
• Incomplete flaring may result in refrigerant gas leakage.
1.
Flaring the pipe end
1) Cut the pipe end with a pipe cutter.
2) Remove burrs with the cut surface facing downward
so that the filings do not enter the pipe.
3) Put the flare nut on the pipe.
4) Flare the pipe.
5) Check that the flaring has been done correctly.
2.
Refrigerant piping
CAUTION
• Use the flare nut fixed to the main unit. (This is to prevent the flare nut from cracking as a result of deterioration over time.)
• To prevent gas leakage, apply refrigeration oil only to the inner surface of the flare. (Use refrigeration oil for R410A.)
• Use a torque wrench when tightening the flare nuts to prevent damage to the flare nuts and gas leakage.
• Align the centers of both flares and tighten the flare nuts 3 or 4 turns by hand, then tighten them fully with a spanner and a torque wrench.
2-1. Caution on piping handling
• Protect the open end of the pipe against dust and moisture.
• All pipe bends should be as gentle as possible. Use a pipe bender for
bending.
2-2. Selection of copper and heat insulation materials
When using commercial copper pipes and fittings, observe the following:
• Insulation material: Polyethylene foam
Heat transfer rate: 0.041 to 0.052W/mK (0.024 to 0.030Btu/fth°F (0.035 to
0.045kcal/mh°C))
Be sure to use insulation that is designed for use with HVAC Systems.
• ACR Copper only.
• Be sure to insulate both the gas and liquid piping and observe the insulation dimensions as below.
• Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
Piping size
Minimum bend radius
Piping thickness
Thermal insulation size
Thermal insulation
thickness
Gas side
O.D. 5/8 inch
(15.9mm)
1-15/16 inch (50mm)
or more
0.039 inch (1.0mm)
(C1220T-O)
I.D. 5/8-13/16 inch
(16-20mm)
13/32 inch
(10mm) Min.
Liquid side
O.D. 1/4 inch
(6.4mm)
1-3/16 inch (30mm)
or more
0.031 inch (0.8mm)
(C1220T-O)
I.D. 5/16-13/32 inch
(8-10mm)
A
A
Flaring
Set exactly at the position shown below.
Die
0-0.020 inch
(0-0.5mm)
Clutch-type
Flare tool for
R410A
0.039-0.059 inch
(1.0-1.5mm)
Clutch-type
(Rigid-type)
0.059-0.079 inch
(1.5-2.0mm)
Wing-nut type
(Imperial-type)
Conventional flare tool
The flare’s inner surface must be
flaw-free.
The pipe end must be evenly flared
in a perfect circle.
Make sure that the flare nut is fitted.
Check
Cut exactly at
right angles.
Remove burrs.
Do not apply refrigeration
oil to the outer surface.
Flare nut
Apply refrigeration
oil only to the inner
surface of the flare.
Do not apply refrigeration
oil to the flare nut to avoid
tightening with excessive
torque.
Apply oil
Torque wrench
Piping union
Flare nut
Spanner
Tighten
Piping size
O.D. 5/8 inch
(15.9mm)
Gas side
Liquid side
O.D. 1/4 inch
(6.4mm)
Flare nut tightening
torque
45-5/8–55-5/8ft • lbf
(61.8-75.4N • m)
10-1/2–12-3/4ft • lbf
(14.2-17.2N • m)
Wall
If no flare cap is
available, cover the
flare mouth with
tape to keep dirt
and water out.
Rain
Be sure to
place a cap.
Gas pipe
Liquid pipe
Gas pipe
insulation
Liquid pipe
insulation
Finishing tape Drain hose
01_EN_3P457790-1.fm Page 8 Thursday, December 1, 2016 3:51 PM
