Refrigerant Piping Work; Flaring The Pipe End; Refrigerant Piping - Daikin FTX-N/U Manual

FTX-N/U, FVXS-N, FDMQ-R Series
01_EN_3P572321-1A.fm Page 8 Thursday, August 8, 2019 10:47 AM

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 this 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.
Cut exactly at
right angles.
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.
Do not apply refrigeration
oil to the outer surface.
Flare nut
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.
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.
Gas side
Liquid side
• Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
• Using finishing tape, bundle and wrap the indoor unit piping and drain hose together so that the drain hose is below the other
piping.
Remove burrs.
Apply oil
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.
Piping size Minimum bend radius
O.D. 1/2 inch
(12.7mm)
1-15/16 inch (50mm)
or more
O.D. 5/8 inch
(15.9mm)
O.D. 1/4 inch 1-3/16 inch (30mm)
(6.4mm) or more
Set exactly at the position shown below.
Flare tool for
A
R410A
Clutch-type
0-0.020 inch
Die
A
(0-0.5mm)
The flare's inner surface must be
flaw-free.
When flaring, do not over-tighten
and crack.
Tighten
Torque wrench
Spanner
Gas side
Piping union
Flare nut Liquid side
Rain
Piping thickness Thermal insulation size
I.D. 9/16-5/8 inch
(14-16mm)
0.039 inch (1.0mm)
(C1220T-O)
I.D. 5/8-13/16 inch
(16-20mm)
0.031 inch (0.8mm) I.D. 5/16-13/32 inch
(C1220T-O) (8-10mm)
90
Flaring
Conventional flare tool
Clutch-type Wing-nut type
(Rigid-type) (Imperial-type)
0.039-0.059 inch 0.059-0.079 inch
(1.0-1.5mm) (1.5-2.0mm)
Check
The pipe end must be evenly flared
in a perfect circle.
Make sure that the flare nut is fitted.
Flare nut tightening
Piping size
torque
O.D. 1/2 inch 36-1/2–44-1/2ft • lbf
(12.7mm) (49.5-60.3N • m)
O.D. 5/8 inch 45-5/8–55-5/8ft • lbf
(15.9mm) (61.8-75.4N • m)
O.D. 1/4 inch 10-1/2–12-3/4ft • lbf
(6.4mm) (14.2-17.2N • m)
Be sure to
Wall
place a cap.
If no flare cap is
available, cover the
flare mouth with
tape to keep dirt
and water out.
Gas pipe Liquid pipe
Gas pipe Liquid pipe
insulation insulation
Finishing tape Drain hose
Thermal insulation thickness
13/32 inch
(10mm) Min.
3P572321-1A
EDUS091558E
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