9 nEnglish
Refrigerant Piping Work
Precautions for Laying Refrigerant Piping
• Cautions on pipe handling
1) Protect the open end of the pipe against dust and moisture.
2) 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:
1) Insulation material: Polyethylene foam
Heat transfer rate: 0.041 to 0.052W/mK (0.035 to 0.045kcal/mh°C)
Refrigerant gas pipe’s surface temperature reaches 110°C max.
Choose heat insulation materials that will withstand this temperature.
2) Be sure to insulate both the gas and liquid piping and to provide insulation dimen-
sions as below.
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
• Flaring the pipe end
1) Cut the pipe end with a pipe cutter.
2) Remove burrs with the cut surface facing down-
ward so that the chips do not enter the pipe.
3) Put the flare nut on the pipe.
4) Flare the pipe.
5) Check that the flaring is properly made.
• Do not use mineral oil on flared part.
• Prevent mineral oil from getting into the system as this would reduce the lifetime 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 lifetime.
• The drying material may dissolve and damage the system.
• Incomplete flaring may cause refrigerant gas leakage.
Gas pipe Liquid pipe
Gas pipe
insulation
Liquid pipe
insulation
O.D.9.5mm O.D.12.7mm O.D.6.4mm I.D.12-15mm I.D.8-10mm
Minimum bend radius
Thickness
13mm min.
Thickness
10mm min.
30mm or
more
40mm or
more
30mm or
more
Thickness 0.8mm (C1220T-O)
Wall
If no flare cap is
available, cover
the flare mouth
with tape to keep
dirt or water out.
Be sure to
place a cap.
Rain
Gas pipe
Liquid pipe
Gas pipe
insulation
Liquid pipe
insulation
Finishing tape
Drain hose
Inter-unit wires
(Cut exactly at
right angles.) Remove burrs
Set exactly at the position shown below.
A
Flaring
Die
Check
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.
A 0-0.5mm
Clutch-type
Flare tool for R410A
1.0-1.5mm
Clutch-type (Rigid-type)
1.5-2.0mm
Wing-nut type (Imperial-type)
Conventional flare tool