Refrigerant Piping - Daikin R410A Split Series Installation Manual

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
Do not apply refrigeration oil to
the flare nut to avoid tightening
with excessive torque.
Gas side
Liquid side
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.
Gas side
Liquid side
• Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
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English
Apply oil
Apply refrigeration
oil only to the inner
surface of the flare.
Piping size
O.D. 3/8 inch (9.5mm)
O.D. 1/2 inch (12.7mm)
O.D. 1/4 inch (6.4mm)
Piping size Minimum bend radius
O.D. 3/8 inch 1-3/16 inch (30mm)
(9.5mm) or more
O.D. 1/2 inch 1-9/16 inch (40mm)
(12.7mm) or more
O.D. 1/4 inch 1-3/16 inch (30mm)
(6.4mm) or more
Tighten
Torque wrench
Spanner
Piping union
Flare nut
Flare nut tightening torque
24-1/8–29-1/2ft • Ibf (32.7-39.9N • m)
36-1/2–44-1/2ft • lbf (49.5-60.3N • m)
10-1/2–12-3/4ft • lbf (14.2-17.2N • m)
Rain
Gas pipe
insulation
Piping thickness Thermal insulation size
I.D. 15/32-19/32 inch
(12-15mm)
0.031 inch (0.8mm) I.D. 9/16-5/8 inch
(C1220T-O) (14-16mm)
I.D. 5/16-13/32 inch
(8-10mm)
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
Liquid pipe
insulation
Finishing tape Drain hose
Thermal insulation
thickness
13/32 inch
(10mm) Min.
10