Caution On Piping Handling; Selection Of Copper And Heat Insulation Materials; Refrigerant Piping - Daikin R410A Split Series Installation Manual

Refrigerant Piping Work
2.

Refrigerant piping

CAUTION
• Use the flare nut fixed to the main unit. (To prevent cracking of the flare nut by aged deterioration.)
• To prevent gas leakage, apply refrigeration oil only to the inner surface of the flare. (Use refrigeration oil for R410A.)
• Use torque wrenches when tightening the flare nuts to prevent damage to the flare nuts and gas leakage.
Align the centres of both flares and tighten the flare nuts 3 or 4 turns by hand. Then tighten them fully with the torque wrenches.

2-1. Caution on piping 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.

2-2. 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
dimensions as below.
20/25/35/42 class
O.D. 9.5mm
30mm or more
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
7
[Apply oil]
Do not apply refrigeration
oil to the outer surface.
Flare nut
Do not apply refrigeration
oil to the flare nut avoid
tightening with over torque.
Gas side
20/25/35/42 class
3/8 inch
32.7-39.9N m
(330-407kgf cm)
Gas side
50 class
O.D. 12.7mm
Minimum bend radius
40mm or more
Thickness 0.8mm (C1220T-O)
Apply refrigeration oil to
the inner surface of the
flare.
Flare nut tightening torque
50 class
1/2 inch
49.5-60.3N m 14.2-17.2N m
(505-615kgf cm) (144-175kgf cm)
Liquid side Gas pipe thermal insulation
20/25/35/42 class
O.D. 6.4mm
I.D. 12-15mm
30mm or more
[Tighten]
Torque wrench
Spanner
Piping union
Flare nut
Liquid side
1/4 inch
Be sure to
place a cap.
Rain
If no flare cap is
available, cover the
flare mouth with
tape to keep dirt or
water out.
Gas pipe
Gas pipe
insulation
Finishing tape
50 class
I.D. 14-16mm
Thickness 10mm Min.
Wall
Inter-unit wire
Liquid pipe
Liquid pipe
insulation
Drain hose
Liquid pipe
thermal insulation
I.D. 8-10mm
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