Daikin ATX35J2V1B Installation Manual page 15

Refrigerant Piping Work
2.
Refrigerant piping.
CAUTION
1) Use the flare nut fixed to the main unit. (To prevent cracking of the flare nut by aged deterioration.)
2) To prevent gas leakage, apply refrigeration oil only to the inner surface of the flare. (Use refrigeration oil for R410A.)
3) 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 0.045 kcal/(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.
Gas side
O.D. 9.5mm
Minimum bend radius
Thickness 0.8mm (C1220T-O)
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
English
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.
(330-407kgf • cm)
Liquid side
O.D. 6.4mm
30mm or more
[Apply oil]
Apply refrigeration oil to
the inner surface of the
flare.
Flare nut tightening torque
Gas side Liquid side
3/8 inch 1/4 inch
32.7-39.9N • m 14.2-17.2N • m
(144-175kgf • cm)
Gas pipe thermal
insulation
I.D. 12-15mm
Thickness 10mm Min.
[Tighten]
Torque wrench
Spanner
Piping union
Flare nut
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
Liquid pipe thermal
insulation
I.D. 8-10mm
Wall
Inter-unit wiring
Liquid pipe
Liquid pipe
insulation
Drain hose
11