Refrigerant Piping; Caution On Piping Handling; Selection Of Copper And Heat Insulation Materials - Daikin FTXN15KVJU Installation Manual

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 centers of both flares and tighten the flare nuts 3 or 4 turns by hand. Then tighten them fully with the torque
wrenches.
Flare nut
Do not apply refrigeration
oil to the flare nut avoid
tightening with over torque.

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 (0.024 to 0.030Btu/fth°F (0.035 to
0.045kcal/mh°C))
Refrigerant gas pipe's surface temperature reaches 230°F (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. 1/2 inch (12.7mm)
1-9/16 inch (40mm) or more 1-3/16 inch (30mm) or more
Thickness 0.031 inch (0.8mm) (C1220T-O)
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
■English
[Apply oil]
Do not apply refrigeration
oil to the outer surface.
Flare nut tightening torque
Gas side
1/2 inch (12.7 mm)
36.5-44.5ft • lbf
(49.5-60.3N • m)
Liquid side
O.D. 1/4 inch (6.4mm)
Minimum bend radius
Apply refrigeration oil to
the inner surface of the
flare.
Spanner
Piping union
Liquid side
1/4 inch (6.4mm)
10.4-12.7ft lbf
(14.2-17.2N m)
Rain
Gas pipe thermal
insulation
I.D. 0.551-0.630 inch
(14-16mm)
Thickness 0.393 inch (10mm) Min.
[Tighten]
Torque wrench
Flare nut
Be sure to
place a cap.
If no flare cap is
available, cover
the flare mouth
with tape to keep
dirt or water out.
Inter-unit wire
Gas pipe
Gas pipe
insulation
Finishing tape
Liquid pipe thermal
insulation
I.D. 0.315-0.393 inch
(8-10mm)
Wall
Liquid pipe
Liquid pipe
insulation
Drain hose
7