Daikin CTXU25G2V1B Service Manual page 53

Installation Manual
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 0.045kcal/(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.
25/35/42 class
O.D. 9.5mm
30mm or more
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
7
50
[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.
Flare nut tightening torque
Gas side
25/35/42 class
3/8 inch
32.7-39.9N m • 49.5-60.3N m
(330-407kgf cm) • (505-615kgf cm)
Gas side
Liquid side
50 class
O.D. 12.7mm O.D. 6.4mm
Minimum bend radius
40mm or more 30mm or more
Thickness 0.8mm (C1220T-O)
Apply refrigeration oil to
Torque wrench
the inner surface of the
flare.
Spanner
Piping union
Flare nut
Liquid side
50 class
1/2 inch 1/4 inch
• 14.2-17.2N m •
• (144-175kgf cm) •
Rain
Gas pipe thermal insulation
25/35/42 class
I.D. 12-15mm
Thickness 10mm Min.
[Tighten]
Wall
Be sure to
place a cap.
If no flare cap is
available, cover the
flare mouth with
tape to keep dirt or
water out.
Finishing tape
Inter-unit wiring
Gas pipe
Drain hose
Gas pipe
insulation
Humidifying
hose
Liquid pipe insulation Liquid pipe
Liquid pipe
thermal insulation
50 class
I.D. 14-16mm I.D. 8-10mm
Installation / Operation Manual
SiBE12-908