Refrigerant Piping - Daikin FTXS20DVMW Installation Manual

Refrigerant piping work
2.

Refrigerant piping.

1) 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.
• Use torque wrenches when tightening the flare nuts to
prevent damage to the flare nuts and escaping gas.
Coat here with refrigeration machine oil
2) To prevent gas leakage, apply refrigeration machine oil on
both inner and outer surfaces of the flare. (Use refrigeration oil for R410A)
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.
(Bending radius should be 30 to 40 mm or larger.)
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 0.052 kW/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 dimen-
sions as below.
Gas side
25/35 class
O.D. 9.5mm
Thickness 0.8mm
3) Use separate thermal insulation pipes for gas and liquid refrigerant pipes.
11
Torque wrench
Spanner
Piping union
Flare nut
Gas pipe thermal
insulation
Liquid side
25/35 class
O.D. 6.4mm I.D. 12-15mm
Thickness 0.8mm
Flare nut tightening torque
Gas side
3/8 inch
l
32.7-39.9N
l
(333-407kgf
Rain
Liquid pipe
thermal insulation
I.D. 8-10mm
Thickness 10mm Min.
Liquid side
1/4 inch
l
m 14.2-17.2N m
l
cm) (144-175kgf cm)
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 wiring
Gas pipe
Gas pipe Liquid pipe
insulation insulation
Finishing tape
Drain hose
IEnglish
Wall
Liquid pipe