Piping Works And Flaring Technique
Do not use contaminated or damaged copper tubing. If any
piping, evaporator or condenser had been exposed or had
been opened for 15 seconds or more, the system must be
vacuumed. Generally, do not remove plastic, rubber plugs
and brass nuts from the valves,
Þ
ttings, tubings and coils
until it is ready for connection.
If any brazing work is required, ensure that the nitrogen
gas is passed through piping and joints while the brazing
work is being done. This will eliminate soot formation on
the inside walls of the copper tubings.
Cut the pipe stage by stage, advancing the blade of pipe
cutter slowly. Extra force and deep cut will cause more
distortion of pipe and therefore extra burr. See Fig. A
Remove burrs from cut edges of pipes with a remover as
shown in Fig. B. This will avoid unevenness on the
ß
are
faces which will cause gas leak. Hold the pipe on top
position and burr remover at lower position to prevent
metal chips from entering the pipe.
Insert the
ß
are nuts mounted on the connection parts of both
indoor and outdoor unit, into the copper pipes.
The exact length of pipe protruding from the face of the
swaging block is determined by the
ß
aring tool. See Fig. C
Fix the pipe
Þ
rmly on the swaging block. Match the centers
of both the
ß
are die and the
ß
aring punch, and tighten
ß
aring punch fully.
•
•
•
•
•
•
•
1/4t
Cutting Copper Tube
Copper Tube
Swaging Block
Piping Connection To The Units
Align the center of the piping and suf
Þ
ciently tighten the
ß
are nut with
Þ
ngers. See Fig. D
Finally, tighten the
ß
are nut with torque wrench until the
wrench clicks.
When tightening the
ß
are nut with the torque wrench,
ensure that the direction for tightening follows the arrow
on the wrench.
The refrigerant pipe connection are insulated by closed
cell polyurethane.
•
•
•
•
Fig. B
Remove Burr
Copper Tube
Fig. A
Fig. C
Fig. D
Flared Tube
Flare Joint
Flare Nut
Indoor Piping
Torque Wrench
Spanar
Pipe Size, mm (in)
Torque, Nm / (ft-Ib)
6.35 (1/4")
18 (13.3)
9.52 (3/8")
42 (31.0)
12.70 (1/2")
55 (40.6)
15.88 (5/8")
65 (48.0)
19.05 (3/4")
78 (57.6)
Ø Tube, D
A (mm)
Inch
mm
Imperial
(Wing-nut Type)
Rigid
(Clutch Type)
1/4"
6.35
1.3
0.7
3/8"
9.52
1.6
1.0
1/2"
12.70
1.9
1.3
5/8"
15.88
2.2
1.7
3/4"
19.05
2.5
2.0
D
A
