Piping Works And Flaring Technique
•
Do not use contaminated or damaged copper tubing. If any pipings, 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, fittings, tubings and coils until it is ready to connect suction or liquid line into valves or fittings.
•
If any brazing work is required, ensure that the nitrogen gas is passed through coil 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 the pipe cutter slowly. Extra force and deep cut will cause more distortion
on the pipe and thus extra burr. See Figure A.
•
Remove burrs from cut edges of the pipes with remover
as shown in Figure B. This will avoid unevenness on the
flare 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 flare nuts, mounted on the connection parts
of both the indoor unit and outdoor unit, into the copper
pipes.
•
The exact length of pipe protruding from the top surface
of the swaging block is determined by the flaring tool.
Refer Figure C.
•
Fix the pipe firmly on the swaging block. Match the centers
of both the flare die and the flaring punch, and then tighten
the flaring punch fully.
Piping Connection To The Units
•
Align the center of the piping and tighten the flare nut
sufficiently with fingers. Refer Figure D.
•
Finally, tighten the flare nut with the torque wrench until
the wrench clicks.
•
When tightening the flare nut with the torque wrench,
ensure that the tightening direction follows the arrow
indicated on the wrench.
•
The refrigerant pipe connection are insulated by closed
cell polyurethane.
Pipe Size (mm/in)
6.35 (1/4")
9.52 (3/8")
12.70 (1/2")
15.88 (5/8")
19.05 (3/4")
Ø Tube, D
Inch
mm
(Wing-nut Type)
1/4"
6.35
3/8"
9.52
1/2"
12.70
5/8"
15.88
3/4"
19.05
Torque, Nm/(ft-lb)
18 (13.3")
42 (31.0")
55 (40.6")
65 (48.0")
78 (57.6")
A (mm)
Imperial
Rigid
(Clutch Type)
1.3
0.7
1.6
1.0
1.9
1.3
2.2
1.7
2.5
2.0
Figure A
Cutting Copper Tube
1/4t
Figure B
Remove Burr
Figure C
Copper Tube
Swaging Block
Figure D
Flare Joint
Indoor Piping
1-8
D
Flared Tube
Flare Nut
Torque Wrench
Spanar