Maximum Pipe Length And Maximum No. Of Bends
When the pipe length becomes too long, both the capacity and reliability will drop and as the no. of bends increases, system piping
resistance to the refrigerant flow increases, thus lowering the capacity. As a result the compressor may fail. Always choose the shortest
path and follow the recommendations as tabulated below:-
Model
Max. Length
Max. Elevation
Max. no. of Bends
Model
Max. Length
Max. Elevation
Max. no. of Bends
Bending must be carefully made so as not to crush the pipe. Use a pipe bender to bend a pipe where possible.
A
C
•
Our guarantee on the performance of our air-conditioners is strictly revoked if the height, length and/or no. of bends
of the refrigerant piping system installed is beyond the limit above.
Remark:
For cooling unit SL 60/4SL 60, recommended to add 6 kg, MSS / 4MSS 75 (6 kg) & MSS / 4MSS 100 (10 kg) external
accumulator respectively.
Piping Works & 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, then vacuum and purge with
field supplied refrigerant. 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.
•
Remove burrs from cut edges of the pipes with remover as
shown in the figure. This will avoid unevenness on the flare
faces which will cause gas leak. Hold the end of the pipe
downwards 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, onto the copper pipes.
•
The exact length of pipe protruding from the face of the flare
die is determined by the flaring tool. See figure. The table shows
the use of an imperial die and rigid die.
•
Fix the pipe firmly on the flare die. Match the centers of both
the flare die and the flaring punch, and then tighten the flaring
punch fully.
REFRIGERANT PIPING
SL/4SL/5SL & 30/35/40/50/60 C/CR
MSS 75/100 D/DR & 4MSS 75/100 D/DR
B
!
CAUTION
1-5
35m
10m
10
35m
20m
10
C
A
B
C
Cutting Copper Tube
1/4t
Copper Tube
Remove Burr
Copper Tube
D
Swaging Block
Ø Tube, D
Inch
mm
1/4"
6.35
3/8"
9.52
1/2"
12.70
5/8"
15.88
3/4"
19.05
A (mm)
Imperial
Rigid
1.3
0.7
1.6
1.0
1.9
1.3
2.2
1.7
2.5
2.0