10
English
Not recommendable but in case of emergency
You must use a torque wrench but if you are obliged to install the unit without a torque wrench, you may fol-
low the installation method mentioned below.
After the work is finished, make sure to check that there is no gas leak.
When you keep on tightening the flare nut with a spanner, there is a point where the tightening torque sud-
denly increases. From that position, further tighten the flare nut the angle shown below:
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING
“
Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazing filter metal
(BCuP) which does not require flux.
”
(Flux has extremely harmful infulence on refrigerant piping sysems. For instance, if the chlorine based
flux is used, it will cause pipe corrosion or, in particular, if the flux contains fluorine, it will damage the
refrigerant oil.)
• Before brazing local refrigerant piping, nitrogen gas shall be blown through the piping to expel air from the
piping.
If your brazing is done without nitrogen gas blowing, a large amount of oxide film develops inside the pip-
ing, and could cause system malfunction.
• When brazing the refrigerant piping, only begin brazing after having carried out nitrogen substitution or
while inserting nitrogen into the refrigerant piping. Once this is done, connect the indoor unit with a flared
or a flanged connection.
• Nitrogen should be set to 0.02 Mpa (0.2 kg/cm
2
) with a pressure-reducing valve if brazing while inserting
nitrogen into the piping.
(Refer to Fig.15)
Pipe size
Further tightening angle
Recommended arm length of tool
ø6.4 (1/4")
60 to 90 degrees
Approx. 150mm
ø9.5 (3/8")
60 to 90 degrees
Approx. 200mm
ø12.7 (1/2")
30 to 60 degrees
Approx. 250mm
Nitrogen
Pressure-reducing valve
hands valve
Taping
Refrigerant piping
Part to be
brazed
Nitrogen
Fig. 15
