Daikin FXAQ20PVE Installation Manual page 12

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
follow 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
suddenly increases. From that position, further tighten the flare nut the angle shown below:
Table 2
Pipe size
φ 6.4 (1/4")
φ 9.5 (3/8")
φ12.7 (1/2")
φ15.9 (5/8")
After the work is finished, make sure to check that there is no gas leak.
CAUTION
CAUTION TO BE TAKEN WHEN BRAZING REFRIGERANT PIPING
"Do not use flux when brazing refrigerant piping. Therefore, use the phosphor copper brazing filler metal
(BCuP-2: JIS Z 3264/B-Cu93P-710/795: ISO 3677) which does not require flux."
(Flux has extremely harmful influence on refrigerant piping systems. 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 piping,
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 with a pressure-reducing valve if brazing while inserting nitrogen into
the piping. (Refer to Fig.14)
Refrigerant piping
CAUTION
Be sure to insulate any field piping all the way to the piping connection inside the unit. Any exposed piping
may cause condensation or burns if touched.
English
Further tightening angle
60 - 90 degrees
60 - 90 degrees
30 - 60 degrees
30 - 60 degrees
Part to be
brazed
Nitrogen
Recommended arm length of tool
Pressure-reducing valve
Taping
hands valve
Approx. 150mm
Approx. 200mm
Approx. 250mm
Approx. 300mm
Nitrogen Fig. 14
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