Daikin VRV FXZQ07MVJU9, Installation Manual

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12 3P184443-12N English
Not recommended but in case of emergency:
You must use a torque wrench but if one is not available, you may follow the installation method
described below.
When you keep 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 at the angle shown below:
Pipe size Further tightening angle Recommended arm length of tool
ø1/4” 60 – 90 degrees Approx. 6 in.
ø1/2” 30 – 60 degrees Approx. 10 in.
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
(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 field refrigerant piping, nitrogen gas shall be blown through the piping to expel air from
the piping.
If 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 connection.
• Nitrogen should be set to 2.9 psig with a pressure-reducing valve if brazing while inserting nitrogen into
the piping.
(Refer to Fig.15)
Refrigerant piping
Part to be
brazed
Taping
Nitrogen
Pressure-reducing valve
Nitrogen
Hand valve
Fig. 15
• Make absolutely sure to execute thermal insulation works on the pipe-connecting section after
checking gas leakage by thoroughly studying the following figure and using the attached insulation for
fitting (8) and (9). Fasten both ends with the clamps (4).
(Refer to Fig. 16)
• Wrap the sealing pad (11) only around the insulation for the joints on the gas piping side.
(Refer to Fig. 16)