Daikin VRV III Manual page 447

Installation
CAUTION
Be sure to insulate any field pipe all the way to the pipe connection inside the unit. Any exposed pipe may cause
condensate or burns if touched.
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 unit with a flared or a flanged
connection.
Nitrogen should be set to 0.02 MPa (0.2 kg/cm
into the piping.
442
2
Refr igerant
piping
Part to be
brazed
Nitrogen
Fig. 11
) with a pressure-reducing valve if brazing while inserting nitrogen
Pressure-reducing valve
Taping
hands
valve
Nitrogen
: http://splitoff.ru/tehn-doc.html
ED34-862
FXMQ-MF