Daikin VRV 5-S Series - 18.2.4 Brazing Pipe Ends

18 | Piping installation
Installer and user reference guide
82
RXYSA4~6A7V/Y1B
VRV 5-S system air conditioner
4P600330-1 – 2020.01
Unit Installation period Protection method
Outdoor unit >1month Pinch the pipe
<1month Pinch or tape the pipe
Indoor unit Regardless of the period
INFORMATION
Do NOT open the refrigerant stop valve before checking the refrigerant piping. When
you need to charge additional refrigerant it is recommended to open the refrigerant
stop valve after charging.
18.2.3 Pipe bending guidelines
Use a pipe bender for bending. All pipe bends should be as gentle as possible
(bending radius should be 30~40 mm or larger).
18.2.4 To braze the pipe end
NOTICE
Precautions when connecting field piping. Add brazing material as shown in the
figure.
1
1
≤Ø25.4
▪ When brazing, blow through with nitrogen to prevent creation of large quantities
of oxidised film on the inside of the piping. This film adversely affects valves and
compressors in the refrigerating system and prevents proper operation.
▪ Set the nitrogen pressure to 20kPa (0.2bar) (just enough so it can be felt on the
skin) with a pressure-reducing valve.
a b c d e
f
f
a Refrigerant piping
b Part to be brazed
c Taping
d Manual valve
e Pressure-reducing valve
f Nitrogen
▪ Do NOT use anti-oxidants when brazing pipe joints.
Residue can clog pipes and break equipment.
▪ Do NOT use flux when brazing copper-to-copper refrigerant piping. Use phosphor
copper brazing filler alloy (BCuP), which does not require flux.
Flux has an extremely harmful influence on refrigerant piping systems. For
instance, if chlorine based flux is used, it will cause pipe corrosion or, in
particular, if the flux contains fluorine, it will deteriorate the refrigerant oil.
▪ Always protect the surrounding surfaces (e.g. insulation foam) from heat when
brazing.