Daikin ERLA03DAV3, Руководство по установке для специалистов, Страница: 62 / 192

7 | Piping installation
Installer reference guide
62
ERLA EHFZ03S18DJ3V
Daikin Altherma 3 R F
4P596821-1A – 2020.05
7.3.6 To braze the pipe end
The indoor unit and outdoor unit have flare connections. Connect both ends
without brazing. If brazing should be needed, take the following into account:
▪ 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.
7.3.7 Using the stop valve and service port
CAUTION
Do NOT open the valves before flaring is complete. This would cause refrigerant gas
leakage.
To handle the stop valve
Take the following guidelines into account:
▪ The stop valves are factory closed.
▪ The following figure shows the stop valve parts required when handling the
valve.
c
d
a
b
a Service port and service port cap
b Valve stem
c Field piping connection
d Stem cap
▪ Keep both stop valves open during operation.
▪ Do NOT apply excessive force to the valve stem. Doing so may break the valve
body.