6 Installation
Installer and user reference guide
21
RXYTQ8~16U7YF
VRV IV+ heat pump for high ambient temperatures
4P561157-1 – 2018.09
a
a
Close the areas marked with "
". (When the piping is
routed from the front panel.)
▪ Only use clean pipes.
▪ Hold the pipe end downwards when removing burrs.
▪ Cover the pipe end when inserting it through a wall, to prevent
dust and/or particles entering the pipe.
6.4.9
To braze the pipe end
NOTICE
Precautions when connecting field piping. Add brazing
material as shown in the figure.
1
1
1
1
2
2
≤Ø25.4
>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.
6.4.10
Using the stop valve and service port
To handle the stop valve
▪ Make sure to keep all stop valves open during operation.
▪ The gas and liquid stop valves are factory closed.
▪ The figures below show the name of each part required in
handling the stop valve.
c
d
a
b
a
Service port and service port cover
b
Stop valve
c
Field piping connection
d
Dust cap
a
b
c
d
e
a
Service port
b
Dust cap
c
Hexagon hole
d
Shaft
e
Seal
To open/close the stop valve
1
Remove the dust cap.
2
Insert a hexagon wrench (liquid side: 4 mm, gas side: 8 mm)
into the stop valve and turn the stop valve:
Counterclockwise to open.
Clockwise to close.
3
Tighten the stop valve securely when opening or closing the
stop valve. For the correct tightening torque value, refer to the
table below.
NOTICE
Inadequate torque may cause leakage of refrigerant and
breakage of the stop valve.
4
Install the dust cap.
Result:
The valve is now open/closed.
To handle the service port
▪ Always use a charge hose equipped with a valve depressor pin,
since the service port is a Schrader type valve.
▪ After handling the service port, make sure to tighten the service
port cover securely. For the tightening torque, refer to the table
below.
▪ Check for refrigerant leaks after tightening the service port cover.
Tightening torques
Stop valve
size (mm)
Tightening torque (when opening or closing)
Valve body
Hexagonal
wrench
Service port
Ø9.5
5~7 N•m
4 mm
10.7~14.7
Ø12.7
8~10 N•m
Ø15.9
14~16 N•m
6 mm
Ø19.1
19~21 N•m
8 mm
Ø25.4
