Pipe Bending Guidelines; To Flare The Pipe End; To Braze The Pipe End; Using The Stop Valve And Service Port - Daikin RXYSQ6T7Y1B9 Installer's Manual

Piping size Tightening
(mm) torque (N•m)
Ø6.4 15~17
Ø9.5 33~39
Ø12.7 50~60
Ø15.9 63~75
Ø19.1 90~110
6.4.4

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).
6.4.5

To flare the pipe end

CAUTION
▪ Incomplete flaring may cause refrigerant gas leakage.
▪ Do NOT re-use flares. Use new flares to prevent
refrigerant gas leakage.
▪ Use flare nuts that are included with the unit. Using
different flare nuts may cause refrigerant gas leakage.
1 Cut the pipe end with a pipe cutter.
2 Remove burrs with the cut surface facing downward so that the
chips do not enter the pipe.
a b
a Cut exactly at right angles.
b Remove burrs.
3 Remove the flare nut from the stop valve and put the flare nut
on the pipe.
4 Flare the pipe. Set exactly at the position as shown in the
following illustration.
A
Flare tool for Clutch type
R410A (clutch
(Ridgid-type)
type)
A 0~0.5 mm 1.0~1.5 mm
5 Check that the flaring is properly made.
a b
c
a Flare's inner surface must be flawless.
b The pipe end must be evenly flared in a perfect circle.
c Make sure the flare nut is fitted.
RXYSQ6T7Y1B9
VRV IV-S system air conditioner
4P404677-1A – 2016.03
Flare Flare shape
dimensions (A) (mm)
(mm)
90° ±2
8.7~9.1
A
12.8~13.2
16.2~16.6
R=0.4~0.8
19.3~19.7
23.6~24.0
Conventional flare tool
Wing nut type
(Imperial-type)
1.5~2.0 mm
6.4.6

To braze the pipe end

NOTICE
Precautions when connecting field piping. Add brazing
material as shown in the figure.
≤Ø25.4
1
1
▪ 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 (just enough so it can be felt
on the skin) with a pressure-reducing valve.
a b
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.
6.4.7

Using the stop valve and service port

To handle the stop valve
▪ Make sure to keep all stop valves open during operation.
▪ The figure below shows the name of each part required in
handling the stop valve.
▪ The stop valve is factory closed.
a
b
c
d
a Service port and service port cover
b Stop valve
c Field piping connection
d Stop valve cover
a b
e d c
6 Installation
c d e
f
Installer and user reference guide
17