Flaring guidelines
Flares should not be re-used. New ones should be made in
order to prevent leaks.
Use a pipe cutter and flare tool suitable for the refrigerant used.
Only use the flare nuts included with the unit. Using different
flare nuts may cause the refrigerant to leak.
Please refer to the table for flaring dimensions and tightening
torques (too much tightening will result in splitting the flare).
Piping size
Tightening
(mm)
torque (N•m)
Ø9.5
33~39
Ø15.9
63~75
When connecting the flare nut, coat the flare inner surface with
ether oil or with ester oil and initially tighten 3 or 4 turns by hand
before tightening firmly.
When loosening a flare nut, always use two wrenches together.
When connecting the piping, always use a spanner and torque
wrench together to tighten the flare nut to prevent flare nut
cracking and leaks.
1
4
3
Not recommended, but in case of emergency
Should you be forced to connect the piping without a torque
wrench, follow the following installation method:
Tighten the flare nut using a spanner until the tightening
torque suddenly increases.
From that position further tighten the flare nut the angle listed
below:
Piping size
Further tightening angle
(mm)
(degrees)
Ø9.5
60~90
Ø15.9
30~60
RRHQ0011~016AAV3(8) + RRHQ011~016AAW18
Outdoor unit for air to water heat pump
4PW50202-1
Flare dimensions A
Flare shape
(mm)
(mm)
90 ±2
12.8~13.2
A
R=0.4~0.8
19.4~19.7
1
Torque wrench
2
Spanner
3
Piping union
2
4
Flare nut
Recommended arm
length of spanner (mm)
±200
±300
Brazing guidelines
Make sure to blow through with nitrogen when brazing.
Blowing through with nitrogen prevents the creation of large
quantities of oxidized film on the inside of the piping. An oxidized
film adversely affects valves and compressors in the
refrigerating system and prevents proper operation.
The nitrogen pressure should be set to 0.02 MPa (i.e., just
enough so it can be felt on the skin) with a pressure-reducing
valve.
1
2
6
1
Refrigerant piping
2
Part to be brazed
3
Taping
4
Manual valve
5
Pressure-reducing valve
6
Nitrogen
Do not use anti-oxidants when brazing the 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.
Stop valve operation
Cautions on handling the stop valve
Make sure to keep both stop valves open during operation.
The figure below shows the name of each part required in
handling the stop valve.
1
1
2
3
2
4
3
4
The stop valve is factory closed.
Do not apply excessive force to the valve stem. Doing so may
break the valve body.
Since the stop valve mounting plate may be deformed if only a
torque wrench is used to loosen or tighten the flare nut, always
make sure to secure the stop valve with a spanner, then loosen
or tighten the flare nut with a torque wrench.
Do not place the spanner on the stem cap, as this could cause a
refrigerant leak.
3
4
5
6
Service port and service port cap
Valve stem
Field piping connection
Stem cap
1 Spanner
2 Torque wrench
1
2
Installation manual
6