Johnson JR8 Serie Guide D'utilisation page 109

Each branch can only connect to one indoor unit, but
not another branch joint.
× Incorrect
The straight horizontal piping distance between two
adjacent branch pipes should ≥0.5m. The straight
horizontal piping distance which indoor unit
connecting behind the branch pipe should ≥0.5m.
≥500
5.4.6 Brazing
During brazing, use nitrogen as protection to prevent
the formation of a large amount of oxide film in the
pipes. This oxide film will have adverse effects on the
valves and compressors in the cooling system, and
may hamper normal operations.
Use the reducing valve to set the nitrogen pressure
to 0.02~0.03 MPa (a pressure that can be felt by the
skin).
Copper pipe, 1/4"
Brazing part
Nitrogen
Oxygen
Copper Copper pipe Pipe interface
pipe, fittings fittings for
nitrogen filling
Do not use antioxidants when brazing the pipe joints.
Use copper-phosphorus alloys (BCuP) when brazing
copper and copper, and no flux is required. When
brazing copper and other alloy, flux is required.
Flux produces an extremely harmful effect on the
refrigerant piping system. For example, using a
chlorine-based flux is used may corrode the pipes,
and when the flux contains fluorine, it will degrade
the frozen oil.
5.4.7 Connecting stop valves
Stop valves
The following figure shows the names of all parts
required for the installation of the stop valves.
Stop valves are closed when unit is shipped from the
factory.
Fig. 5.31
The pipe orifice of
unused branch
should be sealed.
Fig. 5.32
Packless valve
High pressure
hose for
nitrogen filling
Fig. 5.33
30
Maintenance access and
its valve lid
Stop valve lid
Stop valve connection
tube
e d
a
Sealing component
b
Axis
c
Hexagonal hole
d Stop valve lid
a
Maintenance access
b e
c
Using of stop valve
1. Remove the stop valve lid.
2. Insert the hex wrench into the stop valve, and rotate
the stop valve counter-clockwise.
3. Stop turning when the stop valve cannot be rotated
further.
Result: Valve is now open.
The fastening torque of the stop value is shown in table
5.5. Insufficient torque may cause the refrigerant to leak.
2
3
1
4
Closing the stop valve
1. Remove the stop valve lid.
2. Insert the hex wrench into the stop valve, and rotate
the stop valve clockwise.
3. Stop turning when the stop valve cannot be rotated
further.
Result: Valve is now closed.
Direction to close:
Fig. 5.34
Fig. 5.35
Fig. 5.36
Fig. 5.37
V.1