Hitachi RAI-50RPA RAI50RPA User Manual
Product codes
RAI50RPA
11-2
11.1. REFRIGERANT PIPING
11.1.1. PREPARATION OF PIPE
•
•
Use a pipe cutter to cut the copper pipe
CAUTION
•
•
Jagged edge will cause leakage
•
Point the side to be trimmed downwards during
trimming to prevent copper chips from entering the
pipe
trimming to prevent copper chips from entering the
pipe
•
Before flaring, please put on the flare nut and use
exclusive tool
exclusive tool
Outer diameter
(Ø)
A (mm)
Imperial flaring tool
Rigid flaring tool
6.35mm (1/4”)
0~0.5 mm
1.0 mm
9.52mm (3/8”)
0~0.5 mm
1.0 mm
12.7mm (1/2”)
0~0.5 mm
1.0 mm
15.88mm (5/8”)
0~0.5 mm
1.0 mm
11.1.2. PIPE CONNECTION
Caution
•
•
In case of removing flare nut of an indoor unit, first
remove a nut of small diameter side, or else a seal cap
of big diameter side will fly out. Prevent water from
entering into piping when working
remove a nut of small diameter side, or else a seal cap
of big diameter side will fly out. Prevent water from
entering into piping when working
•
Please be careful when bending the copper pipe.
•
Screw in manually while adjusting the center. After
that, use a torque wrench to tighten the connection.
that, use a torque wrench to tighten the connection.
Outer dia of pipe Torque N.m (kgf.cm)
Small dia side
6.35mm (1/4”) 13.7~18.6 (140~190)
Large dia side
9.52mm (3/8”) 34.3~44.1 (350~450)
12.7mm (1/2”) 44.1~53.9 (450~550)
12.7mm (1/2”) 44.1~53.9 (450~550)
15.88mm (5/8”) 49.0~58.8 (500~600)
Valve
head
cap
Small dia side 6.35mm (1/4”) 19.6~24.5 (200~250)
Large dia side
9.52mm (3/8”) 19.6~24.5 (200~250)
12.7mm (1/2”) 29.4~34.3 (300~350)
12.7mm (1/2”) 29.4~34.3 (300~350)
15.88mm (5/8”) 29.4~34.3 (300~350)
Valve core cap
12.3~15.7 (125~160)
11.1.3. REMOVAL OF AIR FROM THE PIPE AND GAS
LEAKAGE INSPECTION
Procedures of using Vacuum Pump for Air
Removal
Removal
①As shown in figure below , remove the cap of valve core.
Then, connect the charge hose. Remove the cap of
valve head. Connect the vacuum pump adaptor to the
vacuum pump and connect to
valve head. Connect the vacuum pump adaptor to the
vacuum pump and connect to
②Fully tighten the “Hi” shuttle of the manifold valve and
completely unscrew the “Lo” shuttle. Run the vacuum
pump for about 10~15 minutes, then completely tighten
the “Lo” shuttle and switch off the vacuum pump
pump for about 10~15 minutes, then completely tighten
the “Lo” shuttle and switch off the vacuum pump
③Completely unscrew the spindle of the service valve (at 2
places) in anticlockwise direction to allow the flow of
coolant (using Hexagonal Wrench key).
coolant (using Hexagonal Wrench key).
④Remove the charge hose and tighten the cap of valve
head. Check the cap’s periphery if there is any gas
leakage. The task is then completed.
leakage. The task is then completed.
Copper pipe
Trimming tool
Die
Die
Copper pipe
Wrench
Flare nut
Torque
wrench
wrench
Meter showing pressure
Closed
Manifold valve
Valve
Vacuum
pump
pump
Vacuum pump
adaptor
adaptor
Valve
Charge hose
When the meter reaches -101kPa (-76cmHg)
during pumping, fully tighten the shuttle
during pumping, fully tighten the shuttle
The body of
service valve
service valve
Cap of valve
core
core
Hexagonal
Wrench key
Wrench key
Cap of valve head
Cap of valve head
When pumping starts, slightly loosen the
flare nut to check of air sucked in. Then
tighten the flare nut.
flare nut to check of air sucked in. Then
tighten the flare nut.