Refrigerant Piping Connection; Vacuum Pumping - Toshiba RAS-10SA-E-1 Service Manual

8-5-1. Refrigerant Piping Connection

<Flaring>
(1) Cut the pipe with a pipe cutter.
90˚
Fig. 8-5-2
(2) Insert a flare nut into the pipe, and flare the pipe.
A
Die Pipe
Fig. 8-5-3
<Tightening connection>
Align the centers of the connecting pipes and tighten
the flare nut as far as possible with your fingers. Then
tighten the nut with a spanner and torque wrench as
shown in the figure.
CAUTION
• Do not apply excess torque. Otherwise, the
nut may crack depending on the installation
conditions.
Outer diam. Tightening torque
6.35 mm 15.7 (1.6 kgf·m)
9.52 mm 29.4 (3.0 kgf
Half union or packed valve
Externally
threaded
side
Use a wrench
to secure.
Fig. 8-5-4
Obliquity Roughness Warp
A (mm)
Outer
diam.
Imperial Rigid
6.35 mm
1.3 mm 0.7 mm
9.52 mm 1.6 mm 1.0 mm
(Unit : N·m)
Additional
tightening torque
19.6 (2.0 kgf·m)
· 34.3 (3.5 kgf·m)
m)
Flare nut
Internally
threaded
side
Use a torque wrench
to tighten.

8-5-2. Vacuum Pumping

AIR PURGE
Evacuate the air in the connecting pipes and in
the indoor unit using vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the manual of vacuum pump.
<Use of vacuum pump>
(1) Connect the charge hose (A) from the manifold
valve to the charge inlet of the gas side packed
valve.
(2) Connect the charge hose (B) to the port of vacuum
pump.
(3) Open fully the low pressure side handle of the
manifold valve.
(4) Operate the vacuum pump.
(5) Close the low pressure side handle of manifold
valve after vacuumizing and stop the vacuum
pump.
Continue vacuumizing more than 15 minutes and
check the pressure gauge indicates –76 cmHg
(–1.013×10 5 Pa).
(6) Open the stems of packed valves A and B all the
way.
(7) Securely tighten the stem cap to each of the
packed valve stems.
Low pressure side handle
Indoor unit
Gas
(ø9.52)
C
D
Liquid
(ø6.35)
– 29 –
Manifold valve
Pressure gage
Charge hose (A)
Lo
Outdoor unit
Service port
A
Packed
B
valve
Fig. 8-5-5
High pressure
side handle
Hi
Charge
hose (B)
VP