Hitachi FSXN Series Service Manual page 60

3 Piping work and
refrigerant charge
P. Refrigerant gas/liquid pressure.
C A U T I O N
• Do not force the valve open buffer; this could damage the seat of the valve. A spare valve seat is not supplied.
• When performing the start-up test, open valve to the full. Otherwise, the system may be damaged.
¿ Refrigerant pipe connection
R A S -8FS X N R A S -10FS X N
A
A
J
J
B
C
K
D
I
E
H
G
G
F
H
A. Stop valve (gas, high pressure).
B. Stop valve (liquid).
C. Flared connection.
D. Liquid pipe (field-supplied).
E. Pipe accessory.
F. Gas pipe, high pressure (field-supplied).
D A N G E R
• Check that the gas and liquid stop valves are fully closed.
• Check that there is no gas inside the pipe before removing the stop pipe. Otherwise, the pipe may explode
when heated with the blow torch.
Special care should be taken to ensure that the flame from the blow torch does not fall on the body of the stop valve, on
the compressor and cover or on the insulation bushings; insert a metal plate in front of the oil return pipe:
valve, see on page 43.
Connect the indoor units to the outdoor units using copper pipes specifically for use with refrigerant. When laying the pipes
make sure that they do not directly rest on or touch walls or other parts of the building (when the refrigerant is flowing
through the pipes, this could cause strange noises).
Specific torques for the flared connections:
While welding, apply a flow of nitrogen gas inside the pipe.
Fully insulate the refrigerant pipes.
C A U T I O N
Fit the pipe protection provided with the outdoor unit on completion of the installation work. Otherwise, the unit
may be damaged by the entrance of snow, water or rodents.
53
SMGB0065 rev. 1 - 12/2010
R A S -12FS X N
A
B
J
B
C
C
D
L
I
E
K
H
D
F
F
G
Flared connection
R A S -14FS X N
R A S -16FS X N
A
J
B
C
D
K
E
G
H
F
G. Gas pipe, low pressure (field-supplied).
H. L-bend (field-supplied)
I. Pipe accessory.
J. Stop valve (gas, low pressure).
K. Pipe accessory.
L. Pipe accessory.
mounting, see on page 40.
R A S -18FS X N
A
J
B
C
3
L
I
E
H
D
G
F
Gas stop