Piping Connection; Caution Of Piping - Fujitsu AU G18LVLB Series Design & Technical Manual

2.

PIPING CONNECTION

2-1.

CAUTION OF PIPING

CAUTION
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Keep the permissible length of every piping limitation to prevent a defect or cooling/heating failure.
Piping material
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• Use the designated size ( Diameter & thickness ) of refrigerant pipes.
• Those pipes purchased locally may contain dust inside. Please blow out the dust by dried inert
gas when using.
• To process the branch, do not use T-shaped pipe, which causes a uneven refrigerant flow. Use
the optionally available standard branch kit.
T-tube
• When replacing the unit, never use piping which has been used for previous installations. Only
use the new piping.
Piping process strage
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• Be careful to avoid the dust or water falling into the pipe when performing piping process and
piping installation.
• When processing the pipe, make the number of bending portion as few as possible, and the
bending radius as large as possible.
• If the diameter of the required pipe is different from the branch unit, either cut it out or use the
reducer.
Brazing
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• While Brazing the pipes, be sure to blow dry nitrogen gas through them.
• If nitrogen gas is not blown through the pipes while they are being brazed, an oxidized layer may
form on the inside of the pipes. If this occurs, the cooling efficiency may decrease and the air
conditioner unit (compressor, valves, etc.) cause malfunction.
Rubber stopper
• When brazing the pipes, do not use flux. If the flux is chlorine-based, the pipes will corrode
and when the flux contains fluorine, the refrigerant oil will deteriorate, etc. Using the flux has an
adverse affect on the refrigerant piping system.
• For brazing materials, use phosphor copper solder that does not require flux.
Twin connection type (Gas)
Triple connection type (Gas)
0.02MPa
Pressure hose
Bellows valve
Nitrogen gas
Twin connection type (Liquid)
Triple connection type (Liquid)
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