Fujitsu AIRSTAGE J-IIIL, Design & Technical Manual

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3. Piping connection
Keep the permissible length of every piping limitation to prevent a defect or cooling/heating failure.
CAUTION
• Piping material:
– Use the designated size (diameter and thickness) of refrigerant pipes.
– Those pipes purchased locally may contain dust inside. Use dry nitrogen to blow out any dust.
– Do not use standard pipe tees for branches, these can cause uneven refrigerant flow to the
indoor units. Optionally available standard branch kits should be used instead.
T-tube Separation tube Reducer
Prohibited OK
– When replacing the unit, never use piping which has been used for previous installations. On-
ly use the new piping.
• Piping preparation and installation:
– Make sure that no dust or water enters the pipe during preparation or installation.
– When installing the pipe, make bends as few as possible, and make radius as large as possi-
ble.
– Cut the branch kit at the right size or use the reducer to match the pipe to the branch kit.
• Piping treatment:
– The pipes vibrate, expand, and contract during operation, so if loads are concentrated in one
area, it could cause cracks in the pipes. Provide the pipe supports every 6 to 9 ft (2 to 3 m).
– Make sure to insulate the refrigeration pipes separately with appropriately sized insulation as
described earlier. Make sure to overlap the ends to prevent any gap.
• Brazing:
– While brazing the pipes, be sure to blow dry nitrogen gas through them.
0.02 MPa
Pressure hose
Belows valve
Nitrogen gas
Rubber stopper
(continued)
- (06-35) -
3. Piping connection
SYSTEM DESIGN SYSTEM DESIGN