Pipe Connection; Insulation Of Multikits And/Or Branches - Hitachi RCI Service Manual

3 Piping work and
refrigerant charge

3.2.2 Pipe connection

End of refrigerant pipe protected correctly.
Cover the end of the pipe appropriately when it is to be inserted
through holes in walls and roofs, etc.
Keep the ends of the pipes covered while other installation work is
being carried out to avoid the entry of dampness or dirt.
End of refrigerant pipe unprotected.
Do not place the pipes directly on the ground without appropriate
protection or adhesive vinyl tape to cover the ends.
Where the pipe installation is not completed for a certain amount
of time, weld the ends of the pipe to seal. Then fill it with oxygen-
free nitrogen gas through a Schrader valve to avoid the
accumulation of humidity and/or contamination through dirt.
Secure the connection pipe as indicated in the image. Use the
indoor unit's insulation.
A: flare nut on the indoor unit.
B: insulation on the pipe connection to the indoor unit using the
insulating material supplied.
C: secure the insulation using the flange supplied or using suitable
adhesive tape.
D: Installation refrigerant gas pipe.
E: installation insulation (field-supplied).
F: brazing.
G: flare the pipe after inserting the flare nut.
H: indoor unit insulation.
I: indoor unit.
N O T E
• Where polyethylene foam insulation is used, a 10 mm thick layer should be used for the liquid pipe and between
15 and 20 mm for the gas pipe.
• Install the insulation after the pipe surface temperature has dropped to the room temperature, otherwise the
insulation may melt.
Do not use insulating material that contains NH
cause leaks.
Where the fitter has supplied his own branches, these should be appropriately insulated to avoid decreases in capacity in
line with to environmental conditions and condensation on the surface of the piping due to low pressure.

3.2.3 Insulation of multikits and/or branches

Install the insulation packages in the multikits and/or branches using suitable vinyl tape.
80
SMGB0063 rev. 1 - 10/2010
(ammonium), as it could damage the copper in the pipe and subsequently
3