Hitachi UTOPIA R32 Series Installation And Operation Manual page 27

• Use nitrogen gas for blowing during pipe brazing work. Otherwise a lot of oxidation film will
occur inside of tubes. This film will be flecked off after operation and will circulate in the cycle,
resulting in clogged expansion valves, bad influence to the compressor, etc.
• Cap the end of the pipe when pipe is to be inserted through a hole or while other installation
work is being carried out, do not put pipes on the ground directly without a cap or vinyl tape at
the end of the pipe.
• If piping installation is not completed until next day or over a longer period of time, braze off the
ends of the piping and charge with oxygen free nitrogen through a Schrader valve type access
fitting to prevent moisture and particle contamination.
In case of getting the pipe through a hole in the wall:
Do not place the pipe directly on the ground:
In case of rain:
Where the copper pipe is supplied in rolls, fit a cap on the end and unwind it while it is resting on
the ground so that the turning movement of the roll as it is unwound forms a straight pipe.

NOTE
• The rolls of copper refrigeration pipe are normally supplied with caps on their ends.
• Where the roll of pipe does not come supplied with caps, check that the inside of the pipe is
clean. If it is not, use a new roll of pipe.
• It is also possible to cover the end of the pipe temporarily using high quality adhesive tape.
• Do not wind and unwind the pipe continuously, as the properties of the copper for refrigeration
pipes are altered, making it more rigid and brittle.
PMEN0654 rev.0 - 12/2023
In Case of Getting the Pipe
Through a Hole in the Wall
Incorrect
Correct
Hole Hole
Attach a cap or put a plastic bag
over the pipe end.
In Case of Rain
Correct Incorrect
Rain water
can come in.
Rubber Band
Attach a cap or put a plastic
bag over the pipe end.
In Case of Getting the Pipe
Through a Hole in the Wall
Correct
In Case of Getting the Pipe
Correct
Through a Hole in the Wall
Hole
Hole Hole
Hole
Correct
Do not place the pipe
directly on the ground.
Cap or plastic bag
Attach a cap or put a plastic bag
Hole Hole
Correct
over the pipe end.
Correct
In Case of Rain
Attach a cap or put a plastic bag
Correct
over the pipe end.
In Case of Rain
Rain water
Cap or plastic bag
Attach a cap or put a plastic
can come in.
Correct
bag over the pipe end.
Correct
Rain water can Rain water
Rubber Band
can come in.
come in
Attach a cap or put a plastic
bag over the pipe end.
Rubber band Rubber Band
Cap or plastic bag
Attach a cap or put a plastic
bag over the pipe end.
Incorrect Correct
Incorrect
Incorrect Correct
Attach a cap
Incorrect
bag over the
Incorrect
Attach a cap
Incorrect
bag over the
Incorrect
Incorrect
18
Do not pla
directly on
Do not pla
directly on
5