Hitachi YUTAKI S Serie Manual De Instalación Y Funcionamiento página 24

10.1. REFRIGERANT PIPING WORK
10.1.1. PIPING MATERIALS
1. Prepare locally-supplied copper pipes.
2. Select the piping size with the correct thickness and correct
material which can have sufficient pressure strength.
3. Select clean copper pipes. Make sure there is no dust and
moisture inside. Blow the inside of the pipes with oxygen
free nitrogen to remove any dust and foreign materials
before connecting pipes.
4. After connecting the refrigerant piping, seal the open
space between Knockout hole and refrigerant pipes by
using insulation material as shown bellow:
Unit Side
Insulation material

NOTE:
A system with no moisture or oil contamination will give
maximum performance and lifecycle compared to that of a
poorly prepared system. Take particular care to ensure all
copper piping is clean and dry internally.
There is no refrigerant in the cycle of the indoor unit.
10.1.2. SUSPENSION OF REFRIGERANT PIPING
Suspend the refrigerant piping at certain points and prevent the
refrigerant piping from touching the weak part of the building
such as wall, ceiling, etc.
(If touched, abnormal sound may occur due to the vibration of
the piping. Pay special attention in case of short piping length).
1 ~ 15m
26
PMML0215A rev.1 - 02/2012
Insulation material
Field-Supplied
Insulation material
Fire-Proof
Section
Treatment
Indoor Unit

CAUTION:
Cap the end of the pipe when pipe is to be inserted
through a hole.
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.
Do not use insulation material that contains NH3 because
it can damage cooper pipe material and can be a source of
future leakage.
Completely insulate both refrigerant gas piping and liquid
piping between the indoor unit(s) and the outdoor unit.
If not insulated, dew will ocur on the piping surface.
Do not fix the refrigerant piping directly with the metal fittings
(The refrigerant piping may expand and contract).
Some examples for suspension method are shown below.
For Suspending
Heavies Along The Wall
PIPING AND
REFRIGERANT CHARGE
For Piping For Instant
Installation Work