N
2
Schrader
24
INSTALLATION AND SERVICE
System pressure test
Always use an inert gas such as nitro-
gen for the pressure test. Never use
other gasses such as oxygen, dry air
or acetylene. These gasses may form
an infl ammable mixture with the com-
pressor oil. Always use the appropriate
pressure regulator with gas cylinders.
Any attempt to use a high pressure
gas supply without a suitable pressure
regulator can lead to personal injury
or death as well as system damage.
The maximum allowed test pressures
for NTZ compressors are:
Maximum compressor test pressure at low pressure side
(suction side)
25 bar (g)
Maximum compressor test pressure at high pressure side
(discharge side)
30 bar (g)
Maximum test pressure diff erence between high and low pressure
side (to avoid that the internal compressor relief valve will open)
30 bar
Compressor connection
to the system
New compressors have a protective
nitrogen holding charge. Only remove
the suction and discharge plugs just
before connecting the compressor to
the installation, so as to prevent air
and moisture from entering the com-
pressor. Remove the discharge plug
fi rst and the suction plug next; by pro-
ceeding as such, the nitrogen holding
charge can escape via the discharge
connection and the risk of an oil mist
blow-out via the suction connection
will be minimal.
Whenever possible the compressor
must be the last component to be
integrated in the system. It is advis-
able to braze the solder sleeves or
service valves to the pipework before
the compressor is mounted. when all
brazing is fi nished and when the total
system is ready, the compressor plugs
can be removed and the compressor
can be mounted to the system with
a minimum exposure to ambient air.
If this procedure is not possible, the
sleeves or valves may be brazed to the
pipes when mounted on the compres-
sor. In this situation nitrogen or CO
2
must be purged through the compres-
sor via the schrader valve to prevent
air and moisture ingress. Purging must
start when the plugs are removed and
maintained during the brazing proc-
ess.
When rotolock valves are used on the
compressor, they shall be closed im-
mediately after mounting, thus keep-
ing the compressor isolated from
atmosphere or from a not yet dehy-
drated system.
Note:
when the compressor is built
into a «pack» or «rack» confi guration
which is not installed immediately on
its fi nal location, a vacuum pull-down
and moisture removal must be per-
formed to the "pack" or "rack" as if it
were a complete system (see below).
the pack must be charged with nitro-
gen or CO
2
and open tubes must be
blocked with caps or plugs.
