15
Operation
6
Operation
6.1 Before switching on the pump
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Check the operating fluid level in the sightglass.
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Compare the voltage and frequency information on the rating plate with the
mains voltage and frequency values.
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Check that the exhaust connection allows free flow (max. permissible pressure
1.5 bar absolute).
– Activate the shut-off valves in such a way that they open before or at the same
time as the pump is started.
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Protect the pump sufficiently from taking in contaminants by means of suitable
precautions (e.g. dust filters); if necessary, check operating fluid regularly or re-
place at shorter intervals.
6.2 Switching on the pump
The pump can be switched on in any pressure range.
No special precautions are necessary when pumping dry gases. In order to attain
the lowest possible final pressures, the gas ballast valve should be closed.
6.3 Pumping condensable vapours
Should the process gases contain condensable gases present at high percentages,
the rotary vane pump must be operated with a gas ballast (i.e. with an open gas
ballast valve).
No special precautions are necessary when pumping dry gases, provided that the
correct pump version is used with the operating fluid specified for it.
Gas ballast valve,
standard version
To avoid condensation in the pump when pumping condensable vapours, ambient
air or alternatively inertgas is periodically fed into the working chamber at the be-
ginning of the compression phase via the gas ballast valve 74.
The gas ballast valve is closed when turning to the right to position 0 and open
when turning to the left to position 1. Intermediate settings are not possible.
CAUTION
Hot surface!
Danger of burns if hot parts are touched. Depending on the operating and ambient
conditions, the surface temperature of the pump may rise above 70 °C.
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In this case, use suitable finger guards.
CAUTION
Bad final vacuum and damage to the pump!
Danger of condensation and corrosion due to exceeding the water vapour compatibi-
lity (see Technical data) during operation without a gas ballast or in case of insufficient
supply of flushing gas.
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Only pump vapours when the pump is warm and the gas ballast valve is open.
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When the process has been completed, allow the pump to continue running for
about 30 minutes with the vacuum flange closed and the gas ballast open for ope-
rating fluid regeneration purposes.
