The vacuum pump achieves the specified throughput and ultimate pressure values once the operating
temperature has been reached.
6.3 Operating the vacuum pump with gas ballast
NOTICE
Risk of damage from condensation in vacuum pump
During operation without gas ballast, condensation may form as a result of the vapor compatibility of
the vacuum pump being exceeded.
► Pump condensable vapors only when the vacuum pump is warm and the gas ballast valve open.
► Allow the vacuum pump to run on after process end for another 30 minutes with the gas ballast
valve open.
– This protects the vacuum pump against corrosion.
No intermediate settings possible
An intermediate setting between open and closed is not possible.
The gas ballast valve supplies air to the working chamber of the vacuum pump periodically at the begin-
ning of the compression phase. When pumping down vapors, this air prevents condensation within cer-
tain limits in the vacuum pump.
1
"I"
"0"
Fig. 4:
Gas ballast valve
1
Sleeve on the gas ballast valve
Position "I"
Gas ballast valve open
Position "0" Gas ballast valve closed
Behavior with process gases with condensable vapors
► Operate the vacuum pump with gas ballast, i.e. with the gas ballast valve open.
Open gas ballast valve
► To open the gas ballast valve, push the sleeve on the valve down into position “
I
”.
Close gas ballast valve
► To close the gas ballast valve, push the sleeve on the valve upwards into position “
0
”.
6.4 Switching off the vacuum pump
Procedure
1. Allow the vacuum pump to run on for 5 to 10 minutes with the vacuum connection open to allow
any condensate that may be present to be removed from the vacuum pump.
2. If required, switch the vacuum pump off in each pressure range at the mains switch.
Operation
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