NOTICE
Contamination of the vacuum chamber from operating fluid backflow
After the vacuum pump is switched off, there is a risk that the connected vacuum system can become
contaminated by backflow.
► Vent the vacuum chamber, regardless of its size, within 30 seconds.
► Shut off the intake line with an additional shut-off valve, after the vacuum pump is switched off
during longer venting operations.
Pfeiffer Vacuum rotary vane pumps have an integral vacuum safety valve on the intake side. The vac-
uum safety valve automatically closes from a differential pressure of
≥250 hPa
between the exhaust
and intake sides, when the vacuum pump is switched off, and vents the vacuum pump.
Procedure
1. If required, switch the vacuum pump off in each pressure range.
2. Switch the mains switch off or securely disconnect the drive motor from the mains.
3. Install an additional shut-off valve in the intake line to ensure that the vacuum is maintained in the
vacuum chamber.
Operation
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