max.
min.
1
2
Fig. 22:
Fill pump with operating fluid
1
Filler screw
2
O-ring
Refilling operating fluid
1. Unscrew the operating fluid filler screw.
2. Refill operating fluid up to the “max.” marking, with the pump at operating temperature.
3. Screw in the operating fluid filler screw.
– Be careful with the O-ring.
6.6 Switching off the pump
You can switch off the pump in each pressure range.
Pfeiffer Vacuum rotary vane pumps have an integrated safety valve on the intake side. The safety valve
automatically closes from a differential pressure of
≥250 hPa
between the exhaust and intake sides,
when the pump is switched on, and vents the pump.
6.6.1 Venting the vacuum chamber
NOTICE
Contamination from operating fluid backflow
After the pump is switched off, the connected vacuum system can become contaminated.
► Vent the vacuum chamber, regardless of the chamber size, for 30 seconds.
► Shut off the intake line, after the pump is switched off during longer venting operations, with an
additional shut-off valve.
6.6.2 Maintaining the vacuum in the chamber
NOTICE
Contamination from operating fluid backflow
After the pump is switched off, the connected vacuum system can become contaminated.
► Because the safety valve of the pump is not suitable for longer-term sealing, install an additional
shut-off valve in the intake line.
► Shut off the intake line immediately after switching off the pump.
Operation
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