Manual venting
Manual venting describes the standard process for venting the turbo pumping station.
1. Ensure that the vacuum system is shut down.
2. Open the black venting screw on the turbopump by one revolution maximum.
3. Wait for pressure equalization to atmospheric pressure in the vacuum system.
4. Close the venting screw again.
Use a Pfeiffer Vacuum venting valve
The Pfeiffer Vacuum venting valve is an optional accessory for installation on the turbopump.
The venting valve is normally closed. Control is via the turbopump electronic drive unit, and configura-
tion of parameters
[P:012]
and
[P:030]
. In the event of a power failure, the turbopump continues to de-
liver sufficient energy during its run-down period to initiate a proper venting process. When power is re-
stored, the venting process is interrupted.
► Switch off the turbopump.
– The venting process starts automatically.
Venting speed [P:720] Venting duration [P:721] Venting duration in the event of a power
failure
50 % of rated speed
3600 s
3600 s
Tbl. 9:
Factory settings for delayed venting in turbopumps
General information for fast venting
We recommend fast venting of larger volumes in 4 steps.
1. Use a Pfeiffer Vacuum venting valve for the turbopump, or match the valve cross-section to the
size of the recipient and maximum venting rate.
2. Vent the vacuum system with a maximum rate of pressure rise of
15 hPa/s
for a duration of 20
seconds.
3. Then vent the system with a second venting valve of any size; for example, directly at the vacuum
chamber.
4. Wait for pressure equalization to atmospheric pressure in the vacuum system.
Operation
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