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. 12:
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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