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Technical Information
Pump Purging and Venting
How to Purge the Turbo-V 3K-G Pump
To supply the inert purge gas (e. g. nitrogen) to the pump through the
purge port, connect a gas purge line to the pump.
The purging device automatically provides about 20 sccm when fed
with 1 bar (14 psi) absolute (atmospheric pressure).
To prevent bearing damage, Agilent suggests a minimum purge gas flow rate of
CAUTION!
20 sccm (0.33 mbar l/s). This value can be exceeded, according to the process
requirements. Please contact Vari-an for specific applications.
How to Vent the Turbo-V 3K-G Pump
The recommended procedure to vent the system is described in the
following points:
1
2
Leaving the Turbo-V 3K-G pump and the backing pump running and the purge
gas flowing, wait for enough time to evacuate the process gases from the system
(e.g. to reach the typical basic process pressure).
3
Then close the gate valve connecting the Turbo pump to the chamber (if present)
and the valve connecting the Turbo pump to the rough pump (if present).
4
Turn off the Turbo pump by sending the STOP signal to the controller.
5
The Turbo-V 3K-G pump will automatically start the "Controlled Venting
Procedure" by default. This means that the integrated vent valve will allow a flow
of venting gas (e.g. Ni-trogen), automatically actuated by the controller, in order
to slow the rotor down in controlled manner to a rotational frequency of 100 Hz
by adopting the SSR (Stop Speed Reading) function. All other system operations
should be carried out at rotational frequencies of less than 100 Hz.
6
When the Turbo-V 3K-G pump and the backing pump are stopped and the system
is at atmospheric pressure, for a better bearing protection it is advisable to leave
the purge gas flowing into the Turbo-V pump, with the chamber or the Turbo-V
vent valve opened, to avoid system overpressures.
364/374
Close the process gases flowing into the system before sending
the STOP signal to the Turbo-V 3K-G pump.
Turbo-V 3K-G Pumping System User Manual / 87-901-011-01
(C)
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