Speed of the Pressure Rise
All turbomolecular pumps may be vented at full speed. However, the pres-
sure must not increase faster than specified through the pressure rise curve.
The pump must be vented significantly slower when there is the risk of par-
ticles entering into the pump from the process. During venting, the flow must
be of the laminar type in both the vacuum chamber and the turbomolecular
pump.
The speed of the pressure rise during venting of the running pump will greatly
influence the load on the rotor/stator pack and the bearings. The slower the
pump is vented, the longer the service life of the bearings will be.
The pump must not be vented to pressures above atmospheric pressure.
Operation
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GA05118_1502 - 12/2006 - © Oerlikon Leybold Vacuum
Speed
Pressure rise curve
Particles
