Venting the Turbo-V 750/850 TwisTorr Pumping System
After the turbopump is switched off, it must be vented to avoid
contamination due to particles streaming back from the fore-vacuum
section. The recommended procedures to vent the system are
described in the following.
Venting Procedure without Contaminants and/or
Corrosive Gases – Manually Venting
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To safely slow down the pump use a venting flow able to decelerate the rotor at
CAUTION!
a rate lower than 5 Hz/s. To monitor the deceleration rate activate the "Stop
Speed Reading" function by serial line (WIN 167) and read the pump rotational
speed through WIN 232.
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Turbo-V 750/850 TwisTorr User Manual / 87-901-020-01
Venting the Turbo-V 750/850 TwisTorr Pumping System
Close the process gases flowing into the sys-tem before sending
the STOP signal to the Turbo-V 750/850 TwisTorr Pumping
System;
Close the gate valve connecting the Turbo pump to the chamber
(if present);
Switch off the backing pump or close a fore-vacuum valve (if
present);
Turn off the Turbo pump by sending the STOP signal to the
controller;
Open the Turbo-V vent port (positioned on the envelope) slowly
until to reach atmospheric pressure in the system;
For water cooling: shut off the water supply.
Technical Information
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