Agilent Technologies 949-9360, Руководство пользователя

Страница: 55 / 102

Technical Information
Anti-Suckback Device
5
HS452, HS652 Rotary Vane Pumps User Manual / 87-900-978-01 (H) 55/102
Anti-Suckback Device
The pump is equipped with a special anti-suckback device to avoid
air pressure rises and/or oil back-flow towards the evacuated vessel
when the pump is switched off. This device has a shutter which
automatically closes the suction duct.
In this way the pump and vacuum system are completely isolated
from each other and air can enter the pump without any risk for the
vacuum produced in the system.
The device includes some special features, namely:
ƒ
drive obtained avoiding any form of contamination of the inlet
duct by fluids (oil and/or air) used to command the shutter.
Thanks to this, when the pump is started again, the pump-down
to vacuum conditions is extremely fast as these contaminants are
not present and no degassing is therefore required;
ƒ suction flange maintained closed even when the pump is idle, so
that pollutants cannot enter from the environment and no oil can
overflow from the pump.
Figure 4 Pump main asssemblies