5
GA02329_002_03 - 01/2010 - © Oerlikon Leybold Vacuum
1 Description
Sogevac
®
pumps are designed for pumping of inert gases in the range of
rough vacuum, between atmospheric pressure and ultimate pressure of the
pump.
When removing condensable vapors, periodic opening of the gas ballast
valve is required.
1.1
Principle of operation
The Sogevac
®
pumps SV40 BI are single-stage oil-sealed rotary vane
vacuum pumps.
The rotor, having three slots in which the vanes are sliding, is eccentrically
installed in a pump cylinder (stator).
The vanes separate the interior space into 3 chambers. The volume of these
chambers varies with the rotation of the rotor.
The gas sucked into the inlet chamber is compressed and then pushed out
at the exhaust valve.
The oil injected in the inlet chamber guarantees the air-tightness, the
lubrication and cooling of the pump. It is dragged off by the compressed
gases and roughly separated by gravity when entering in the oil sump. A fine
separation is then operated in the exhaust filter. An internal transfer pushes
the collected oil back into the vacuum generator, the transfer is operated by
a float valve to avoid atmospheric air coming from the oil casing to the inlet
of the pump when no oil is present in the recovery system.
The oil circulation functions by differential pressures.
The pumps are equipped with a gas ballast valve for pumping condensable
vapors.
The anti suckback valve at the inlet flange avoids oil coming back into the
inlet line when the pump is stopped. This is valid for working pressures below
100 mbar and under the condition that the valve is kept clean and in good
condition. The anti suck
back valve is not a safety valve. If oil back flowing is to be avoided by all
means, it is necessary to mount a separate safety valve on the pump inlet.
Description
