LEYBOLD 960702FP, Original Operating Instructions

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300419816_002_C1 - 11/2016 - © Leybold
1 Description
1.1 Design and function
The SOGEVAC
®
SV300 FP are single-stage, oil-sealed rotary vane pumps. The
anti-suck back valve, gas ballast valve (optional), exhaust filter, oil return circuit
and oil cooling oil are integrated functional elements. The pumps are driven by a
directly flanged motor.
The rotor mounted eccentrically in the pump cylinder has three vanes which di-
vide the pump chamber into several compartments. The volume of each changes
periodically with the rotation of the rotor.
As the rotor rotates, the intake portion of the pumping chamber expands and
sucks gas through the intake port. The gas passes through the dirt trap and the
open anti-suck back valve and enters the pump chamber. As the rotor rotates fur-
ther, the vane separates part of the pump chamber from the intake port. This part
of the pump chamber is reduced, and the gas is compressed. At slightly above
atmospheric pressure the gas is expelled from the chamber via the exhaust valve.
Oil injected into the pump chamber serves to seal, lubricate and cool the pump.
The oil entrained with the compressed gas is coarsely trapped in the oil case by
deflection. Then fine filtering occurs in the exhaust filter elements. The proportion
of oil in the exhaust gas is thus reduced below the visibility threshold (over 99 %
entrapment rate).
Oil trapped in the exhaust filters is returned to the inlet chamber via an oil return
transfer. To prevent gas flowing at atmospheric pressure from the oil reservoir
into the intake port, the oil return line is controlled by a float valve.
The oil cycle is maintained by the pressure difference existing between the oil
case (pressure above or equal to atmospheric pressure) and the intake port
(pressure below atmospheric pressure). The ball bearings are greased for 30 000
hours.
A fan running on the pump shaft generates the necessary cooling air. The oil
cools down through a radiator.
By opening the gas ballast valve, a controlled amount of air so called “gas ballast”
is admitted into the pump chamber. This gas ballast prevents condensation (up to
the limit of water vapor tolerance specified in the Technical Data) when pumping
condensable gases or vapors.
Unintentional venting of the vacuum chamber as well as oil suckback when shut-
ting down the pump are prevented by the integrated anti-suckback valve.
In applications where an oil-suckback must be avoided by all means, it is recom-
mended to install a dedicated valve.
Description