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2
I
NSTRUCTION
AND
SERVICE
MANUAL
VWZ 702 with closed circulation cooling
VWZ 702 with external cooling
1. Introduction
In the event of a pump being re-
turned to us, for whatever reason
(eg.repair) it must be free of all danger-
ous and toxic material. A corrosponding
certificate has to be presented!
Explosion proof standards for the plant in
which the vacuum pump will be installed,
are the responsibility of the customer and
should have the approval of the appropri-
ate factory inspectorate..
2. Applications
VWZ vacuum pumps are available for
handling a wide range of gases including
those which are extremely moist or ag-
gressive. They can also handle large quan-
tities of water vapour.
The ambient and suction tempera-
tures may be between 5 and 40° C.
For temperatures out of this range
please contact your supplier.
Suitable equipment should be fitted to
prevent slugs of liquid or solid parti-
cles being drawn into the pump. Han-
dling of explodible gases or vapours
only on request with our company.
Please contact your local Rietschle office
for advice.
For installation in explosion proof or
special areas,motors conforming to the
relevant standard must be fitted.
For installations that are higher
than 1000 m above sea level there
will be a loss in capacity. For further
advice please contact your supplier.
All applications where an unplanned
shut down of the pump could possibly
cause harm to persons or installations,
then the corresponding safety backup
system must be installed.
3. Variations and Construction
3.1 Variations
The type VWZ is available in 7 sizes but only sizes with a suction capacity of 700, 1000 and 1200 m
3
/hr will be handled herein.
All types will reach an ultimate vacuum of 0.5 mbar (absolute).
They are liquid cooled by:
1.
Closed circulation cooling (see fig. 1) by means of integral water/air heat exchanger, which in turn is cooled by its own motor
driven cooling fan. The cooling fan will be controlled by the thermostat.
2.
External cooling (see fig. 2) by means of the cooling water regulating valve, which is controlled according to the cooling water
outlet temperature.
