6
Rotary Vane Vacuum Pumps UNO 005 A/2.5 A, DUO 2.5 A/AC
1
Vacuum connection
8
Support stand
2
Exhaust connection
9
Casing
3
Operating fluid filler screw
35
Casing seal
4
Operating fluid drain screw
44
Base plate
5
Sight glass
48
O-ring
6
Motor
49
O-ring
7
Gas ballast valve
3/48
1
2
9
4/49 5
44
35 7
8
6
V
4. Operations
4.1. Filling Up And Checking The Operating
Fluid
Standard version pumps are tested with opera-
ting fluid P3. Guarantees relating to attainment
of final pressures and trouble free functioning
apply only providing this operating fluid is used.
The delivery consignment contains sufficient operating fluid
for one filling.
Pumps for special applications (e.g. for pumping corrosive
gases) can be operated with special operating fluids such as
F5, C100 and other Pfeiffer operating fluids. The use of such
operating fluids requires prior authorisation from the
manufacturer.
P3 must be disposed of in accordance with local waste dispo-
sal regulations.
➡
Remove operating fluid filler screw 3.
➡
Fill up with operating fluid so that the level is between the
two markings on the sight glass or on the casing (for
pumps with replaceable sight glass ; also refer to rating
plate for correct quantity.
– The minimum level is the lower marking on sight glass 5.
➡
Replace operating fluid filler screw 3; be careful with
O-ring 48.
➡
Check operating fluid level only when the pump is warm
and running and vacuum connection 1 and gas ballast
valve 7 and operating fluid filler screw are closed.
ACHTUNG
– In non-stop operations check operating fluid daily,
otherwise whenever the pump is switched on;
topping up pump fluid is possible when the pump is in
final vacuum operations.
If there is a noticeable loss of pump fluid, the
casing and the radial shaft seals should be
checked for leaks (see Service Instructions).
4.2. Switching The Pump ON And OFF
The pump can be switched ON and OFF in any pressure
range. Maximum exhaust pressure 1.5 bar (absolute). Lowest
start-up temperature, in compliance with German Industrial
Standard DIN 28 426: +12°C.
On switching OFF (intake pressure < 750 mbar) the built-in
high vacuum safety valve to the vacuum chamber closes
automatically and the pump is vented.
The Working Of The High Vacuum Safety Valve
The automatically operating high vacuum safety valve 20 is
open when the equipment is vented. When the pump is
switched on, air intake is shut off via hydraulic pump 53
integrated in the pumping system and the safety valve
remains in the open position owing to the action of the
pressure spring.
At intentional or unintentional pump standstills, hydraulic
valve 23 opens the air intake owing to absence of hydraulic
pressure and presses valve head 24 against the vacuum side
by virtue of the air streaming in. The system closes vacuum
tight and simultaneously the pump is vented.
When the vacuum pump is switched on again, the intake of
air is shut off by hydraulic valve 23 and the inner area of the
high vacuum safety valve is evacuated. If the pressure in the
valve has fallen far enough that the force of spring 27 is suffi-
cient to press valve head 24 against the pressure prevailing in
the system, the valve opens.
4.3. Pumping Dry Gases And Vapours
No special measures are necessary providing the correct
pump version is being operated (selection of operating fluid,
materials etc.).
ACHTUNG
Sight glass 5 with operating fluid level for the first filling and
during operation
Markings
on casing
