GA 05.123/3.02 - 12/95
Description
6
Key to Fig. 4
1 Purge gas connecting flange
2 Throttle nozzle
3 Sintered metal filter
4 O-rings
5 Diaphragm filter
6 Hose nozzle
7 Venting bypass
8 Solenoid valve
9 Plug
10 Pin
Fig. 4 Purge gas and venting valve fitted to a
TURBOVAC (schematic)
1.3 Purge gas
We recommend a purge gas and venting valve for purge
gas operation. It is a throttle for supplying a dosed quan-
tity of purge gas to turbomolecular pumps, and a venting
valve for turbomolecular pumps.
It is not suitable for shutting off the purge gas con-
nection of a TURBOVAC.
Nitrogen, argon or dry air are used as the purge gas. The
purge gas flows through the filter and the throttle nozzle,
into the purge gas connection (4/1) of the turbomolecular
pump. The motor and bearing area of the pump is pro-
tected with purge gas.
Since the motor and bearing area is connected to the
forevacuum area only by a narrow slit, a pressure higher
can build up there than in the forevacuum area. This
results in continuous gas flow from the motor area to the
forevacuum area. The gas flow prevents aggressive,
corrosive gases or dust entering the motor and bearing
area.
1.4 Standard specification
The turbomolecular pumps are shipped complete, seal-
ed in a PE bag containing a desiccant.
The maximum effective life of the desiccant is one year.
The electronic frequency converter as well as the con-
nection lines required for operation must be ordered sep-
arately.
High-vacuum connection ISO-K
Splinter guard, centering ring with FPM sealing ring,
outer ring.
High-vacuum connection ANSI
Splinter guard, FPM sealing ring.
Forevacuum connection port
Centering ring with FPM O-ring and clamping ring.
Both the purge gas port and the venting port are blanked
off for shipping.
High-vacuum and fore-vacuum connection are sealed
with plastic caps for transport.
PE = Polyethylen
FPM = Fluor caoutchouc, resistant to temperatures of up to 150
°
C
(302
°
F)
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