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3.6. Special Models
Helium Tight Models
– Helium tight models are distinguished by their high level
tightness to the atmosphere.
– Helium tight models are operated, as standard, with opera-
ting medium P3.
– The rotor shaft is sealed with an additional radial shaft
seal. The cavity between the radial shaft seals 133 is filled
with operating medium and is supplied by the oiler 136.
– If the gas ballast valve 45 is not available, the opening
should be closed with the locking screw 169 or a special
gas ballast valve with dosing device and hose connection
for flushing gas is available (on request).
Corrosive Gas Models
– Corrosive gas models are manufactured with special
materials.
– The rotor shaft of both versions is sealed with an
additional radial shaft seal. The cavity between the radial
shaft seals 118 and 133 is filled with operating medium and
is supplied by the oiler 136.
– If the gas ballast valve 45 is not available, the opening
should be closed with the locking screw 169 or a special
gas ballast valve with dosing device and hose connection
for flushing gas is available (on request).
– Corrosive gas models are operated, as standard, with
synthetic operating medium F5.
