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Page 47
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Operation
B722-40-880 Issue H
4.10
Bakeout
CAUTION
Pumps with ISO and NW style inlet flanges are not suitable for bakeout; only pumps with CF flanges must be used.
When baking the pump to above 70 °C at the inlet flange, the pump must be water cooled to prevent damage
to the bearing lubricant.
If the pump (and the vacuum system) are heated, the degassing process will speed up and the pump will reach
ultimate vacuum in the shortest possible time. Heating the pump will also prevent condensation of vapours inside
the pump.
The Edwards BX bakeout band may be used to heat the pump (refer to
). Fit the appropriate band around
the pump, just below the CF inlet flange. When baking the pump or the system, make sure that the temperature of
the inlet flange does not exceed 100 °C.
When baking the vacuum system, if the temperature of the system exceeds 200 °C, put a radiation shield between
the system and the pump. This radiation shield will reduce the heat radiated onto the pump rotor.
Typically, a bakeout of four hours is long enough to remove water condensation from the pump, however, the
bakeout time will depend on the amount of condensation in the pump and the vacuum system, and the ultimate
pressure desired.
WARNING
Do not touch the bakeout band or surrounding surfaces during the bakeout process as they will be
hot.
