5.4 Connecting the high vacuum side
5.4.1 Designing the counter flange
NOTICE
Risk of damage due to incorrect counter flange design
Unevenness on the operator-side counter flange results in stresses in the vacuum pump housing,
even when properly attached. This can produce leakage or negative changes in running characteris-
tics.
► Adhere to the shape tolerances for the counter flange.
► Observe the maximum flatness deviations over the entire surface.
Superstructural parts and fittings on the high vacuum connection
Installing superstructural parts and fittings to the high vacuum connection is the responsibil-
ity of the operating company. The loading capacity of the high vacuum flange is specific for
the turbopump used.
● The total weight of superstructural parts must not exceed the maximum axial values
specified.
● Make sure that all the torques generated if the rotor blocks suddenly, are absorbed by
the system on the operator side and the high vacuum connection.
● Only use the approved mounting kits of Pfeiffer Vacuum for the high vacuum connec-
tion of the turbopump.
Parameter
HiCube 80 Pro
HiCube 300 Pro
HiCube 400 Pro
HiCube 700 Pro
Maximum torque occurring in the event of
a burst
1)
620 Nm
2000 Nm
4200 Nm
4200 Nm
Maximum permissible axial load on the
high vacuum flange
2)
1000 N
(equivalent to
100 kg)
1000 N
(equivalent to
100 kg)
1000 N
(equivalent to
100 kg)
1000 N
(equivalent to
100 kg)
Flatness
± 0.05 mm
± 0.05 mm
± 0.05 mm
± 0.05 mm
Minimum tensile strength of the flange
material in all operating states in relation
to the engagement depth of the fixing
screws
170 N/mm
2
at 2.5 x d
270 N/mm
2
at 1.5 x d
170 N/mm
2
at 2.5 x d
270 N/mm
2
at 1.5 x d
170 N/mm
2
at 2.5 x d
270 N/mm
2
at 1.5 x d
170 N/mm
2
at 2.5 x d
270 N/mm
2
at 1.5 x d
Maximum permissible surrounding mag-
netic field
3.3 mT
5.5 mT
6.0 mT
6.0 mT
Maximum permissible irradiated thermal
output
3.0 W
8.0 W
14.0 W
14.0 W
Maximum permissible rotor temperature
90 °C
90 °C
90 °C
90 °C
Tbl. 5:
Requirements for the dimensioning of high vacuum connection supplied by the cus-
tomer
5.4.2 Use splinter shield or protective screen
Pfeiffer Vacuum centering rings with splinter shield or protective screen in the high vacuum flange pro-
tect the turbopump against foreign matter from the vacuum chamber. The pumping speed of the turbo-
pump reduces according to the passage guide values and the size of the high vacuum flange.
Flange size
Reduced pumping speed in % for the gas type
H
2
He
N
2
Ar
Splinter shield DN 40
6
9
17
18
1)
The theoretically calculated torque in the event of a burst (rotor shaft breakage) according to ISO 27892 was
not reached in any experimental test.
2)
A one-sided load is not permitted.
Installation
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