Series SCK, Size 25-25-100
Page 16
9220-003-en
Revision 14
TM 10272
Edition 01/2021
7
Maintenance
7.1 Screw connections of the
housing
After initial loading by the operating pressure and
operating temperature the tightening torques of all
connection screws must be checked at the following
points:
housing flange
suction flange
discharge flange
See also
Section 6.1.2, para. 1
.
Other inspections are to be performed regularly,
depending on the operating requirements.
7.2 Bearing pedestal
The temperature of the bearing pedestal is
not to exceed more than 70 °C and under
no circumstances 80 °C.
If higher temperatures do occur, call in qualified staff
without delay. If this is not possible, the pump must be
shut down and taken out of service.
In many cases a vibration measurement is recom-
mended to detect bearing wear in good time.
In potentially explosive works it is
advisable to monitor the condition of
the rolling bearings
7.2.1 Long life grease lubrication
Grease-filled rolling bearings of type 2RS are fitted as
standard. The grease based on polyurea thickener
and ester oil has the designation WT. The permissible
temperature range lies between -40°C and +160°C.
The roller bearings are designed for a service life L
10
of >35,000 hours.
The service life of the grease fill-
ing guaranteed by the bearing manufacturers is
shown in the following table. Depending on the
degree of contamination, the service life of the
grease is reduced.
Size
Bearing size > Service life
Group 0
6005-2RS WT / 35000 hr*
*
at bearing temperature <70 °C
If the pump is serviced, it is recommended to also replace
the bearings as a precaution.
See
Fig. 10
.
Fig. 6
7.2.2 Oil bath lubrication
With an expected bearing temperature of about 70°C
we recommend a mineral oil with the following charac-
teristics:
Viscosity index : approx. 85
Kinematic viscosity at 40°C : approx.
A fully synthetic gear oil to ISO VG 220 is to be used
for temperatures below
–
20 °C.
Replacing the bearings:
The ball bearings are
designed for an L10 service life of >35.000 hours.
We recommend 35.000 working hours respectively
every 4 years a change of bearing should be made.
Oil changes:
1x per year at bearing temperatures of
about 70 °C.
At higher temperatures more frequently in accordance
with the regulations.
When the pump is serviced, it is recommended to
replace the bearings and shaft seals as a precaution
and to pour in fresh oil.
Oil level check
: The oil level is to be regularly
checked on the constant level oiler
638/1
to ensure
safe operation.
It must be ensured that there is always oil in the con-
stant level oiler; it must under no circumstances be
completely drained.
7.3 Mechanical seals
The regulations of the mechanical seal manufacturer
must always be observed.
See also the relevant supplementary installation and
operating manual for mechanical seals.
7.4 Cleaning
Care must be taken when cleaning the pump to
ensure that it is not exposed to a strong water jet.
The ingress of water into the bearing pedestal will
substantially impair ball bearing lubrication.
7.5 Stand-by pumps
If a pump is on stand-by, it is to be started up from
time to time.
This operation is to be performed more often for
pumps which are exposed to very strong vibrations
from the plant.
When dismantling the pump from the plant, drain it,
thoroughly clean it, seal with flange covers and store
in accordance with the instructions.
