Series MNK pedestal group 4
Page
16
9230-003-en
Revision 19
TM 10458
Edition 06/2022
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 6.1.1, para. 1
.
7.2 Bearing pedestal
The temperature of the bearing pedestal
is not to exceed more than 70 °C and un-
der no circumstances 80 °C.
At higher temperatures, take the pump off immediately
and consult a specialized technician.
At higher temperatures, call in qualified staff without
delay.
7.2.1 Long life grease lubricated rolling
bearings
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 tem-
perature 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 filling
guaranteed by the bearing manufacturers is shown in the
following table.
Depending on the degree of contam-
ination, the service life of the grease is reduced.
Size
Bearing size > Service life
Group 4
6314-2RS WT/ 35 000 hr*
* at bearing temperature <70 °C
If the pump is serviced, it is recommended to also re-
place the bearings as a precaution.
In potentially explosive works it is
advisable to monitor the condition
of the rolling bearings
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
:
s
2
mm
40
.
appr
A fully synthetic gear oil to ISO VG 220 is to be used
for temperatures below
–
20
Replacing the bearings:
The ball bearings are
designed for an L
10
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 re-
place 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.
In potentially explosive works it is advisable to monitor
the condition of the rolling bearings
In potentially explosive works it is
advisable to monitor the condition
of the rolling bearings
If there is a suspicion that splash water could have en-
tered the bearing pedestal, the oil must be replaced im-
mediately. Even small amounts of water in the oil re-
duce the service life of the rolling bearings to a fraction
of the normal service life.
When the pump is serviced, it is recommended to
replace the bearings and shaft seals as a precaution
and to pour in fresh oil.
7.3 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 bearing lubrication.
