Series MNKA bearing pedestal assembly 4
Page 16
9250-003-en
Revision 01
TM 10458
Published 06/2022
7
Maintenance
7.1 Housing screw connections
After initial loading by the operating pressure and
operating temperature, the tightening torques of
all connection screws are to be checked at the
following points:
♦
Housing flange
♦
Suction flange
♦
Discharge flange
See also
section 6.1.1, item 1
.
Further checks are to be carried out at regular
intervals
depending
on
the
operating
requirements.
7.2 Bearing pedestal
The temperature of the bearing ped-
estal should not exceed 158 °F
(70 °C) and must never exceed
176 °F (80 °C).
In the event of higher temperatures, take the pump
out of operation immediately and contact qualified
personnel.
In some cases, vibration measurement is
recommended to detect rolling bearing wear in
good time.
7.2.1 Rolling bearings with long-life
grease lubrication
Grease-filled rolling bearings of type 2RS are fit-
ted as standard. The grease is lithium saponified.
The permissible temperature range lies between -
40 °F (-40 °C) and 320 °F (+160 °C).
The rolling bearings are designed for an L10 ser-
vice life of >35,000 hours.
The service life of the
grease filling guaranteed by the bearing
manufacturers is shown in the following table.
Size
Bearing size > service life
Group 4
6314-2RS / 15000 hr*
* at bearing temperature <158 °F (<70 °C)
If the pump is serviced, it is recommended that the
bearings are replaced as a precautionary meas-
ure.
In
potentially
explosive
atmospheres it is advisable to
monitor the condition of the
bearings.
7.2.2 Oil bath lubrication
We recommend a mineral oil with the following
characteristics for an expected bearing pedestal
temperature of up to 158 °F (70 °C)
:
Viscosity index: Approx. 85
Kinematic viscosity at 104 °F (40 °C)
:
s
2
mm
40
.
ca
A fully synthetic gear oil to ISO VG 220 is to be
used for temperatures below -68 °F (-20 °C).
Replacing the bearings:
The roller bearings are
designed for a service life L
10
of >35,000 hours.
We recommend changing the bearings after
35,000 working hours or every 4 years.
Oil change:
1 x per year at bearing pedestal tem-
peratures of up to 158 °F (70 °C).
Every 6 months at bearing pedestal temperatures
of up to 158 °F (70 °C).
More frequently at higher temperatures as speci-
fied.
If the pump is serviced, it is advisable to replace
the bearings and shaft seals as a precautionary
measure and to fill with new oil.
Oil level check:
For safe operation, the oil level
must be checked regularly at the
638/1
oil level
controller.
The oil level controller must always contain oil; it
must never be completely empty.
In potentially explosive atmos-
pheres it is advisable to monitor
the condition of the bearings.
If there is any reason to suspect that water spray
may have entered the bearing pedestal, then an
oil change must be carried out immediately. Even
small amounts of water in the oil will reduce the
life of the rolling bearings to a fraction of the nor-
mal life expectancy.
If the pump is serviced, it is advisable to replace
the bearings and shaft seals as a precautionary
measure and to fill with new 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
would substantially impair bearing lubrication.
