Series MNK pedestal group 4
Page
8
9230-003-en
Revision 19
TM 10458
Edition 06/2022
2.6.7 Temperature limits
In the normal operating condition, the highest temper-
atures are to be expected at the contact point shaft
seal/shaft, on the inner races of the rolling bearings
and, at high medium temperatures, on surface of the
pump housing.
We would like to point out that the sur-
face temperature of the pump housing is
only slightly below the medium tempera-
ture.
If the pump is heated (e.g. heating jacket), it must be
ensured that the temperature classes prescribed in the
annex are observed.
The not heated pump surface must have free contact
with the environment.
When operating the pump, make sure that
an excessive deposit of dust is avoided
(possibly regular cleaning). This prevents
the pump surface from heating to above
the admissible temperature.
Table 1
below indicates the admissible medium tem-
perature, depending on the pump design, as a DIN
EN ISO 80079-36. (see appendix to the operating
manual Operational: limits 9230-00-3041)
Table 1
Temperature class
as per
DIN EN ISO
80079-36
Limit value of the pumped
liquid temperature
Lining material
PFA/PTFE
Can material
2)
CFK-F
T4
(135 °C)
125 °C
1)
T3
(200 °C)
180 °C
3)
1) Long life grease-lubricated rolling bearings: No restrictions.
T4 only applies to operation up to 1750 rpm
2) The can material has been list in the data sheet.
3) If the temperature of the pumped liquid exceeds 180 °C, the
ATEX approval becomes permanently invalid. The ATEX plate
must be removed immediately by the operator. A new ATEX
approval can only be issued by a judge. For this purpose, the
pump can be sent in for inspection.
The plant customer must ensure that the
prescribed operating temperature is observed. The
maximum admissible temperature of the liquid
medium at the pump inlet depends on the
temperature class and the selected lining material
required in each case.
2.6.8 Maintenance
To achieve safe and reliable operation, it
must be ensured in inspections at regular
intervals that the unit is properly serviced
and kept in technically perfect order.
Example: Functioning of the rolling bearings. The mode
of operation and operating conditions largely determine
the actual service life that can be attained.
Regular checks of the bearing pedestal area can pre-
vent excessive temperatures due to hot-running rolling
bearings, collision of the drive magnet assembly
against the lantern or even defective bearing seals.
See
Section 7.2
.
In regard to media containing solids, the maintenance
intervals must be set by the operator in accordance
with the conditions of operation.
If auxiliary systems (e.g. external flushing, cooling,
heating) are installed, a check must be made to see
whether monitoring facilities are required to safeguard
their operation.
2.6.9 Electric peripheral equipment
Electric
peripheral
equipment,
e.g.
pressure, temperature and flow sensors
etc. must comply with the prevailing safety
requirements and explosion protection
provisions.
