Richter MNK Series - Manual (Page 8)

Series MNK
Page 8
9230-050-en Revision 11
TM 7903 Edition 07/2010
2.6.7 Temperature limits
In normal operating mode the highest
temperatures are to be expected at the
contact point shaft seal/shaft (only with oil
bath lubrication), on the inner races of the rolling
bearings and at high medium temperatures on the
surface of the pump housing.
We would like to point out that, under extreme
operating (medium temperature > 160°C) and
ambient conditions (ambient temperature
>30 °C), temperatures of over 130°C may arise on the
surface of the pump housing.
In the case of media >40° C the surface temperature
of the pump housing is generally lower than the
temperature of the medium as the plastic lining acts
as insulation.
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
temperature, depending on the pump design, as a
function of the temperature class in accordance with
EN 13463-1.
Table 1
Temperature class acc.
to EN 13463-1
Limit value of the temperature of the liquid
Lining material PP PE-UHMW PFA/PTFE
Can material 4) CFK-F CFK-F CFK-F CFK-H CFK-Polyimid
T6 (85 °C)
not certified to ATEX
T5 (100 °C)
T4 (135 °C) 80 °C 1) 90 °C 1) 125 °C 1) 2) 125 °C 1) 2) 125 °C 1) 2)
T3 (200 °C) 80 °C 90 °C 150 °C 180 °C 180 °C 3)
T2 (300 °C) 80 °C 90 °C 150 °C 180 °C 180 °C 3)
T1 (450 °C) 80 °C 90 °C 150 °C 180 °C 180 °C 3)
1) Long life grease lubrication: no restriction.
Oil bath lubrication: standard version with shaft seal
T4 only applies to operation up to and
including 50 Hz,
T3 above 50 Hz
T4 labyrinth seal (special design)
2) The limit values specified for the temperature of the medium at
the pump inlet are determined for the most unfavourable case
(high speed, low flow, low heat capacity of the medium, ....).
Under favourable operating conditions the limit values specified
may be increased by up to 5 K after consultation with the
manufacturer.
3) Consult the manufacturer for higher limit values.
4) The can material has been list in the data sheet.
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.
It is only possible to observe the temperature class T4
with oil lubrication with the standard rotary shaft seal
during operation up to and including 50 Hz. T3 applies
to operation above 50 Hz with the standard rotary
shaft seal.
The special version with a labyrinth seal permits
operation in T4 regardless of the speed.
2.6.8 Maintenance
For safe and reliable operation, it must be
ensured with regular inspection intervals that
the unit is properly serviced and kept in a
perfect technical condition.
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
prevent 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.