Series RMI-B
close-coupled design
Page
8
9430-055-en
Revision 00
TM 9886
Edition 03/2018
Dry-running cannot only occur with an insuf-
ficiently filled interior but also in the event of
high gas contents in the liquid medium.
Operation of the pump outside the admissible
operating range may also lead to dry-running (e.g.
due to evaporation in the interior).
2.6.7 Temperature limits
In the normal operating condition the highest
temperatures are to be expected on the sur-
face of the pump housing.
In the case of media >40° C the surface temperature
of the pump housing is generally lower than the tem-
perature 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 clas-
ses 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 (pos-
sibly regular cleaning). This prevents the
pump surface from heating to above the ad-
missible temperature.
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.
The following always applies: No inadmissible tem-
peratures may be introduced into the motor and the
specifications of the motor manufacturer and
VDMA/TVEI 24263 must be observed.
The temperature limits of the fluid given in
Table 2
only apply when motors are used where the motor
manufacturer permits at least the following surface
temperatures for the motor flange and motor shaft:
Table 1
Temperature
class
Motor flange
Motor shaft
T6
70 °C
70 °C
T5
70 °C
80 °C
T4
75 °C
85 °C
T3
75 °C
85 °C
T2
75 °C
85 °C
T1
75 °C
85 °C
Observe the data given by the engine manufacturers
or the VDMA / ZVEI 24263 about impermissible
ambient temperatures. The absence of this
information is to be expected to be at most 40 ° C.
Table 2
below indicates the admissible medium tem-
perature, depending on the pump design, as a func-
tion of the temperature class in accordance with EN
13463-1.
Table 2
Temperature class
acc. to EN 13463-1
Limit value of the tem-
perature of the liquid
PFA
T6
85 °C
75 °C
1)
T5
100 °C
90 °C
1)
T4
135 °C
125 °C
T3
200 °C
150 °C
T2
300 °C
150 °C
T1
450 °C
150 °C
1) 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 manu-
facturer.
For engines with the type of protection "increased
safety", only low surface temperatures are permitted
on the motor shaft or on the motor flange.
In these cases the max. permissible medium tempera-
ture is 20 K above the permissible surface tempera-
ture at the interfaces to the motor.
e. g.: max. motor shaft temperature: 60°C
max. motor flange temperature: 65°C
This results in a permissible medium temperature
for the pump of
80 °C (60 °C + 20K)
.
No information on the permissible ambient
temperature is to be assumed for a maximum of 40 °
C.
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.
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. cooling, heating) are
installed, check to see whether monitoring facilities
are required to ensure their function.
2.6.9 Electric peripheral equipment
Electric peripheral equipment, e.g. pressure,
temperature and flow sensors etc. must
comply with the prevailing safety require-
ments and explosion protection provisions.
Regular checks of the motor bearings in accordance
with the operating manual of the motor manufacturer.
Observe ATEX notes.
