Richter RMA Series - Manual (Page 8)

Series RMA
Page 8
9475-050-en Revision 12
TM 7978 Edition 08/2010
2.6.7 Temperature limits
In the normal operating condition the highest
temperatures are to be expected at the
contact point shaft seal/shaft, on the inner
races of the ball bearings and, at high medium
temperatures, on the surface of the pump housing.
In the case of liquids >40 °C (>104 °F) the surface
temperature of the pump housing is generally lower
than the temperature of the liquid as the plastic lining
has an insulating effect.
If the pump is heated (e.g. heating jacket), it
must be ensured that the temperature classes
prescribed in the annex are observed.
The non 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.
Temperature class
acc. to EN 13463-1
Limit value of the
temperature of the liquid
PFA
T6
185 °F (85 °C)
not certified to ATEX
T5
212 °F (100 °C)
T4
275 °F (135 °C)
125 °C (257 °F) 1 2))
T3
392 °F (200 °C)
150 °C (302 °F)
T2
572 °F (300 °C)
150 °C (302 °F)
T1
842 °F (450 °C)
150 °C (302 °F)
1): Long life grease lubrication: T3
Oil bath lubrication: T4 only applies to operation up to
and including 50 Hz,
T3 above 50 Hz
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.
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 ball 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 may
prevent excessive temperatures due to hot-running
ball bearings, the drive magnet assembly striking 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. 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 requirements
and explosion protection provisions.