RS – Multi-Stage, I-280
Centrifugal Pump 280 – 16.03.EN
5
Pump operation with the shut-off valves in
the suction and/or discharge pipes closed is not
permitted.
CAUTION
In this condition, there is a risk of the pump
casing taking on high surface temperatures
after a very short time, due to a rapid
temperature rise in the pumped fluid inside the
pump. Additionally, the resulting rapid pressure
build-up inside the pump may cause excessive
stresses on the pump materials or even
bursting.
The minimum flows calculated in Section VIII,
Paragraph E, refer to water and water-like liquids.
Longer operating periods with these liquids and at the
flow rates indicated will not cause an additional increase
in the temperatures on the pump surface. However, if
the physical properties of the fluids handled are different
from water, it is essential to check if an additional heat
build-up may occur and if the minimum flow rate must
therefore be increased.
To check, proceed as described in Section VIII,
Paragraph E.
In addition, the instructions given in Section VIII of this
operating manual must be observed.
Mechanical seals may exceed the
specified temperature limits if run dry. Dry
running may not only result from an
inadequately filled seal chamber, but also from
excessive gas content in the fluid handled.
Pump operation outside its specified operating range
may also result in dry running.
K.5 Temperature Limits.
In normal pump operation, the highest
temperatures are to be expected on the surface
of the pump casing, at the shaft seal and in the
ball bearing areas. The surface temperature at
the pump casing corresponds to the
temperature of the fluid handled.
If the pump is heated, it must be ensured that the
temperature classes stipulated for the plant are
observed.
In the ball bearing bracket area, the unit surfaces must
be freely exposed to the atmosphere and the fan inlet
flow must be unimpeded.
In any case, responsibility for compliance
with the specified fluid temperature (operating
temperature) lies with the plant operator. The
maximum permissible fluid temperature
depends on the temperature class to be
complied with.
Table 1 below lists the temperature classes to EN
13463-1 and the resulting theoretical temperature limits
of the fluid handled. In stipulating these temperatures,
any temperature rise in the shaft seal area has already
been taken into account.
Table 1. Fluid Temperature Limits
Temperature class
to EN 13463-1:
Temperature limit of
fluid handled
CAUTION
The permissible operating temperature of the
pump in question is indicated on the data
sheet. If the pump is to be operated at a higher
temperature, the data sheet is missing or if the
pump is part of a pool of pumps, the maximum
permissible operating temperature must be
enquired from the pump manufacturer.
Based on an ambient temperature of 104˚ Fahrenheit
(F) [40˚ Celsius (C)] and proper maintenance and
operation, compliance with temperature class T4 is
warranted in the area of the rolling element ball
bearings. A special design is required for compliance
with temperature class T6 in the ball bearing area. In
such cases, and if ambient temperature exceeds 104˚F
(40˚C), contact the manufacturer.
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