39
Table 18: Key
temperatures on the pump surface. However, if the physical properties of the fluids handled are
different from water, the calculation formula below must be used to check if an additional heat
build-up may lead to a dangerous temperature increase at the pump surface. If necessary, the
minimum flow must be increased.
6.2.4 Density of the fluid handled
The power input of the pump increases in proportion to the density of the fluid
handled.
6.2.5 Abrasive fluids
Do not exceed the maximum permissible solids content specified in the data sheet.
When the pump handles fluids containing abrasive substances, increased wear of
the hydraulic system and the shaft seal are to be expected. In this case, reduce the
intervals commonly recommended for servicing and maintenance.
6.3 Shutdown/storage/preservation
6.3.1 Measures to be taken for shutdown
The pump (set) remains installed
Sufficient fluid is supplied for the operation check run of the pump.
1. Start up the pump (set) regularly between once a month and once every three
months for approximately five minutes during prolonged shutdown periods. This
will prevent the formation of deposits within the pump and the pump intake area.
The pump (set) is removed from the pipe and stored
The pump has been properly drained ( Section 7.3 Page 47) and the safety
instructions for dismantling the pump have been observed. ( Section 7.4.1 Page47)
1. Spray-coat the inside wall of the pump casing, and in particular the impeller
clearanceareas, with a preservative.
2. Spray the preservative through the suction and discharge nozzles.
It is advisable to then close the pump nozzles (e.g. with plastic caps or similar).
Symbol
Description
Unit
c
Specific heat capacity
J/kg K
g
Gravitational constant
m/s²
H
Pump head
m
T
f
Temperature of the fluid handled
°C
T
o
Temperature at the casing surface
Pump efficiency at duty point
Temperature difference
°C
_
°C
C AUTION
Impermissibly high density of the fluid handled
Motor overload!
Observe the information on fluid density indicated in the data sheet.
Make sure the power reserve of the motor is sufficient.
6 Commissioning/Start-up/Shutdown
