Series SCK, Size 25-25-100
Page 15
9220-003-en
Revision 14
TM 10272
Edition 01/2021
6.3 Shutdown
Close discharge valve down to the position "minimum
flow rate"
Switch motor off.
Close discharge valve completely.
Only close the suction line if the pump is to be
evacuated or dismantled.
For all work on the machine, make sure that
the motor cannot be inadvertently switched
on.
If the pump is to be evacuated or flushed,
observe the local regulations.
If the pump has been operated with a
chargeable liquid, it must be filled with inert
gas (e.g. nitrogen) to prevent an explosive
atmosphere.
It is recommended to wait one hour before the pump
is dismantled from the plant to permit static peak
charges to be eliminated.
It is recommended to wait one hour before the pump
is dismantled from the plant to permit static peak
charges to be eliminated.
If the pump is returned to the manufacturer's, clean
the pump very thoroughly.
See also
Section 3.1
.
6.4 Restarting
When the pump is restarted, it must be ensured that
all the relative steps as described in
Section 6.1
are
repeated, depending on the progress of the shutdown
operation.
6.5 Improper operations and their
consequences (examples)
Improper operation, even for brief periods,
may result in serious damage to the unit.
In connection with explosion protection, potential
sources of ignition (overheating, electrostatic and
induced charges, mechanical and electric sparks) can
result from these inadmissible modes of operation;
their occurrence can only be prevented by adhering to
the intended use.
Pump is started up without medium :
The mechanical seal in the pump may be destroyed.
Other pump components may be destroyed due to
overheating.
Suction line not opened or not opened fully :
Pump is cavitating
–
material damage to pump and
plain bearings
Pump does not attain the required delivery head or
flow rate.
Pump may be destroyed due to overheating.
Discharge valve opened too much :
Pump may be destroyed due to overheating.
Excessive shaft deflection with consequences for the
mechanical seal.
Excessive bearing load with consequences for the
bearing service life.
Discharge valve closed too much :
Pump can cavitate. Particularly severe with an empty
discharge line.
Risk of pressure surge.
Motor may be overloaded.
Suction valve and discharge valve closed :
Destruction due to rapid overheating and sharp rise in
pressure.
Control of the pump with the suction valve :
Cavitation
–
the volume may only be regulated on the
discharge side. Cavitation
–
the volume may only
be regulated on the discharge side.
Suction valve and discharge valve closed :
Possible damage to the mechanical seal because
another pump can generate a pressure for which
the mechanical seal is not rated.
Overrun of the admissible gas content:
The flow may stop.
Switch pump and vent off for renewed conveyance.
Make sure that the gas content is not exceeded, as
described in the intended use.
