Series MNKA bearing pedestal assembly 4
Page 15
9250-003-en
Revision 01
TM 10458
Published 06/2022
6.3 Shutdown
♦
Close the discharge valve to the “minimum flow
rate” position.
♦
Switch the motor off.
♦
Close the discharge valve completely.
Only close the suction line if the pump
is to be drained or dismantled.
For all work on the machine, ensure
that the motor cannot be inadvertently
switched on.
If the pump is to be drained 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) during drain-
ing to prevent an explosive atmos-
phere.
It is recommended to wait 1 hour before the pump
is dismantled from the system to allow static
charge peaks to dissipate.
These measures are not necessary for pumps
with a conductive plastic lining.
When returning the pump to the manufacturer,
clean it very thoroughly.
See also
section 3.1
.
6.4 Restarting
When restarting the pump, make sure that,
depending on the extent of dismantling, all the
appropriate steps are repeated as described in
section 6.1
.
6.5 Improper operations and their
consequences (examples)
Improper methods of operation, even
for short periods, can result in serious
damage to the unit.
In terms of explosion protection, potential ignition
sources (overheating, electrostatic and induced
charges, mechanical and electrical sparks) can
result from these improper methods of operation.
This can only be prevented by observing the
proper use.
Pump is started up without liquid:
♦
The plain bearing in the pump can be de-
stroyed.
♦
Overheating can destroy other pump parts.
Operation with ruptured magnetic coupling:
♦
If there is no heat dissipation, damage to the
pump or drive rotor can occur.
Suction line is not opened or not opened
fully:
♦
Pump cavitates
—
material damage to pump
and plain bearings.
♦
Pump does not attain the required delivery
head or flow rate.
♦
Pump may be destroyed by overheating.
Discharge valve is closed too far:
♦
Pump may be destroyed by overheating.
♦
Axial thrust too great.
Discharge valve is opened too much:
♦
Pump may cavitate. Particularly severe with an
empty discharge line.
♦
Risk of pressure surge.
♦
Possible damage to the plain bearings.
♦
Magnetic coupling may rupture.
♦
Motor may be overloaded.
Suction valve and discharge are 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.
Admissible gas content exceeded:
♦
The flow may stop.
♦
To resume flow, stop the pump and vent it.
♦
Make sure that the gas content is not
exceeded as described in the intended use.
