Series SCK, Size 25-25-100
Page 20
9220-003-en
Revision 14
TM 10272
Edition 01/2021
8
Malfunctions
Faults may result from inadmissible modes
of operation. Such improper operation
–
even brief ones
–
may cause serious dam-
age 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.
See also
Section 6.5
.
Should there be any uncertainty about the remedy to
be applied, please inquire at the in-house pump office
or at the pump manufacturer's.
No delivery :
Is the pump filled and vented?
Is the suction line open, vented, cleaned and correctly
laid?
Is the discharge line open, vented, cleaned and cor-
rectly laid?
Is the geodetic head too high?
Is air being drawn in?
Flow rate too low :
Have the pump, suction line and discharge line been
completely vented, filled and cleaned?
Have any strainers installed been cleaned?
Are all shut-off devices open?
Is the geodetic head too high?
Is the NPSHA too low or the NPSHR too high?
Are the pipe resistances too high?
Is the viscosity too high?
Is the direction of rotation correct?
Is the speed too low or the impeller diameter too
small?
Are pump parts worn?
Gas in the medium?
Flow rate too high :
Is the geodetic head too low?
Are the pipe or nozzle resistances too low?
Is the pump speed too low or the impeller diameter
too large?
Delivery pressure too high :
Is the speed too high or the impeller diameter too
large?
Is the density too high?
Motor consumes too much electricity :
Is the flow rate, density or viscosity too high?
Is the speed too high or the impeller diameter too
large?
Is the coupling correctly aligned?
Can the pump shaft be turned properly?
Pump does not run smoothly or creates nois-
es :
Is the coupling correctly aligned?
Are the coupling elements worn?
Are the rolling bearings damaged?
Are parts of the hydraulics damaged?
Is the flow rate too low or too high?
Is the impeller balanced?
Is the pump twisted?
Is there foreign matter in the pump?
Temperature of the rolling bearings is too
high :
How high is the actual temperature measured?
How high may it be acc. to the operating manual?
Is the running-in phase already over?
Deficient lubricant?
Overageing / wear?
Leak from the pump :
Are all screws tightened to the correct tightening
torque?
Were the sealing surfaces assembled in a clean
state?
Have approved gaskets been installed?
