8
Trouble-shooting
Pump delivers insufficient flow rate
Motor is overloaded
Excessive pump discharge pressure
Excessive bearing temperature
Leakage at the pump
Excessive leakage at the shaft seal
Vibrations during pump operation
Impermissible rise of temperature inside the pump
Table 26: Trouble-shooting
A B C D E F G H Possible cause
Remedy
15)
X
Pump delivers against an excessively
high discharge pressure.
Re-adjust to duty point.
Check plant for impurities.
Fit a larger impeller.
16)
Increase the speed (turbine, I.C. engine).
X
X X Pump or piping are not completely
vented or primed.
Vent and/or prime.
X
Supply line or impeller clogged.
Remove deposits in the pump and/or piping.
X
Formation of air pockets in the piping.
Modify the piping.
Fit a vent valve.
X
X X Suction head is too high, NPSHavailable
(positive suction head) is too low.
Check/alter liquid level.
Install pump at a lower level.
Fully open shut-off valve in the suction line.
Change suction line, if the friction losses in
the suction line are too high.
Check any strainers installed/suction opening.
Observe permissible speed of pressure fall.
X
Air intake at the shaft seal.
Clean flushing liquid duct, supply external
flushing liquid, if necessary, or increase
flushing liquid pressure.
Replace the shaft seal.
X
Wrong direction of rotation
Interchange two of the phases of the power
supply cable.
X
Speed is too low.
- operation with frequency inverter
- operation without frequency inverter
- Increase voltage/frequency at the frequency
inverter in the permissible range.
- Check the voltage.
X
X
Wear of internal pump parts
Replace worn components by new ones.
X
X
Pump back pressure is lower than
specified in the purchase order.
Re-adjust to duty point.
In the case of persistent overloading, turn
down impeller.
16)
X
Density or viscosity of the fluid pumped
is higher than stated in the purchase
order.
Contact KSB.
X
Wrong shaft seal materials
Change the material combination.
16)
X
X
Gland follower too tight or askew.
Correct.
X X
Speed is too high.
Reduce speed.
16)
X
Tie bolt/gasket defective.
Fit new gasket between volute casing and
discharge cover.
Re-tighten the bolts.
X
Worn shaft seal
Replace the shaft seal.
Check flushing liquid/barrier fluid.
A
B
C
D
E
F
G
H
15)
Pump pressure must be released before attempting to remedy faults on parts which are subjected to pressure.
16)
Contact KSB.
8 Trouble-shooting
Etanorm
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