KSB WKTR - Trouble-shooting Common Issues

8 Trouble-shooting
Fault Possible cause Remedial action
Usable flow rate < specified
value
Pump delivers against an excessively
high pressure.
Keep opening the valve in the discharge
line until the operating point is re-
adjusted.
Excessive back pressure Fit larger impeller(s).
Contact KSB Service.
Increase the speed of the drive.
Check system for impurities.
Pump or piping are not completely
vented or primed.
Vent and/or prime.
Inlet pipe or impeller(s) clogged/
jammed.
Remove deposits in the pump and/or
piping.
Formation of air pockets in the piping Alter the piping layout.
Fit a vent valve.
NPSH
available
(positive suction head) is
too low.
Adjust the fluid level in the inlet tank.
Completely open the valve in the inlet
pipe.
Change inlet pipe if the friction losses in
the inlet pipe are too high.
Check any strainers installed.
Excessive speed of pressure fall Observe permissible speed of pressure fall.
Excessive suction head Clean the filter element and the inlet pipe.
Correct/alter the fluid level.
Alter the inlet pipe.
Check any strainers installed.
Wrong direction of rotation Interchange two phases of the power
cable.
Speed is too low. Increase the speed.
Increase the voltage.
Contact KSB Service.
Wear of internal pump parts Replace defective parts.
Contact KSB Service.
Motor is running on two phases only. Replace defective fuses.
Check electrical connections.
Pump discharge pressure >
specified value
Speed is too high. Contact KSB Service.
Pressure ps < specified value Damaged measuring instrument Replace the measuring instrument.
Excessive differential pressure in the
filter
Dismantle and clean the filter element.
Valve in the inlet pipe not completely
opened
Open the valve.
Pressure in the inlet tank is too low. Check the inlet tank and/or increase the
pressure.
Pressure pd < specified value Damaged measuring instrument Replace the measuring instrument.
Speed is too low. Check the drive.
Inlet pressure too low Check inlet pressure and inlet tank.
Fluid temperature too low or too high. Increase or reduce the temperature.
Defective minimum flow system Check the minimum flow system.
Shaft seal leakage Defective shaft seal Check and, if required, replace it.
Score marks or roughness on shaft
sleeve (523)
Check shaft sleeve (523) and, if required,
replace it.
Seal cover tightened incorrectly Check.
Pump set alignment Check the coupling; re-align, if required.
8 Trouble-shooting
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WKTR