12
6.Operating problems
2015/01
6.
Operating problems
The attached table lists solutions to problems that may arise while operating the pump. It is assumed that the pump
has been properly installed and that is has been selected correctly for the specific application.
Contact INOXPA if technical assistance is required.
Motor overload
ò
The pump flow or pressure is insufficient.
ò
There is no pressure on the discharge side.
ò
Irregular discharge flow rate / pressure.
ò
Noise and vibrations.
ò
The pump gets clogged.
ò
Pump overheated.
ò
Abnormal wear.
ò
Leak through the mechanical seal.
ò
PROBABLE CAUSES
SOLUTIONS
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Wrong direction of rotation.
Reverse the direction of rotation .
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Insufficient NPSH
Raise the suction tank.
Lower the pump.
Reduce the vapour pressure.
Widen the diameter of the suction pipe.
Shorten and simplify the suction line.
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Pump not purged
Purge or fill.
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•
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Cavitation.
Increase the suction pressure.
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The pump sucks in air.
Check the suction line and all of its
connections.
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Suction pipe obstructed
Check the suction line and the filters, if
available.
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Discharge pressure too high
If necessary, reduce the pressure losses,
for example, by increasing the pipe
diameter.
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Flow rate too high
Reduce the flow by means of a
diaphragm.
Partially close the discharge valve.
Trim the impeller.
Decrease speed.
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Viscosity of the liquid too high.
Reduce the viscosity, for example, by
heating the liquid.
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Liquid temperature is too high
Decrease the temperature by cooling the
liquid.
•
Mechanical seal worn or damaged.
Replace the seal.
•
Inadequate O-rings for the liquid.
Install the correct O-rings after
consulting the supplier.
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The impeller scrapes
Lower the temperature.
Reduce the suction pressure.
Adjust the impeller/cover play.
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Tension in the lines.
Connect the pipes to the pump without
tension.
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Foreign matter in the liquid.
Install a filter in the suction pipe.
•
Mechanical seal spring tension is too
low.
Adjust as indicated in this manual.
