all the suction line valves are kept fully opened. In addition, inspect
the suction pipe to check for poor fluid flow or great flow resistance.
Clean well the strainer if provided.
5. Reverse rotational direction.
Interchange the wiring connection to the motor terminal. Should the
pump rotate reversely, check the packing sleeve and retighten it as
necessary.
6. No. of revolutions ( rotational speed slower
than the specified ).
Check voltage and frequency.
7. Wear of pump component.
Overhaul the pump to check the wear degree of parts and replace
worn parts with new one(s) if necessary.
5. 2. Overload of driver ( electric motor )
Possible Cause
Remedy / Corrective Action
1. Pump back pressure lower than the
specified.
Clean the discharge sluice valve up to the specified pressure point.
2. Handling of fluid with greater specific gravity
or at lower temperature than that specified
in specification.
Where it is not impossible to keep specific gravity and temperature
indicated in the specification, but the discharge capacity to the
allowable rate of the driver. When good effect cannot be obtained
even after that, be in touch with our Technical Departement.
5. 3. Excessive discharge pressure
Possible Cause
Remedy / Corrective Action
1. Excessive rotational speed.
Check the rotational speed ( no. of revolutions ) carefully. In the
event of failure in speed down, be in touch with our Technical
Departement for further instruction. In such case, it will be necessary
to either reduce the number of stages or to cut the impeller diameter.
2. Too low discharge temperature or too large
specific gravity.
When the pump running in such conditions is required, be in touch
with our Technical Departement for further instruction.
3. Too high force head.
Investigate carefully the forced head. If the change of this pipeline is
impossible, be in touch with our Technical Departement.
