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CTP Mechanically Sealed Plastic Centrifugal Pump Troubleshooting

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    Maintenance

    The CTP range pumps have been designed and tested to run for 5000 hours in ideal working conditions. Please note that it is a conservative figure since the actual duty point of your pump can substantially modify this value. Additional factors such as intermittent operation, type of pumped liquid and installation in the plant may affect the life of components that are subject to wear. In any case, Tapflo advises to service pumps every year, even when used in ideal operating conditions.

    Periodically check the suction and discharge conditions and motor according to the instructions provided by the motor manufacturer.

    Overheating of MotorInsufficient CapacityNo Pressure in the dischargeIrregular CapacityNoise & VibrationThe pump gets CloggedOverheating of the PumpAbnormal WearLeak in the Mechanical SealPossible ReasonSolution
     X X     Motor running in the wrong directionInvert the direction of rotation
     XXXX    Insufficient Suction Head (NPSHa)Increase NPSHa by:
    –  Raise the Fluid Level at the fluid source
    –  Lower the pump
    –  Increase the Pressure in the Suction Tank
    –  Reduce Vapour Pressure
    –  Increase the ø of the Suction Pipework
    –  Make the Suction Pipework shorter and more direct
      X      Pump/pipe is cloggedClean Pump and Pipework & introduce Strainer / Filter
     X XX  X CavitationIncrease NPSHa
    Bring the pump “on curve” by use of a regulation valve on the discharge of the pump
    Reduce the temperature of the liquid
    Clean any filters or strainers
    Ensure there are no air pockets in the pipework
     X XX  X The pump is sucking airMake sure all the connections leading to the pump are tight.
      XXX    Discharge Pressure too highReduce the head by increasing the pipe ø and/or reduce the number of valves and bends
     X  X    Flow Rate is too highReduce the Flow Rate by:

    –  Partially close the discharge valve
    –  Reduce the impeller ø
    –  Reduce the speed of the pump

     X  XXXX Liquid Temperature is too highCool the liquid or introduce a Thermosiphon
            XBroken or Worn Mechanical SealReplace the Seal
            XWrong material of O-RingsMount O-Rings in suitable materials (contact us)
    X   XXX  The Impeller scratches on the pump housingReduce the temperature of the fluid and/or suction pressure.
    Adjust the clearance between the impeller and the housing.
        X  X Too much load on the pipeConnect the pipework independently of the pump using expansion joints/bellows
        XXXX Foreign Objects in the liquidInstall a suitably sized strainer/filter in the suction side of the pump.
            XSpring Tension in the Mechanical Seal too lowAdjust, as detailed in the manual
      X      Shut Off Valve Closed or Obstruction on the Suction SideCheck & remedy
     X       Discharge Pressure too LowIncrease the pressure generated by the pump by installing a larger impeller
    Review the discharge pipework to assess whether it can be made any more direct or shorter.
         XX  The pump is not filled with liquidFill the pump with liquid
    XX  X    Liquid Parameters are different from those calculated with when selecting the pumpCheck the liquid parameters against those supplied.
    Verify selection.
    Review pump suitability and change if necessary.
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