There are so many reasons that make centrifugal pumps one of the widely used water pumps across the globe. But, that does not make these pumps invincible to wear and tear. These pumps also come across various issues with extensive functioning. But, timely troubleshooting can help in maintaining their efficient functioning. Let us discuss varied things that should be considered while you troubleshoot different issues of pumps –

  • Majority of the pumps are oversized keeping in mind the safety elements that were considered during the sizing of the pump.
  • Centrifugal pump starts its functioning as and when the curve of the pump cut across the system curve.
  • Pumping the difference between the discharge and the suction heads is one of the key things that makes these pumps unique as compared to others.
  • If you somehow find that pump is not able to fulfill the system curve requirements then, as per the experts, the pump might be facing some issue, more specifically, around the discharge system.
  • As per the nature of the pump, it usually pumps the mixture of both capacity and the head. And if these two numbers gets multiplied then it has to be ensured that they should remain constant. It can also be said that when there is an increase of the head the capacity should come down. Similarly, the capacity has to increase with the decrease of the head.

Issues towards the pump’s suction side -

  • There are chances that the foot valve has stuck.
  • Between the source tank and the pump suction, extra piping has been used.
  • Instead of a gate valve, a globe valve has been used.
  • There might be clogging of the strainer or the filter.
  • An elbow is quite close to the pump suction.
  • The tank float has got stuck. This leads to the increase in the tank level which is actually not there.

Issues in the pump -

  • The impeller has broken.
  • The impeller has got blocked.
  • The shaft is functioning backwards.
  • The diameter of the impeller is not apt.
  • The speed of the impeller is quite slow. Make sure you have cross-checked the frequency and the voltage.
  • The impeller, used for cutwater clearance, is quite big.
  • The width of the impeller is quite narrow.
  • The installation of the impeller has been done backwards.
  • Air is entering via packing in the pump suction.
  • The pump was not properly primed before startup.
  • A wrongly sized pump has been selected.
  • Instead of a volute design, a concentric casing is actually needed.
  • The size of the wear ring clearance is quite big.
  • A wear ring is not actually there.
  • A variable speed motor is being put into use in order to produce a flat curve. Make sure that you are aware of the fact that with the variation of the speed, there is a difference in both the capacity and head.

So, when the pump is not producing sufficient capacity, make sure that you make the best of the above discussed information.