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Centrifugal pumps.

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  • Centrifugal pumps.

    What is NPSH (Net positive suction head)?

  • #2
    NPSH is an indicator of cavitation. It is a measure that lets us know how much a fluid is close to cavitation and boiling. Centrifugal pumps are very vulnerable to cavitation and it can lead to the damage of the impeller. NPSH keeps us informed about whether the fluid is reaching the cavitation level. There are two levels of NPSH-- the available level, designated as NPSHA and the required level which is NPSHR. If the available level is less than the required level, cavitation will occur. Apart from the centrifugal pumps, NPSH is also considered for turbines as that also involves a hydraulic circuit.


    • #3
      It is the minimum pressure/energy from the fluid that the pump require to operate efficiently the NPSH available must always be greater than the NPSH required by the pump


      • #4
        Second floor, oceanhub has the right and complete answer.


        • #5
          Net Positive Suction Head (NPSH)
          NPSH can be defined as two parts:
          NPSH Available (NPSH
          A): The absolute pressure at the suction port of the pump.
          NPSH Required (NPSHR): The minimum pressure required at the suction port of the pump to keep the pump from cavitating.
          NPSHA is a function of your system and must be calculated, whereas NPSHR is a function of the pump and must be provided by the pump manufacturer. NPSHA MUST be greater than NPSHR for the pump system to operate without cavitating. Put another way, you must have more suction side pressure available than the pump requires.

          Please check more at below.