NPSH Calculator

Enter value and click on calculate. Result will be displayed.

NPSHa = (Pa-Pv+Pn) / P
NPSHa = NPSH Available
Pa = Atmospheric Pressure
Pv = Vapor Pressure
Pn = Gage Pressure at the Pump Suction
p =Density

Atmospheric Pressure (Pa):
Vapor Pressure (Pv):
Gage Pressure at the Pump Suction (Pn):
Density:
Kg / m3
NPSH Available:

NPSH (Net Positive Suction Head) is a crucial parameter used in fluid dynamics, especially in pump systems, to ensure that a pump operates without cavitation. Cavitation can damage the pump, leading to inefficiency and even failure.

What is NPSH?

NPSH refers to the pressure difference between the suction pressure at the pump inlet and the vapor pressure of the fluid. It ensures that the liquid entering the pump is above its vapor pressure, preventing the formation of vapor bubbles, which causes cavitation.

Why is NPSH Important?

  • Prevents Cavitation: Cavitation occurs when the local pressure drops below the vapor pressure of the fluid, causing vapor bubbles that can collapse and damage the pump.
  • Ensures Efficient Pumping: Proper NPSH ensures the pump operates at peak efficiency without cavitation or damage.

How NPSH is Calculated?

To calculate NPSH, the formula is:

NPSH=Htotal−Hvapor

Where:

  • is the total suction head (pressure head + elevation head).
  • is the vapor pressure head of the fluid at the given temperature.

When to Use NPSH Calculators?

  • System Design: When designing a new pump system to ensure cavitation doesn't occur.
  • Troubleshooting: To identify if a pump is operating under conditions where cavitation could develop.

NPSH calculators help determine if the suction conditions are sufficient for proper pump operation by comparing the available NPSH with the required NPSH (NPSHr), which is provided by the pump manufacturer.