ToolnozaENGINEERING TOOL
Water Pump NPSH Calculator
Calculate available pump NPSH from absolute pressure, vapor pressure, elevation and suction loss; compare with required NPSH.
Water Pump NPSH Calculator
FREE ONLINE TOOLSTEP BY STEP
How to use water pump npsh calculator
- Check the input units and assumptions.
- Review the result and example.
IN PRACTICE
Example
101.325 kPa surface, 2.34 kPa vapor, 998 kg/m³, elevation +2 m, loss 1 m: NPSHa ≈ 11.114 m.
GOOD TO KNOW
Which formula and assumptions are used?
NPSHa = (Psurface,abs − Pvapor,abs) / (ρg) + zsurface − zpump − hL; margin = NPSHa − NPSHr. Reservoir surface velocity assumed negligible. Pressures are absolute, not gauge. Elevation is positive when water surface is above pump. Enter vapor pressure for actual temperature, NPSHr at actual duty and a manufacturer-approved margin; result does not certify cavitation-free operation.