Calculations
Recommendations
Circular weirAtmospheric pressure given altitudeAir specific massDynamic viscosity of atmospheric airEstimation of the required NPSH, using the Thoma factorAvailable NPSH calculation
Input data
Temperature
Flow
Diameter (Ds)
Diameter (Db)
Length (L1)
Length (L2)
Level (EL.s)
Level (EL.b)
Roughness
Output data
NPSH
Description
Calculates the available NPSH (Net Positive Suction Head) of a pump. Given the water temperature, flow rate, suction pipe characteristics, and the elevations of the sump water level and the impeller axis, this calculation determines the available NPSH.
NPSH
Input and output parameters table:
Parameter | Standard Units | Description |
|---|---|---|
Temperature ($T$) | °C | Water temperature |
Flow ($Q$) | L/s | Water flow rate |
Diameter ($D_s$) | mm | Suction pipe diameter |
Diameter ($D_b$) | mm | Discharge pipe diameter |
Length ($L_1$) | m | Suction pipe length |
Length ($L_2$) | m | Discharge pipe length |
Level ($EL_s$) | m | Sump water level |
Level ($EL_b$) | m | Impeller axis level |
Roughness ($k$) | mm | Pipe roughness |
Available NPSH | m | Calculated available NPSH |
References
- VIANNA, Marcos Rocha. Produção, Reservação e Distribuição de Água. e-book. Belo Horizonte: Bloom, 2021.