Pump Speed Calculators - Pipeng Toolbox

Ns = pump specific speed
n = pump rotational speed
Q = flow rate at BEP
ρ = fluid density
ΔP = delta pressure at BEP
ΔH = delta head at BEP
g = gravity constant
BEP = best efficiency point

The pump specific speed can be used to determine the type of pump which should be used (multi stage, centrifugal, mixed flow or axial). The pump size and speed can then be determined from the pump coefficients using the affinity or similarity laws. Usually, a known pump is scaled to operate at the BEP with the required design flow rate and delta pressure.

PLEASE NOTE : The pump calculators are currently being updated. Apologies for any inconvenience.

Convert pump pressure and pump head (static and stagnation pressure / head).

Pump head can be calculated from pump pressure by

`H = (P) / (ρ g) `

where :

H = head
P = pressure
ρ = fluid density
g = gravity constant

The stagnation pressure is calculated by

`Pg = Ps + Pd `
`Pd = 1/2 ρ V^2 `
`V = (4 Q) / (pi D^2) `

where :

Ps = static pressure
Pg = stagnation pressure
Pd = dynamic pressure
V = fluid velocity
Q = volume flowrate
D = inside diameter

Tool Input

schdtype : Pipe Schedule Type
diamtype : Pipe Diameter Type
- ODu : User Defined Outside Diameter
- IDu : User Defined Inside Diameter
wtntype : Wall Thickness Type
- tnu : User Defined Wall Thickness
voltype : Fluid Flowrate Type
- Qu : User Defined Volume Flow Rate
- Mu : User Defined Mass Flow Rate
- Vu : User Defined Fluid Velocity
presstype : Pressure Type
- Psu : User Defined Static Pressure
- Pgu : User Defined Stagnation Pressure
- Hsu : User Defined Static Head
- Hgu : User Defined Stagnation Head
ρ : Fluid Density

Tool Output

Hd : Dynamic Head
Hg : Stagnation Head
Hs : Static Head
ID : Inside Diameter
M : Liquid Mass Flowrate
Pd : Dynamic Pressure
Pg : Stagnation Pressure
Ps : Static Pressure
Q : Liquid Volume Flowrate
V : Fluid Velocity

Pump Specific Speed

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Tool Input

Tool Output