Pump VFD Design Speed Calculators

ΔP1 and ΔP2 = the delta pressure for pump 1 and 2
Q1 and Q2 = the flowrate for pump 1 and 2
n1 and n2 = the rotation speed for pump 1 and 2
ρ1 and ρ2 = the fluid density for pump 1 and 2

The pump curve is calculated using a three term quadratic curve:

`ΔP = ΔPo (1 - A Q - B Q^2 ) `

where :

ΔPo = the shut in delta pressure
A and B are constants

The design pump speed can be calculated by solving the quadratic equation for the design delta pressure and flowrate. For fluids with a kinematic viscosity ν > 20 cSt, the viscous calculation is recommended.

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 Variable Frequency Drive (VFD) Design Speed

Change Module :

Tool Input

Tool Output