Pipeng Toolbox : Pump Cavitation Calculators Blank User
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Pump Cavitation And NPSH

Calculate pump cavitation number (Ca), nett positive suction pressure (NPSP), and suction specific speed (Nss).

`Nss = n* Q*^1/2 (ρ/NPSP*)^3/4 `
`NPSP* = Ps + 1/2 ρ V^2 - Pv = Ps + Pd - Pv = Pg - Pv `
`Ca = (Ps - Pv) / Pd `

where :

Nss = pump suction specific speed at BEP `
`NPSP* = nett positive suction pressure at BEP `
`Ca = cavitation number `
`n* = pump rotational speed at BEP `
`Q* = flowrate at BEP `
`Ps = static pressure at inlet `
`Pg = stagnation pressure at inlet `
`Pd = dynamic pressure at inlet `
`Pv = vapour pressure `
`V = fluid velocity at inlet `
`ρ = fluid density

The pump suction specific speed and nett positive suction pressure are calculated at the best efficiency point (BEP), the point on the pump curve with the greatest efficiency. The pump suction specific speed, nett positive suction pressure and cavitation number can be used to determine the onset of cavitation. The minimum recommended values are dependent on the pump geometry and operating conditions, and should be obtained from the manufacturer.

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

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Links : ±
CALCULATOR : Pump Delta Pressure And Head Conversion [FREE]   ±

Convert fluid head and pressure.

Fluid head can be calculated from pressure (or vice versa) by

`H = P / (ρ g) `
`P = ρ g H `

where :

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

Tool Input

  • hptype : Head Or Pressure Type
    • Pu : User Defined Pressure
    • Hu : User Defined Head
  • ρ : Fluid Density

Tool Output

  • H : Head
  • P : Pressure
CALCULATOR : Pump Static Dynamic And Stagnation Pressure And Head Conversion [FREE]   ±

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
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