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Liquid Pipeline Vent

Calculate single phase liquid flow rate through a constant diameter vent.

The vent entry is assumed to be a pressure vessel or piping at stagnation pressure (valid when the pipe or vessel diameter is much greater than the vent diameter). Vent flowrate is calculated from the vent pressure loss factor.

`fld = fL/D + K `

where :

fld = pressure loss factor
f = Darcy friction factor
L = pipe length
D = pipe inside diameter
K = sum of fitting friction factors

Minor losses should include the vent entry, vent exit, valves and bends etc. The discharge coefficient can be used to factor the flow rate, depending on the design requirements.

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Links : ±
CALCULATOR : Single Phase Liquid Pipeline Pressure Loss General [FREE]   ±

Calculate general liquid pipeline outlet pressure from flow rate and diameter using the Moody diagram.

The Moody diagram combines the Hagen-Poiseuille laminar flow equation with the Colebrook White turbulent flow equation (either the original Colebrook White equation or the modified Colebrook White equation).

Tool Input

  • fdtype : Darcy Friction Factor Type
    • fdu : User Defined Darcy Friction Factor
  • ρ : Fluid Density
  • ID : Pipe Inside Diameter
  • r : Pipe Inside Surface Roughness
  • L : Pipe Length
  • K : Minor Loss K Factor
  • zi : Inlet Elevation Relative To Datum
  • zo : Outlet Elevation Relative To Datum
  • Pi : Inlet Pressure
  • μ : Dynamic Viscosity
  • Q : Volume Flowrate

Tool Output

  • ΔP : Friction Pressure Loss
  • M : Mass Flowrate
  • Po : Outlet Pressure
  • Re : Reynolds Number
  • V : Fluid Velocity
  • cvg : Convergence Factor (≅ 1)
  • fd : Darcy Friction Factor
  • rr : Surface Roughness Ratio
CALCULATOR : Single Phase Liquid Pipeline Vent [FREE]   ±

Calculate single phase liquid flow rate and pressure drop through a constant diameter vent.

Minor losses should include the vent entry, valves, bends etc, and the vent exit. The fluid dynamic pressure is not included in the calculation. The Darcy friction factor can be calculated using either the original Colebrook White equation, the modified Colebrook White equation, the von Karman rough pipe equation, or can be user defined. The discharge coefficient can be used to factor the mass flow rate.

Tool Input

  • schdtype : Vent Schedule Type
  • diamtype : Vent Diameter Type
    • ODu : User Defined Outside Diameter
    • IDu : User Defined Inside Diameter
  • wtntype : Wall Thickness Type
    • tnu : User Defined Wall Thickness
  • visctype : Viscosity Type
    • μu : User Defined Dynamic Viscosity
    • νu : User Defined Kinematic Viscosity
  • rrtype : Vent Internal Roughness Type
    • ru : User Defined Surface Roughness
    • rru : User Defined Relative Roughness
  • fdtype : Darcy Friction Factor Type
    • fdu : User Defined Darcy Friction Factor
  • cdtype : Discharge Coefficient Type
    • Cdu : User Defined Discharge Coefficient
  • ρ : Fluid Density
  • L : Vent Length
  • zi : Inlet Elevation Relative To Datum
  • zo : Outlet Elevation Relative To Datum
  • Pi : Inlet Pressure
  • Po : Outlet Pressure
  • K : Minor Loss K Factor

Tool Output

  • ΔP : Friction Pressure Loss
  • μ : Dynamic Viscosity
  • AX : Vent Cross Section Area
  • Cd : Discharge Coefficient (≤ 1)
  • ID : Inside Diameter
  • M : Mass Flowrate
  • Q : Volume Flowrate
  • Re : Reynolds Number
  • V : Fluid Velocity
  • cvg : Convergence Factor (≥ 1)
  • fd : Darcy Friction Factor
  • fdL/ID* : Pressure Loss Factor (Including K)
  • rr : Surface Roughness Ratio
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