Document / Project Reference
Orifice Sizing
AS 2360.1.1-1993 · concentric square-edged orifice basis
Single-phase flow only. No flashing. Screening / FEED calculation summary.
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  |  Hazem ElMancy — Orifice Sizing
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PIPING / FLOW MEASUREMENT

Orifice Sizing

Single-phase liquid and gas orifice plate sizing for concentric square-edged meters using differential-pressure flow equations, iterative beta-ratio solving, discharge coefficient, expansibility factor, Reynolds number, permanent pressure loss and velocity validity checks.

AS 2360.1.1-1993Liquid / GasFlange · Corner · D & D/2
All Calculators

Enter orifice design data and run the calculation.

Calculation basis

  • Uses AS 2360.1.1-1993 style Reader-Harris/Gallagher discharge coefficient equation.
  • Solves the circular beta/orifice-diameter equations iteratively until convergence.
  • Supports Liquid and Gas, with expansion factor and sonic check applied to Gas.

Core equations

  • ReD = 4ṁ/(πμD)
  • ε = 1 for liquids; for gas: ε = 1 − (0.41 + 0.35β⁴) ΔP/(kP₁)
  • C = 0.5959 + 0.0312β²·¹ − 0.184β⁸ + 0.0029β²·⁵(10⁶/ReD)^0.75 + tapping terms
  • d = √[ṁ√(1−β⁴)/(ε(π/4)C√(2ΔPρ))]
  • Permanent pressure loss ≈ (1−β¹·⁹)ΔP
  • Fluid must be single phase with no flashing.
  • Pressure input is absolute for upstream pressure and differential for ΔP.
  • Range checks are displayed without suppressing calculation results.
  • Final flow measurement design shall be checked against project metering philosophy, straight-run requirements, plate material, tapping installation and applicable standard edition.