Orifice Plate Calculator

Calculate flow rate, pressure drop, or required orifice bore size for orifice-plate flow measurement, per ISO 5167-2. Discharge coefficient Cd uses the Reader-Harris/Gallagher correlation with corner, flange, or D-D/2 tap configurations. Supports both liquid and gas service (gas adds the expansion factor ε for compressibility).

Inputs: pipe internal diameter, orifice bore diameter (or beta ratio), fluid properties, and any two of {flow rate, ΔP, orifice size}. The calculator solves for the third. Beta ratio guidance: 0.2–0.7 for accurate ISO 5167 application; outside that range a warning is shown.

Related: valve sizing, friction loss, how orifice plates work. For full networks with multiple orifices, build a model in SimuPipe.