# Orifice plate sizing and flow rate calculator

Orifice plate creates pressure drop in a tube and can be used as flow meter or for flow rate reduction as sudden tube diameter reduction limits flow rate on certain value depending on available pressure in front of the orifice.

Orifice plate flow in a tube and sizing calculator can be used for orifice plate sizing or orifice flow rate calculation for given pressure drop. Flow rate through orifice plate calculation is based on energy equation and Bernoulli theorem. Orifice plates are very practical as flow meters in large tube diameters and for dirty fluid when turbines are not applicable.

Measure pressure drop in front and after the orifice plate in a tube and calculate flow rate, orifice tube size, Reynolds number, flow mean velocity, and more with this calculator.

Orifice plate calculator can be used for flow through orifice calculation and orifice sizing for liquids and gases.
Calculator is applicable for subsonic flow and single phase fluid.
Gas is considered as compressible and ideal. For gas flow, pressure ratio
p_{2}/p_{1} must be equal or greater than 0.75.
Calculator is not for pulsating flow.

Limits of use for orifice plates with a corner and D and D/2 tappings:

- d > 12.5 mm
- 50 mm < D < 1000 mm
- 0.1 < β < 0.75
- Re
_{D}> 5000 for 0.1 < β < 0.56 - Re
_{D}> 16000xβ^{2}for β > 0.56

Limits of use for orifice plates with flange tappings:

- d > 12.5 mm
- 50 mm < D < 1000 mm
- 0.1 < β < 0.75
- Re
_{D}> 5000 and Re_{D}> 170xβ^{2}xD

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