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Orifice plate sizing calculator

find flow rate for measured pressure difference

Order orifice plate flowmeter

orifice plate, Venturi tube or nozzle flow.

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Orifice plates are used for measuring flowrate of fluids flowing through the closed pipes. Orifice meter is inserted in the pipeline and it causes drop of fluid static pressure. Flowrate measuring through the pipeline is done indirectly, calculating flowrate from the measured pressure loss in front and after the orifice plate. Pressure loss through the orifice is directly proportional to the fluid flowrate and that relation is used for conversion from the measured pressure drop to the value of the fluid flowrate.

This calculator can be used for orifice meter diameters calculation for given values of the flowrate and measured pressure in front and after the orifice.

Calculator can do flow rate calculation through orifice meter for given orifice diameters and measured pressure loss.

Orifice meter calculator is applicable for liquids and perfect gases, subsonic flow of single phase fluid. It is not applicable for pulsating flow.

Computation is according to ISO 5167-2 and all applied formulas and results can be considered correct and reliable only if the conditions from the standard are fulfilled. Some of the conditions are given below.

For perfect gas flow, pressure loss in the orifice meter must be higher than 0.75.

Orifice meters which have corner pressure tappings or D and D/2 pressure tappings must meet following conditions:

  1. d > 12.5 mm
  2. 50 mm < D < 1000 mm
  3. 0.1 < β < 0.75
  4. ReD > 5000 for 0.1 < β < 0.56
  5. ReD > 16000xβ2 for β > 0.56

Orifice meters which have flange pressure tappings must meet following conditions:

  1. d > 12.5 mm
  2. 50 mm < D < 1000 mm
  3. 0.1 < β < 0.75
  4. ReD > 5000 and ReD > 170xβ2xD

Read more about standard used in this calculator - ISO 5167-2