Advanced science.  Applied technology.


Orifice Flow Meter Calibration

Orifice meters measure flow rates using differential pressure created when a fluid passes through an orifice plate. The flow calculations use a form of the Bernoulli equation with an empirical discharge coefficient. Orifice flow meter calibration helps reduce uncertainty in the discharge coefficient from 0.5% to 0.25%.

Orifice meters are normally built to specification from standards such as API 14.3, AGA 3, and ISO 5167. Southwest Research Institute performs flow calibrations to lower uncertainty by matching the Reynolds number to the final application. Improved flow measurement improves accuracy for computing plant efficiency, system balances and end-user consumption.

Orifice Plate Calibration & Flow Meter Services

Flow calibration of an orifice flange fitting and plate

Flow calibration of an orifice flange fitting and plate over the application Reynolds number range.

Flow calibrations and tests at SwRI typically require one day for setup and checkout and half a day for testing. Clients can witness tests in person or monitor remotely. Reports can be generated that reference either API 14.3/AGA-3, ASME PTC 19.5, or any other commonly used orifice meter standard.

ISO 5167 Differential Flow Meter Services

In addition to orifice plates and meters, we calibrate and test other ISO 5167 differential flow meters:

  • Cone meters
  • Averaging pitot meters, anemometers  and other velocity flow meters
  • Subsonic venturis (ASME MFC-7M and ISO 9300)
  • Wedge flow meters

Orifice Flow Meter Troubleshooting & Research

SwRI has been a leader in orifice meter diagnostics for many years as evidenced by the development of the patented square root error indicator. Pulsation detection and assessment is just one of the services that we can provide to improve your measurement. SwRI can provide field audits of meter stations that include orifice meters and suggest operational and configuration changes to improve your measurement.

Many improvements to the orifice meter standards were verified by testing at SwRI's Metering Research Facility. Visit Flow Measurement Research Programs to learn how SwRI has is helping to advance technology for orifice flow meters and other flow measurement systems.

Flow Measurement & Metering Research


Or call Adam Hawley at +1 210 522 3427.