Oil and gas calculation library

Flow-Xpert provides the typical calculations used in custody transfer measurement.

  • Proven oil and gas calculations
  • Free iOS and Android app
  • Flow computer validation

Flow-Xpert - Calculations

Certified flow and hydrocarbon property calculations for FREE !!!

Flow-Xpert is based on the Flow-X flow computer calculation library that is used in numerous installations and is verified by many test laboratories and oil and gas companies. It provides all the typical fluid and hydrocarbon property calculations used for custody measurement (AGA, API, ASTM, GERG, GPA, ISO etc.).

The free iOS and Android apps can be used to verify single calculations. The Excel add-in allows you to build your own tool to verify and audit flow computers, volume correctors, EFM's and RTUS. The DLL interface allows for the integration of proven oil and gas calculations in any automation system.

Flow-Xpert supports both the metric and US Customary versions of the AGA and API implementations.


  • Both metric and US customary units
  • GERG-2008
  • All API MPMS Ch. 11 table editions
  • Historical API tables (1952)
  • Automatic unit conversions
  • Excel add-in


  • What oil and gas products are supported with Flow-Xpert?

    Flow-Xpert supports the typical products, for which flow computers are used:

    - Natural gas;
    - Crude oil and refined oil products;
    - LPG (Liquified Petrol Gas);
    - NGL (Natural Gas Liquids);
    - LNG (Liquified Natural Gas);
    - Propylene, Ethylene, Butadiene;
    - Steam;
    - Water;
    - Carbon Dioxide.

  • Why isn't the standard volume flow calculation of the AGA standard included?

    The AGA standards for flow meters (AGA-3 for orifice, AGA-7 for turbine, AGA-9 for ultrasonic and AGA-11 for Coriolis) define the calculation of the basic volume flow rate, based on the AGA-8 standard, to obtain the gas compressibility and density.
    Flow-Xpert only incorporates the calculation of the primary flow rate value; it does not intend to be a full implementation of any standard. The Excel add-in and the DLL allow for custom applications to tie individual calculations together into a full implementation of the standard.

  • Where can I download the app?

    The free-of-charge Flow-Xpert app can be downloaded from the iTunes and GooglePlay stores.
    Search for 'FlowXpert' (without the dash).

Interested? Contact our sales department. Call +31 40 23 69 445 or E-mail E-mail