This calculator is intended for the calculation of pressure drop, flow and pipeline dimensions in distribution gas pipelines.

The calculator enables the calculation of natural gas flow by treating it as an incompressible or as a compressible fluid.

In addition to the calculation of the pressure drop due to friction, the calculator also allows the calculation of local resistances in the form of valves or fittings.

The calculation is based on the application of isothermal flow equations, that is, the calculator considers that the gas temperature is the same at the beginning and at the end of the pipeline.

The calculator shows the flow rates at standard and actual conditions, i.e. current pressures and temperatures. The standard conditions are:

- Pressure p = 101325 Pa (14.7 psi), and
- Temperature 15°C (59°F) for metric units and 60°F for imperial units.

The calculator also shows the actual values of the flow rate at the beginning and end of the pipeline.

The calculator is not intended for calculations where there is a sudden change in pressure or temperature, since such conditions imply adiabatic changes of state.