Friction loss for a compressible fluid, such as a gas, needs to account for the change in density, as the gas moves along the pipe and loss of pressure occurs. When using the compressible flow calculation engine Pipe Flow Wizard can be set to use one of the following compressible flow equations: 


  • General Fundamental Isothermal Flow Equation
  • Complete Isothermal Flow Equation
  • AGA Isothermal Flow Equation
  • Weymouth Isothermal Flow Equation
  • Panhandle A Isothermal Flow Equation
  • Panhandle B Isothermal Flow Equation
  • IGT Isothermal Flow Equation


The formula for each of the above equations is detailed in a separate PDF document named ‘Compressible Flow Equations’. This PDF is available from the ‘Verification’ menu inside the Pipe Flow Wizard software.