The minimum internal diameter of a pipe for a required gas flow rate and maximum allowable pressure loss can be calculated as follows:



Figure 46 Find Diameter Calculation – Gas


  1. Select the Find Diameter calculation.
  2. Select or define the Material and Internal Roughness of the pipe.  For more information about working with pipe materials, see: Pipe Material & Diameters
  3. Set the Length and Elevation Change of the pipe.
  4. Add Fittings to the pipe if required.  For more information about working with fittings, see: Fittings & Valves
  5. Select the Fluid in the pipe.  For more information about working with fluid, see: Fluids Database
  6. Enter the Pressure of the fluid at the start of the pipe.
  7. Enter the Flow Rate of the fluid in the pipe. 
  8. Enter the maximum Pressure Loss in the pipe.
  9. Tap Calculate Diameter and the Results panel will slide up.

The length will be reset to 32.80 ft (10 m) if running the trial version of Pipe Flow Wizard.

The Find Diameter Results Panel displays the calculation input data and the results of the Find Diameter calculation.  For more information about the Results Panel, see: Results Panel


The Diameter units can be changed as required.  To change the diameter units for all subsequent calculations, the diameter unit can be specified in Settings > Units.  For more information about setting units, see: Units


To generate and view an Excel or PDF Report of the results, tap the Excel button or PDF button.  For more information about generating reports, see: Creating a Report of the Results


To change the number of decimals the results are displayed to, tap the Results Decimals button in the Results Menu Bar.  For more information, see: Results Menu Bar


To copy the calculation data to one or more other calculations, tap the Copy button and select the required calculation(s).



Figure 47 Find Diameter Results – Gas


To close the Results Panel, tap the Close button in the Navigation Bar or the Close Results   button at the bottom.