A Pipe Size library contains the acceptable pipe sizes and slope limits that will be used by the pipe autosize calculations. Libraries can be saved as .XPPIPX files so that they can be shared/reused.

By selecting this option you will be able to edit / create a pipe size library. Simply enter the required pipe diameters in the spreadsheet. The values must be in ascending order of size and note that if the largest pipe in the file is not big enough for the flow then the program will continue based on the Additional Increment specified (75 mm / 3 inches by default) until sufficient capacity is reached.

Every Pipe Size entered may have values added for the Minimum and Maximum slope values. These values can be left at 0 to allow the engine to use the full range of valid slopes. If specified, any pipes of that diameter will always be constrained by the given slope limits. If the sized pipes end up above the last specified Diameter, no slope limits will be applied.


Fixed Slopes can be achieved by entering a Min Slope = Max Slope.

If the Pipe Sizing Min. Slope is enabled, it will be used only if the Pipe Size Library does not have a value specified. This allows a global setting to be in place and overridden only by specific pipe sizes.

The Default button loads the details of the Standard pipe size library based on the short length Units Translation setting.

Workflow - What's next...?

Inflows connect to either  Junctions or  Stormwater controls  via  Inlets . Specify an  Pipe Size Library on these objects then choose to connect to another Junction or Stormwater Control.