NCPI Toolbox

With over 100-years of research, publication and education, NCPI has created a library of extensive tools you can trust.

NCPI Toolbox is a group of three NCPI-developed programs that provide engineers tools for calculating Trench Load, Hydraulic Flow and Leastcost. The programs contained in the Toolbox are designed to solve many of the design problems associated with sanitary sewer lines. For additional information or clarification, please contact your NCPI field representative or a member company.

Trench Load

Trench Load is a design program incorporating Marston’s equations for soil loads on rigid conduits and the latest ASTM requirements.

  • See the Safety Factor associated with each bedding class for your project
  • Include Live Load calculations and specify the impact factor using AASHTO standards
  • Specify which standard should be applied (ASTM C700, Greenbook Extra Strength or Greenbook High Strength)
  • And much more …


Hyflow utilizes Manning’s open channel flow equations to determine hydraulic solutions.

By entering the desired flow rate and slope, the recommended pipe diameter with depth of flow is instantly displayed.


Leastcost uses historic inflation and interest rates, together with life cycle analysis, to provide an equitable cost comparison between material options over the service life of an installation.

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