Cyclic-Life Calculator

This calculator determines cyclic life of PVC pressure pipe subjected to recurring surge pressures. Its primary use is for sewer force mains. Water transmission and distribution systems typically do not have sufficient frequency and magnitude of surge pressures to require consideration of cyclic life.

The calculator is based on the Force Main Design Guide for PVC Pipe, which can be consulted for explanations of the concepts and equations used.

For a step-by-step process on how to use this calculator, see Calculator Instructions.

The formulas used to calculate cyclic life are as follows:

Where :

σamp = amplitude of pipe wall hoop stress from cyclic pressures, psi

Prs(max) = maximum pipe pressure from a recurring surge event, psi

Prs(min) = minimum pipe pressure from a recurring surge event, psi

DR = pipe dimension ratio, dimensionless = OD/t

Where :

N = number of cycles to failure

Where :

n = number of cycles per year from pump operations

Recurring Surge Event

Looks good!
Enter value greater than or equal to 0
(only two decimal places are allowed)
Looks good!
Enter value greater than or equal to -14.7
(only two decimal places are allowed)
Looks good!
Enter value greater than or equal to 0
(only two decimal places are allowed)

Disclaimers

  • This calculator performs only one function: determination of cyclic life based on recurring surge pressures in PVC pressure pipes.
  • The designer is responsible for the proper use of this program for all projects.
  • PVCPA does not recommend use of online calculators from other organizations for design of PVC pipe.

This calculator was developed based on research performed by Steven Folkman, Ph.D., Utah State University, the results of which were published in the proceedings of ASCE Pipelines 2020.

If you have questions, click here to contact a PVC Pipe Association Regional Engineer.