scope:

This MOP covers the thickness design of flexible liners to be installed in a gravity-flow sewer or culvert pipe; the host pipe can be rigid or flexible and be circular or noncircular; the installation method is trenchless and yields close-fit lining, for example, cured-in-place lining or fold-and-form lining.

Purpose

The purpose of this Manual of Practice (MOP) is to provide guidance to the consulting engineers tasked with designing flexible close-fit liners for the renewal of existing gravity pipe applications in a form that is readily usable. Upon reading the manual, the consulting engineers should be able to understand and apply design procedures detailed in the manual to calculate the required liner thickness in deteriorated pipes for which these procedures have been developed and are applicable. In most cases, the closed-form solution is already available and where that is not the case, the finite-element analysis is recommended; in some cases, different rehabilitation options should be considered. The design guidance will no doubt need to be updated as the understanding for liners in pressure piping applications is developed and can be implemented herein.

In the meantime, the task group charged with this MOP's production advises the engineering community that the pressure pipe design guidance also contained in the ASTM standard F1216 has been found to be quite lacking and should not be employed as presented therein in the design of liners in pressure pipe applications.