Technical Blog

Welcome to John’s Blog. Answers to frequently asked questions are periodically posted here. The objective is to share information about PVC pipe with readers as well as with utilities, design engineers and pipe installers. The blog provides the latest information on PVC pipe design, installation, and application for water and wastewater infrastructure projects.

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John Houle: Senior Technical Consultant, PVC Pipe Industry

John Houle holds a Master’s Degree in Civil Engineering from the University of Missouri and an MBA from the University of Oregon. He has more than 25 years of experience in the plastic pipe industry in applications engineering, market development, forensic analysis, technical writing, and standards development.

Correctly Assembled Gasketed PVC Pipe: Part Two

Posted By John Houle on Apr 4, 2013

Last week’s blog entry described the importance of correctly installing PVC pipe spigots to the insertion line. This week we will look at what happens inside the pipe when the joint is assembled correctly.


Expansion Gaps: Important for PVC Pipe Joint Design

With correct installation, there is a horizontal gap inside the joint between the end of the spigot and the shoulder of the bell. This gap is the subject of the attached technical brief. Click here to read. The gap occurs in both pressure and non-pressure pipe, but is observable only during video inspection of gravity-flow sanitary sewer pipe.

The gap is necessary to provide room for thermal expansion of the pipe and to allow for angular joint deflection that accommodates any ground movement that occurs. The gap is an integral feature of the joint design and does not affect the joint’s water-tightness or its hydraulic characteristics.