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.

Safety Considerations for Air-Testing of PVC Sewer Pipes

Posted By John Houle on Sep 29, 2016

Occasionally I hear a report about safety issues with air-testing of sewer pipes. The story usually starts with “An end-plug let go.” There was a sudden whoosh of air out of the manhole that had potential consequences for nearby personnel.

The story continues: “I think the pressure was too high” or “I guess the plug wasn’t installed properly.”

The danger arises from the assumption that “low pressure” means “no pressure.”

The truth is that low pressure can equate to high thrust forces on the plugs, especially for large-diameter pipes. For example, pressure of 5 psi in a 48-inch pipe creates about 9,000 pounds of thrust on the end-plug; and 9 psi in a 60-inch pipe generates almost 24,000 pounds of thrust.

There are a few simple precautions to take to protect the safety of jobsite personnel. To find out more click here for my Tech Brief titled “Safety Considerations for Air-Testing of PVC Sewer Pipes.”