Released on June 30, 2010

In a study of the effects of earthquakes on water and sewer pipe, cast ductile iron pipe with restrained joints proved superior to components produced in other materials, according to a paper appearing in the May 2010 issue of the Journal of the American Water Works Association.

The paper, by Michael Tucker, senior sales engineer with American Cast Iron Pipe (a company that itself produces the products in question), Birmingham, Ala., reviewed data about pipe failures during modern-day earthquakes, including Prince William Sound, Alaska, 1964; Loma Prieta, Calif., 1989; and Northridge, Calif., 1994.

“Earthquakes like these have demonstrated time and again the need for high-strength, flexible pipe with flexible joints,” Tucker said. “Whether the pipe and joints are flexible or rigid determines the ability of the pipeline to resist the motion and energy associated with earthquakes.”

The study said ductile iron pipe and joints sustained only minimal structural damage during the tremors. Asbestos-cement pipe had the worst failure rate, and plastic pipe was more likely to pull apart at the joints than ductile iron products.

“Most mid- to large-size utilities in seismic zones in this country use ductile iron pipe and joints designed for river crossings,” Tucker said. “This application has proven very effective in withstanding the effects of earthquakes.”