GRI to manage pipeline damage studies

The US Research and Special Programs Administration (RSPA) has contracted with GRI, Chicago, to manage research on the effects of third-party damage to pipelines. GRI will oversee work by Battelle Institute and Southwest Research Institute (SWRI) in a 2-year, $2 million program that builds on research both have already conducted. The US Transportation Department and GRI will each provide 50% of the funding.


The US Research and Special Programs Administration (RSPA) has contracted with GRI, Chicago, to manage research on the effects of third-party damage to pipelines. GRI will oversee work by Battelle Institute and Southwest Research Institute (SWRI) in a 2-year, $2 million program that builds on research both have already conducted. The US Transportation Department and GRI will each provide 50% of the funding.

Battelle will develop improved smart pigs that use magnetic flux leakage (MFL) to find and evaluate damage such as gouges caused by backhoes. DOT has sponsored Battelle research on the issue since 1996.

GRI said axial-direction MFL systems impose a magnetic field on a pipeline wall to detect irregularities and metal loss due to corrosion, but they cannot reliably detect mechanical damage. Battelle will seek to develop a MFL magnetizer orientation in the circumferential direction. SWRI will develop criteria for evaluating the effect of mechanical damage on pipe strength and life. GRI said data would be used from smart pig MFL systems to predict remaining pipeline life and establish guidelines for remedial action.

Harvey Haines, GRI manager of nondestructive evaluation research, said, "Today, there is no validated technology for establishing the effect of mechanical damage on the strength and remaining life of a pressurized pipe. Gouges or dents parallel to the pipe axis are particularly hard to assess with current systems. Under this integrated research program, Battelle, SWRI, and GRI will be able to coordinate their resources and experience."

GRI said gas pipelines use careful installation procedures, call-before-you-dig programs, periodic right-of-way patrols, and other methods to mitigate mechanical damage.

However, DOT's Office of Pipeline Safety reports mechanical damage from excavating equipment still accounted for 348 (32%) of the 1,084 reportable incidents involving gas transmission and gathering lines during 1985-97.

GRI said, "Improved in-line inspection will help prevent 'delayed failures,' which can happen months or years after the actual contact that damages the pipeline. Such failures represent only 4% of the reportable incidents, but they include some of the most noteworthy events in recent pipeline history."

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