Identifying stress through magnetism

A pipeline inspection technology that can detect defects in buried steel pipelines and 3D map them at the same time was developed through a collaboration between the University of Leeds and engineering firm Speir Hunter Ltd. The portable technology draws on magnetic data and has been used to inspect over 100km of pipeline across six continents since it was commercialized in 2015.

The challenge

Many pipeline networks cannot be monitored internally and where the precise location of pipes isn’t known, operators are forced to use expensive thermal imaging to assess their whereabouts and condition. Speir Hunter saw a commercial opportunity to develop remote monitoring technology and came to the University of Leeds to help make this a reality.

The solution

Drawing on the University’s expertise in physics and electronic engineering, a multi-disciplinary team was put together to identify how magnetic fields produced by steel structures were affected by corrosive, metallurgical and mechanical stresses. Experiments were performed in the laboratory on steel bars and small-scale pipelines to investigate in precise detail the science of stress-magnetisation.

Using these experimental results, the team then built simulation models to help them understand this relationship in more detail. They developed algorithms that could process and analyse magnetic data in order to pinpoint where damage or stress had occurred in a pipeline, as well as where on the pipe it was located and how deeply it was buried.

The impact

The technology was successfully tested on above-ground pipelines, in collaboration with energy and infrastructure company National Grid and the standards, classification and risk management company DNV GL. These tests were followed by further successful field trails on buried pipes to fully validate the technology.

Spier Hunter commercialised the technology and brought it to market in 2015, applying for three patents to protect the intellectual property. They now work around the world surveying pipelines for clients, helping them identify faults more easily and carry out more cost-effective and targeted maintenance.


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