How Ultrasonic Technology Is Solving the Thick-Wall Challenge of HDPE Mining Pipelines

Mining pipelines have some of the thickest walls in the industry, but that same thickness presents significant challenges for in-line inspection. 

Modern in-line inspection (ILI) technologies were originally developed for the vast network of oil and gas pipelines that span continents and run beneath the sea.  

In these applications, operators balance safety, pressure requirements, and cost by selecting steel pipelines with wall thicknesses typically ranging from 8 to 20 mm. 

To put that into perspective, a pipeline carrying methane across hundreds of kilometres may rely on little more than the thickness of a pencil to safely contain its contents. 

Mining slurry pipelines are built to meet a very different set of demands.  

Typically shorter and simpler than transmission lines, they are designed to withstand years of continuous exposure to highly abrasive slurry.  

To maximise service life, operators select thick-walled HDPE pipe, with wall thicknesses ranging from 30 mm to well over 120 mm—comparable to the height of a deck of playing cards. 

While this exceptional wall thickness extends pipeline life, it also makes inspection more difficult.  

HDPE attenuates ultrasonic energy far more than steel, requiring inspection signals to penetrate both a highly absorptive material and substantially thicker walls. It also rules out inspection by magnetic flux leakage (MFL), which requires ferromagnetic materials. 

Meeting these challenges requires UT tools engineered specifically for HDPE applications: larger transducers, optimized ultrasonic parameters, and advanced signal processing. 

In recent years, in-line inspection companies (including Dexon Technology) have stepped up to the plate to produce tools that can deliver high-quality wall thickness and geometric data in a single run. 

Rather than replacing pipelines based on conservative assumptions, ILI technology allows operators to make maintenance decisions based on thorough and precise inspection data—reducing unnecessary replacements or shutdowns. 

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Dexon Technology has developed a fleet of ultrasonic in-line inspection tools purpose-built for HDPE mining pipelines and backed by decades of experience inspecting challenging pipeline systems around the world.  

Whether your assets are constructed from HDPE or steel, our inspection technologies provide the data needed to keep them operating safely, reliably, and efficiently.