Why Complex Geometries Matter in Supply Line Inspection

The complex routes taken by supply lines inside refineries, tank farms, and processing facilities are essential to operations—but they can become major obstacles come inspection time.

Long-distance transmission pipelines, which most people picture when they hear the term “oil pipeline,” may run for hundreds of kilometres along relatively straight and predictable routes.

Supply lines are different.

These pipelines move products between storage tanks, pumps, heat exchangers, processing units, and other equipment throughout a facility—snaking their way between sections and optimized to reduce the time between two points.

As a result, supply lines often contain challenging geometric features, including: 

• Tight-radius bends 
• Back-to-back elbows 
• Vertical sections 
• Tees and valves 
• Short spool pieces 

These features allow the interconnected parts of a facility to operate efficiently, but they can create significant challenges for in-line inspection.Conventional ILI tools are generally designed for long, relatively uniform transmission pipelines. In compact facility piping, a rigid tool may struggle to pass through closely spaced bends or remain stable as it moves between horizontal and vertical sections.

Tight bends can place substantial mechanical loads on the tool. Consecutive elbows may require it to change direction before fully straightening, while valves, welds, and internal restrictions can further reduce the space available for safe passage.

Complex geometry can also affect inspection data. Ultrasonic sensors must remain correctly positioned and reliably coupled to the pipe wall throughout the run. Loss of contact may reduce measurement quality and inspection coverage.

Dexon Technology developed Flexi-ILI to address these constraints.

Its flexible construction and novel, patent-pending sealing approach allow the tool to navigate demanding layouts while maintaining reliable ultrasonic inspection coverage.

For supply lines, successful inspection begins before a defect is detected. The tool must first be capable of safely navigating the full geometry of the pipeline.