The Problem

A dent is a local deformation in a pipeline wall. Outside forces regularly affect pipelines, often causing mechanical damages such as dents or wrinkles. In the worst-case scenarios, it can result in buckling and imminent pipeline failure. Traditionally, dents instigate high levels of localized strain and are well-known causes of pipeline failure. Having knowledge and an understanding of strain tensor is crucial for the assessment of a pipeline's integrity. The use of depth criterion in isolation may result in unnecessary digs and, in some cases, the mischaracterization of severe dents.

The Solution

Using cutting-edge software, NDT Global implements a point-wise method of calculating strain by calculating the membrane and bending strains in the longitudinal and circumferential directions. By using the recorded hi-resolution geometric data, we deliver the calculated inner and outer strains on a point-by-point basis. Taking advantage of Atlas UG's axial resolution and overlapped sensors, we use a detailed and accurate geometry of the deformation to estimate the levels of strain.

Our Ultrasonic Tools

Atlas UG

Evo Series 1.0 delivers the most accurate and reliable ultrasonic inline inspection available today. Combining a corrosion or crack assessment with ultrasonic based geometry measurement enables a comprehensive inspection in a single run.

Accurate pipe geometry measurement and detection of dents is essential for pipeline integrity management. Using ultrasonic technology ensures precise direct measurement of dents with depth resolution down to 0.1 mm (0.004 in).

Read More About It

Ultrasonic Crack Detection

Evo Series 1.0 UC fleet improves speed capabilities and resolution for crack inspections. A maximum inspection speed of 4 m/s and an axial resolution of 1.5 mm (0.06 in) has become standard. Tools can detect and size features with minimum dimension of 20 mm (0.78 in) by 1 mm (0.04 in) in base material at a POD greater than 90%.


  • All work was performed in accordance with Statoil's specifications and to complete satisfaction. The data results were precise and reliable and perfectly reflected the pipeline conditions. During the last years NDT Global has been an excellent cooperation partner for us in every respect. Precision and reliability are the cornerstones of their work.


  • Thanks to the NDT Global Engineering 'A Team', and work by the Sunbury Flowlines team, a plan was conceived to put the pig on a diet.

    BP Angola

  • NDT Global showed a profound expertise and reliability. NDT Global impressed with their quality of service provided through their personnel as well as the outstanding performance of the inspection tool providing excellent data. The final reports were delivered in due time and with excellent quality. Based on this experience and the good business relationship, we are happy to recommend NDT Global for the inline inspection services.

    Open Grid Europe