Preventing Pipeline Failures Using Ultrasonic Crack Inspection 


Pipelines are often considered to be the lifeline of modern civilisation because of the role they play in the production processes of different industries, including oil and gas, pharmaceutical, food and beverage, and many others.  However, these pipelines often suffer from neglect and lack of maintenance because most of these pipelines remain buried. Pipeline cracking is a common defect that very easily leads to failures such as leaks, decreased structural integrity, and loss of containment. In extreme cases, catastrophic explosions may also be caused by pipeline cracks.       

Though there are many ultrasonic crack inspection methodologies, ultrasonic testing is more efficient than others. As a result, this technology is an integral part of the quality control and management processes of many asset owners.  

An Overview of Ultrasonic Technology 

The term ultrasonic refers to sound waves with higher frequencies compared to the human hearing’s audible limit. These sound waves are capable of generating data that can provide valuable insights for better decision-making.  

As the waves travel through liquids, solids, and gases, they encounter different boundaries. This results in certain portions of the wave getting reflected back to a receiver. This is the underlying principle of ultrasonic flaw detection (UFD) for pipelines.  

Typically, an ultrasonic testing unit comprises a receiver/pulser, a display device, and an ultrasonic transducer.  High-voltage electrical pulses are generated by the receiver or pulser.  The transducer is powered by the voltage from the pulser, resulting in the generation of high-frequency ultrasonic wave energy.  

While propagating through different boundaries, some of the wave energy is reflected back to the receiver when an anomaly (such as a crack) or a boundary is encountered. The transducer converts the sound wave to an electrical signal, which is shown on a display screen. Apart from pipeline flaws, ultrasonic testing also reveals thickness, orientation, size, and other pipeline features.  

Pipeline Crack Inspection Using Ultrasonic Technology 

Angle beam testing and straight beam testing are the two main ultrasonic testing methods for finding cracks in pipelines. Cracks and other defects parallel to the object surface are identified by the straight beam testing method. This method is also used for the identification of porous locations and voids. On the other hand, discontinuities and cracks that are tilted with reference to the pipelines’ longitudinal axis are located by the angle beam technique.      

Benefits of Ultrasonic Pipeline Crack Inspection 

One of the key benefits of ultrasonic inspections is the versatility and speed it offers compared to other inspection methodologies. Discussed below are some other advantages of this technique.  

  • This inspection method is sensitive to surface as well as subsurface discontinuities. As a result, early onset of structural issues can be detected.  
  • Compared to other non-destructive testing methods, ultrasonic sound waves have a higher depth of penetration.  
  • Only single-side access is required for some ultrasonic testing techniques, and can be used for the inspection of pipelines that can’t be accessed easily.  
  • Can be mobilised and deployed quickly because very little part preparation is required. 
  • Results are available almost instantaneously.  
  • Detailed visual images of defects can be produced using automated imaging systems.    

To find out more about ultrasonic or any other pipeline inspection technique, please contact us immediately at Austeck.