Guided Wave Long Range Ultrasonic Testing (GWLRUT), also known as Guided Wave Testing (GWT), is a long-range, non-destructive testing method that uses low-frequency, guided ultrasonic waves generated by transducer rings to inspect long, in-service, or inaccessible pipes, rails, and plates for corrosion, erosion, and cracks in material from a single test point.
Typically used to inspect pipes, GWLRUT can act as a high speed flaw detector over long distances, enabling 100% coverage of the pipe wall. The process works by sending sound wave signals from a ring of transducers. These signals travel along the pipe wall, using the structure itself as a guidefor the waves. When the waves encounter a defect such as cracking or metal loss as a result of corrosion or other changes in the wall thickness, a pulse echo reflects back that can be analysed to identify, characterise and locate the defect.
Capable of providing rapid screening or large and hard-to-access areas, GWLRUT can be used with sleeved or buried pipes and requires minimal insulation removal. GWLRUT is effective for the inspection of ‘unpiggable’ pipelines and structures that are difficult to inspect by other means.