Dexon TechnologyUltrasonic Testing
Ultrasonic testing (UT) is widely used throughout the non-destructive testing industry. Unlike other inspection methods, UT is capable of inspecting a wide range of materials including non-ferrous metals, ceramics, concrete, and plastics like High-Density Polyethylene (HDPE).
Pulse-echo Ultrasonic Testing
Pulse-echo UT testing uses a transducer to emit and receive ultrasonic pulse waves. The UT waves pass through the material with defects and changes in material density reflecting echoes back to the transducer. Measurements of the material can then be made based on the time between receiving UT echo signals. One common application for UT testing is ultrasonic thickness measurement allowing inspectors to gain accurate measurements of external dimensions and internal defects.
Top of the Line Corrosion
Top of the line corrosion (TLC) is a severe form of corrosion that affects the top of the inside of a pipeline wall usually between the 10 and 2 o’clock positions. Corrosion is caused by the condensing of water vapor containing corrosive gases such as CO2, H2S, and organic acids. TLC causes rapid severe deterioration of metals with deep pitting. Due to the narrow width of pitting corrosion sampling density plays a large role in the probability of detection of these defects.
UT Sampling Resolution
The below video illustrates the differences in probability of detection (POD) of top of the line corrosion (TLC) pitting between different sampling densities. A sample piece of pipe wall has been used to show the varying metal loss depths detected over 3 different sampling densities, from standard pipeline operator forum (POF) approved resolution (10mm x 10mm), high-resolution sampling density (5mmx 5mm), and Dacon’s ultra-high-resolution (3mm x 3mm) UT inline inspection tools.
Ultrasonic (UT) In-Line Inspection Sampling Resolution
Contact a Dacon inspection expert to see how we can ensure the integrity of your pipeline.