Transducers Use Ultrasonic Guided Waves to Detect Pipe Anomalies

The technology is known as a Magnetostrictive Transducer (MsT) Collar. Photo courtesy of SwRI.

The Southwest Research Institute (SwRI) (San Antonio, Texas, USA) has created its next generation of transducers using ultrasonic guided wave technology to detect anomalies in pipes, which is designed to allow users to prevent leaks before they start.

This innovative device, which utilizes the SwRI-developed Magnetostrictive Sensor (MsS) technology, was initially showcased at the American Society for Nondestructive Testing’s (ASNT) Annual Conference in Nashville, Tennessee, USA, from Oct. 31 to Nov. 3, 2022.

MsT Collar Technology

“Pipeline corrosion resulting in leaks is very common,” says Sergey Vinogradov, a staff engineer who developed the technology with fellow engineer Keith Bartels and other SwRI staff members.

“There are only a few current methods to detect defects before they cause leaks,” Vinogradov explains. “Quite often, the pipe is repaired and re-inspected after a leak occurs. We’ve developed a technology that can consistently monitor the pipe’s condition, hopefully preventing leaks from happening in the first place.”

The technology is known as a Magnetostrictive Transducer (MsT) Collar, which was originally developed by SwRI in 2002. The updated version has a flat, thin design, which allows it to be used on pipes in tight spaces. In custom configurations, it can withstand heat up to 400 °F (204.4 °C). The new, segmented MsT design features eight sensors giving the transducer an ability to more accurately identify where corrosion in the pipe is occurring.

The MsT Collar utilizes magnetostrictive sensors, which generate and receive guided waves that propagate along an elongated structure, guided by its boundaries. This technique allows the waves to travel long distances with little loss in energy, SwRI explains. In some cases, hundreds of meters can be inspected from a single location, though obstacles such as couplings would require an additional sensor.

Eight Transducer Sensors

“Instead of using one sensor to cover an entire pipe circumference, allowing only the axial location of an anomaly to be measured, we now have eight sensors in the transducer,” Vinogradov says.

“Each of the sensors are independently connected to the electronics so that all possible guided wave signals can be acquired,” he adds. “Algorithms combine this information to better detect and locate the anomaly both axially and circumferentially, and the growth of the corrosion can be monitored by examining data sets acquired over time.”

The MsS system can send data to a remote terminal via a wireless transmitter unit or by means of a wired connection. It is designed primarily for oil and gas transmission pipelines to prevent costly and damaging leaks before they begin. However, the technology is versatile and has been used for other industrial pipes such as those used for water, heating, or in chemical plants.

More SwRI Resources

The Institute’s Nondestructive Evaluation and Sensor Systems section develops tools and techniques for nondestructive inspection, evaluation, and testing featuring guided waves, computed tomography, ultrasonics, electromagnetics, and other techniques.

For more information, visit Magnetostrictive Sensor-Based Guided Waves or Nondestructive Evaluation, contact SwRI’s Jesús Chávez at +1 (210) 522-2258.

Source: SwRI,

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