Damages Never Go Undetected With Ultrasonic Testing

Damages Never Go Undetected With Ultrasonic Testing

By Energy CIO Insights | Thursday, September 10, 2020

Ultrasonic testing is an updated method utilized by the operation and maintenance to detect deflects or damages in the various components of the power generation plants.

FREMONT, CA: Ultrasonic nondestructive testing, also known as ultrasonic NDT, is a technique for characterizing the thickness or internal structure of a test piece with high-frequency sound waves. The frequencies, or pitch, utilized for ultrasonic testing ideally range from 500 kHz to 20 MHz, several times higher than the limit capacity of human hearing.

In Industrial applications, the ultrasonic testing is widely used on metals, plastics, composites, and ceramics. The only common engineering materials that cannot be assessed utilizing ultrasonic testing with conventional equipment are wood and paper products.

Ultrasonic thickness gauges in the power industry are more often used to measure the damaged wall thickness of corroded process piping, tubing, and pressure vessels. The measurements process is quick and can be carried easily without requiring access to the internal structure or the need for the pipe or tank to be emptied. Other applications include thickness measurements of molded plastic bottles and containers. Even turbine blades and different precision machined or cast parts, rubber tires, and conveyor belts, fiberglass boat hulls, and contact lenses can be tested.

Sound waves travelling through a material will reflect off the flaws such as cracks and voids in predictable ways. An ultrasonic flaw detector generates and analyzes ultrasonic signals by creating a waveform display.  The waveform output is used to draw insights from by a trained operator in turn identifying hidden flaws in a test piece. The operator successfully determines the characteristic reflection pattern from a good part and then looks for changes in that reflection pattern that may any indicate flaws.

Power generation and flaw-detection use cases comprise of turbine component inspections, for surface peeling, cracks, air entrapments and flaws in composite wind blades, windmill seam weld inspections, and bond testing of silicone coatings used on high-voltage power line insulators. Ultrasonic flaw detectors are widely applied in critical safety-related and quality-related applications in a power plant. Some of the flaws consist of structural welds, forgings, steel beams, pipelines and tanks, railroad rails, power turbines and other heavy machinery, ship hulls, castings, and many other applications.

Ultrasonic imaging system produces highly detailed pictures similar to X-rays, mapping the internal structure of any component with sound waves. Phased array technology, originally innovated for medical diagnostic imaging, is used in industrial scenarios to create cross-sectional pictures.

See Also: Metals And Mining Review

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