Ultrasound is a robust predictive maintenance (PdM) technology with many practical applications for manufacturers. Ultrasonic testing equipment samples a band of ultrasound (most likely above 25 kHz) and converts it into an audible frequency range. This provides a non-intrusive method of detecting a wide variety of faults in a facility’s assets. Common uses of ultrasound include:
- Leak detection in pressure and vacuum systems
- Bearing inspection
- Steam trap inspection
- Detect pump cavitations
- Check integrity of seals and gaskets
- Corona discharge
Corona discharge is an electrical discharge created from the ionization of a fluid or gas surrounding an electrically charged conductor. Corona creates a steady buzzing sound in the 50 kHz – 60 kHz range, making it easy to detect with ultrasound. Cavitation refers to the formation and implosion of bubbles or cavities in a liquid. Cavitation is common in pumps when blockage occurs or when there are issues with suction, and it can be easily diagnosed with ultrasound. For more information about using ultrasound for steam trap inspection, read this post.
Leak detection is the most common utilization of ultrasound in industrial settings. When a gas leaks, it moves from an area of high pressure to an area of low pressure, creating turbulence. The ultrasonic components of the turbulence can be scanned, and will be loudest at the point of a leak. The spot of the leak can be tagged and documented, informing the technician who will ultimately fix the leak.
Ultrasonic leak detection is a popular maintenance tool because it offers an immediate return of investment. Compressed air is one of the most expensive utilities in a plant, and compressed air leaks add to the cost significantly. Leaks of other gasses, such as argon or nitrogen, are even more costly. In essence, money leaks out of the plant. Performing ultrasonic leak detection creates a major opportunity for cost avoidance, and will lead to reducing the carbon footprint of the facility.