Ultrasonic Leak Detection: How It Works

There are a number of different techniques that exist for leak detections. Today however, we are going to focus solely on ultrasonic leak detection or “listening detectors”. (Sniffer type detectors and visual detectors are other ways to locate leaks.)

An ultrasonic leak detector generates a high frequency, energetic pulse that propagates through materials in the form of waves. When there is discontinuity in the surface (wave path), part of the energy reflects back from the flawed surface.

This appears up on the screen and the technician can record the location, size, and decibel level (dB) of the leak.

Ultrasonic leak detection being used in an industrial plant.

Rasmussen Mechanical technician using Ultrasonic Leak Detection.

How Ultrasonic Leak Detection Can Be Used at Your Facilities

Regular ultrasonic leak inspections can increase the operational reliability and reduce the costs of pneumatic equipment. We will continuously monitor:

  • Compressed air leaks
  • Vacuum air leaks
  • Valve and trap blow-by-contact
  • Monitor slow speed bearing and gear condition-contact.

According to Superior Ultrasonic Instruments:

“A good ultrasonic detector uses an electronic process called “heterodyning” to convert this high frequency leak sound to a lower range. Once there the hissing of the leak can be heard through a set of headphones, and traced to its source. Any turbulent gas will generate ultrasound when it leaks, therefore it does not matter what refrigerant you are leak testing. Ultrasonic detectors will even detect air as it rushes into a system under vacuum.”

Air Compressor Maintenance Checklist Download

Ultrasonic Leak Testing (Real World Example)

On December 28th Rasmussen Mechanical Services performed an Ultrasonic leak scans of the compressed air system in a facility.

After completing the test, there were over 41 leaks we found. Leaks were found in drain plugs, nipples, pressure regulators, positioner covers and swage fittings as well as gauge manifolds. The report included the location and size of each leak along with pictures.

Return On Investment

Most air compressor systems waste +50% of the compressors total output. More so, leaks in a compressed air system lead to increased problems in plant operations. This is due to fluctuating system pressure, excess compressor capacity, and decreased service life.

If your process relies heavily on vacuum and compressed air systems, savings can exceed 30% of the compressor’s energy costs.

This means paybacks can be achieved within 0 to 1.5 years. This payback period is dependent on the size, amount, and rate of which these leaks are repaired.

Looking For Ultrasonic Leak Detection Help?

Technician performing Infrared Thermography Inspection

Call the reliability experts at RasMech at 1-800-237-3141. We have experts that can provide help with ultrasonic leak detection as well as all of these predictive maintenance strategies:

Our reliability services department can also help you control costs with a blend of predictive, diagnostic, and scheduled maintenance practices. We can carry out performance testing and analysis on: