Sometimes you can even see the results of leaks when the escaping air stream impacts on something that moves.
Most of the time though, you can't hear or see air leaks in the plant. There is too much noise and activity to spot them.
The surefire method of finding compressed air leaks in the air system in your plant, and quite likely saving a lot of money as a result of stopping those air leaks, is through ultrasonic leak detection.
Ultrasonic leak detection can generate savings in all industrial plants in two ways. First is through energy savings as a result of stopping the leaks detected in compressed air or gas systems, vacuums, steam traps, tanks, window seals, etc.
The second way savings can be generated is by using ultrasonic detectors to locate mechanical malfunctions such as worn bearings, broken gears, slop of mechanical movable parts within casings, to name just a few.
Ultrasonic detectors work by listening for leaks or vibration within a frequency normally inaudible to humans. The frequency band is those above the 20 K Hz level.
Leaking compressed air or electrical flashover, sparks generated by a short of electrical malfunction, can generate ultrasonic levels of noise. These levels of sound can be isolated, as the equipment filters off sounds from the surroundings. Ultrasonic leak detectors can be used in noisy environments very successfully.
Some ultrasonic leak detectors have a new form of ultra-search technology incorporated in them. This improves both close leak seeking and the detection of leaks at a distance of up 6 meters. They also offer analogue and digital leak detection.
When using analogue leak detection with an integral hearing protector a buzz generated by a leak can be heard in the headphone. The sound level depends on the size of the leak.
If seeking a very small leak that is close by, the directional probe can be applied and optimum listening sensitivity is achieved. This analogue detection is very precise, both close and at distance.
When using digital leak detection without the hearing protection of the headset, the unit makes use of newly developed digital technology. The ultrasound transforms into digital signal which the operator can both hear and see as a sound in the headset and a flashing light from the detector.
A faster sound tempo and the faster pulse of light indicates that the leak is close and provides a clue to the size of the leak as well.
Digital leak detection is very fast and handy, but not as precise as analogue detection.
Ultrasonic leak detectors are an essential and necessary tool to make sure you can find all the leaks in the plant. Sealing those leaks is what will save your company energy costs and quite likely some compressor maintenance costs as marginal compressor won't have to work quite so hard to produce all that wasted compressed air.
I thank Mr. Hugh Gallagher of Logis-Tech Associates in Glasgow Scotland for this information and authorization for the use of the photos he provided. If you have any questions about their ultrasonic leak detection, Hugh can be contacted at www.logis-tech.co.uk.