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Leak Detection

Leak  Detection  with  Ultrasonic  Technology

Ultrasonic detectors not only provide information qualitatively by “hearing” the sounds through the operator’s headphones. They also can measure the sound quantitatively, via incremental readings on a meter, visually displaying sonic patterns that can be data-logged. By noting sound intensity levels (usually as dB), users can obtain estimated CFM valves to help calculate leak cost.

What Creates Ultrasound?
  • Friction - bearings, gears
  • Impact - valves, pumps
  • Turbulence - gas leaks, vacuum leaks
  • Electrical - arcing, corona discharge
Applications of ultrasonic leak detection

Detecting & Pinpointing exact location of Pressure Leaks (Compressed Air, Gas etc.) & Vacuum Leaks in pipes, vessels, Reactors, Columns.Valve seat & stem leak detectionExhaust system leaksTube leaks in Heat Exchanger, Boiler, CondensorsSteam Trap inspectionElectrical Inspection & detecting Arching, Corona & TrackingGear Box

What are the Advantages of Ultrasonic Technology?
  • Provides the earliest warning signs
  • Many problems are only detectable in the ultrasonic range.
  • Ultrasound is the first indicator of mechanical wear
  • Instantaneous
  • Audible noise is ignored, increasing the selectivity of the ability to pinpoint.  Therefore, more accurate at pinpointing problems.
  • Isolation of faulty components, even internally is possible.
  • More versatile – It can be used for several applications.
  • Non-Destructive – Does not adversely effect or interfere with the component under test.
  • Ultrasonic testing can be performed while the equipment is operating.


Leak Detection:

Pressure or vacuum systems, seals and gaskets, wind noise, hatch leaks, vacuum bagging, compressed air, compressors, valves, steam traps, heat exchangers, boilers, condensers, building envelope, glove box, distillation columns,

Mechanical Inspection:

Bearing faults (all speeds), lack of lubrication, prevent over lubrication, compressors, pumps (cavitations), motors, gears/gear boxes, hydraulic systems, fans, couplings, trending, trend reports, spectral analysis

Electrical Inspection:

(All voltages, open access or enclosed) Arcing, tracking, corona, and partial discharge: switchgear, transformers, arresters, insulators, motor control centers, distribution lines, and buss bars, breakers/disconnects

How Ultrasonic Leak Detection Works

During a leak, a fluid (liquid or gas) moves from a high pressure to a low pressure. As it passes through the leak site, a turbulent flow is generated. This turbulence has strong ultrasonic components which are heard through headphones and seen as intensity increments on the meter. It can be generally noted that the larger the leak, the greater the ultrasound level.

Leak Detection Method

Ultrasound is a high frequency, short wave signal. The intensity of the ultrasound produced by a leak drops off rapidly as the sound moves away from its source. For this reason, the leak sound will be loudest at the leak site. Ultrasound is considered fairly "directional" and therefore, locating the source (i.e. the location) of the leak is quite simple.

Heat Exchangers, Boilers, Condensers


Leak Detection of heat exchangers, boilers and condensers most often involves inspection of three generic areas: tubes, tube sheets and housings. While it may be necessary to take a unit off-line to inspect for leaks, with ultrasound, it is often possible to perform an inspection while on-line or at partial load.

How Ultrasonic Leak Detection Works
During a leak, the fluid will flow from high pressure to low pressure producing a turbulent flow at the leak site. This turbulence has strong ultrasonic components, which are sensed by the Instrument and translated into the audible range where they are heard in headphones and seen as intensity increments on a meter.


Compressors are the heart of any compressed gas system. Routine inspection and maintenance can prevent unplanned downtime. Although any type of compressor can be inspected ultrasonically, the most common application center around larger reciprocating types. Specifically, valve function in these compressors is critical. Minor valve leaks can rapidly lead to large leaks which can effect production and impact on plant safety.Ultrasound is the perfect technology for compressed air system leak inspection.

How Ultrasonic Compressor Inspection Works 

As with any mechanical movement, there is a "normal" operation and a "deviation". In the case of valves, normal function is the typical open/close movement. Ultrasonically this will be observed as a rhythmic movement. When valve movement changes due to leakage or sticking, the sound pattern changes. Each condition has ultrasonic components that can be sensed and monitored by the Ultraprobe. Due to the short wave, high frequency nature of ultrasound, the sounds produced by a compressor valve can be isolated, which provides a clear test result.

Valve   Testing  


When valves leak or fail, it can be extremely costly in terms of product quality, safety and energy loss. Valve operation effects the way fluids will flow through a system. There are great differences in the way particular valves work (for example, control valve versus safety valve).

How Ultrasonic Leak Detection works

As fluid moves from the high pressure side of a valve through the seat to the low pressure side, it produces turbulence. This turbulence generates ultrasound which is detected by the Ultraprobe and translated, via heterodyning, down into the audible range. The translated ultrasounds are heard through headphones and seen as intensity increments, usually decibels on a display panel. High frequency tuning allows users to adjust for differences in fluid viscosity (i.e. water vs. steam) and reduce any interference from stray pipe noises.


Today, more than 50% of all motor operated machine failure is caused by faulty bearings. This one problem not only amounts to severe production downtime but significant profitability loss as well. Ultrasound is among the most widely used and most precise technologies to inspect warning signs in bearings and hundreds of other applications – allowing inspectors to record, trend, analyze and report potential problems long before failure.

Ultrasound inspection provides early warning of bearing failure, detects lack of lubrication, prevents over lubrication and can be used on high as well as low speed bearings. In addition, since ultrasound is a high frequency, short wave signal, it is possible to filter out stray, confusing background noises and focus on the specific item to be inspected. Basic inspection methods are extremely simple and require very little training.

Ultrasonic condition analysis is straightforward. Users can observe sound levels while simultaneously listening to sound quality and record both sound and data for analysis through specialized software.



When electrical apparatus such as switchgear, transformers, insulators or disconnects and splices fail, the results can be catastrophic. This is just as true in industrial plants as it is in the power transmission and distribution side. Electrical discharges such as arcing, tracking or corona are all potential for equipment failure. In addition, the problems of RFI and TVI impact on our valuable communication networks. If left undetected, these conditions can become a source of an arc flash incident, which can result in severe injury or death. Arcing, tracking and corona produce ultrasound and are detected by Ultrsound.

Preventing Arcing, Tracking, and Corona with Ultrasound

When electricity discharges from high voltage lines or when it jumps across a gap in an electrical connection, it disturbs the air molecules around it and generates ultrasound. Often this sound will be perceived as crackling or frying; in other situations it will be heard as a buzzing sound. When inspecting components such as insulators, cables, switchgear, buss bars, relays, contactors, and junction boxes, the three most common electrical problems, arcing, corona, and tracking can all be detected by ultrasound in time to prevent failure conditions from occurring.

Ultrasound combined with infrared technology, are the best tools to detect and prevent electrical outages and failures. Infrared can detect heat generated by arcing and in most instances tracking; it will not sense corona. Ultrasonic testing is often used for identifying tracking, arcing and corona. While infrared instruments will detect emissions related to heat, ultrasonic equipment detects high frequency components of ionization produced by these potential failure conditions. These instruments translate ultrasound by heterodyning (an electric translation process), these inaudible sounds down into the audible ranges. Specific sound quality of each type of emission is heard in headphones while the intensity of the signal is observed on a display panel. By listening for a crackling, frying, or buzzing sound, a user will be able to quickly locate the source of the potential problem area. Ultrasound then provides the ability to accurately analyze the emissions via spectral analysis software for accurate diagnosis.




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