| Physical Acoustics has maintained a strong commitment to leak detection. The many years of
experience with a wide range of products have been combined to develop versatile cost-effective leak detection instrumentation for the prevention of destructive
accidents. What is AE?
Acoustic emission (AE) is a nondestructive testing
(NDT) technique which allows an operator to predict when a material under
stress will fail.
Every material "talks" under stress; audible acoustic emission signals occur when paper is torn, glass is broken or wood is cracked. Leaks also
emit AE, but usually well above the human-hearing range and long before a physical defect is seen.
Acoustic emission is the ideal preventive maintenance
technique to monitor and detect leakages for applications requiring non-intrusive
testing.
How is Acoustic Emission Used to Monitor Leaks?
An Acoustic Sensor mounted on the exterior surface of a structural component detects leak-associated sounds which are generated by the leak
source and in turn transmitted through the structure. The leak detector (electronic instrument) amplifies the acoustical signal, filters it, and then displays the
level on the front panel meter.
How do you Locate the Source?
The acoustic energy propagating from the lead source decreases in amplitude as a function of distance from the source. This is know as
signal attenuation. Knowing the attenuation characteristics of the structure in question and detecting the leak noise at several locations allow the location of
the leak to be known. This is a standard practice for leak location by acoustic emission in pipelines.
Benefits to the Customers
Acoustic emission leak monitoring and detection, when
applied in a systematic preventive maintenance program, has proven to
substantially reduce costs by eliminating visual valve inspection and
unscheduled down-time. The use of this technique totally eliminates the
need for actually dismantling valves for visual inspection in parallel
piping arrangements.
The presence of a leak can be detected by a simple 10 minute test that does not require special set-up or dismantling. For systems using valves
larger than four inches, this has resulted in cost reductions by as much as $25,000.00 per valve.
Successful Applications
Leak monitoring and detection is being successfully applied in industrial plants for petrochemical processing, steam generation and plant air
lines, where losses could cause harmful effects.
In marine applications, leak detection is being used to check valves where power generation is critical. |
For the utilities, leak detection is reducing costs at fossil fuel facilities, where down time is high and coolant systems are critical.
For pipelines, the ability to determine the location of a leak within several feet, provides an expeditious path to remediation.
PAC Leak Monitoring and Detection Systems
PAC leak detection instruments and systems are used in many diversified applications including the detection and location of both gaseous and
liquid leads in valves, vessels, pipelines and tanks. There are three families of PAC lead detection products: portable, digital and multi-channel.
Portable Leak Detectors
PAC portable leak detectors offer ease of use for quick set up and simple operation. Visual and audio indicators alert the operator to
changing conditions and indicators of leaks. Battery power allows untethered mobility for access to areas requiring inspection. Proven designs with
rugged, durable construction assure high quality service for the life of the system.
Digital Leak Detector
The latest digital electronics enhances the performance of this advanced instrument. Data storage locks in the visual and audio indicators
of changing conditions and indications of leaks. The operator maximizes inspection capability while eliminating any errors in logging test results.
Computer interface downloads stores readings for permanent record, archiving or further analysis. High sensitivity over a broadband of frequencies is ideal for
diverse applications of leaks in a variety of structures.
Valve-Squeak Leak Detector
Designed for operations and maintenance personnel to perform frequent valve checks in their units, Valve-SqueakTM is an easy-to-use through-valve loss detection system. Small enough to fit in your pocket, Valve-SqueakTM, isolates leaks of any size and in any valve and saves your company money.
Multichannel Computerized Systems
Ideal for permanent monitoring of large structures and pipelines and for integration in control room systems, these computer-based systems
utilize unique software for tracking long-term monitoring conditions, while simultaneously reflecting instantaneous results and alarm status.
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