Leak Detection with Ultrasonic Technology
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 &
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
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.
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,
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
voltages, open access or enclosed) Arcing, tracking, corona, and
partial discharge: switchgear, transformers, arresters, insulators,
motor control centers, distribution lines, and buss bars,
How Ultrasonic Leak Detection Works
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
Leak Detection Method
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
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.
ULTRASONIC COMPRESSOR INSPECTION
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
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.
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
How Ultrasonic Leak Detection works
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
BEARING & MECHANICAL INSPECTION
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
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.
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.
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
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
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.