Ultrasonic

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Ultrasonic Gas Leak Detection
EVERY LIFE HAS A PURPOSE
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Ultrasonic Gas Leak Detection
Increase detection reliability and reduce risk as
ultrasonic gas leak detection provides instant
and verifiable detection of gas leaks. The
ultrasonic technology will detect pressurised gas
leaks instantly regardless of gas dilution and
ever changing weather conditions found on most
on- and offshore installations in the
petrochemical industry.
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Application Area

• Applications for Ultrasonic Gas Leak Detectors
• Instant detection of flammable gas leaks
• Fixed installations
• Explosion hazardous areas
• Pressurized gas installations
• Outdoor or semi outdoor ventilated areas
• Electrical connection to DCS system or fire and
  gas panel

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Ultrasonic Gas Leak Detection
WHAT is Relevant to Detect?
In plant installations with pressurized flammable
gases, it is relevant to detect gas leaks that
can accumulate into a potentially explosive gas
cloud.
WHEN is it Relevant to Detect?
As fast as possible - to prevent build-up of
dangerous concentrations. Accumulation of gas can
lead to explosions.
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What Creates an Explosion?
Three main factors determine if a hydrocarbon gas
leak can create a catastrophic explosion 1)
Oxygen 2) Ignition Source 3) Gas Concentration
The amount of gas released over time from a gas
leak is known as the LEAK RATE and has units of
kg/s.
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Leak Rate vs. LEL
Important Parameters to Know in a Gas Leak
Detection Situation
Lower Explosive Level ( LEL) A concentration
measurement in a pre-defined point that may
create a true picture of the nature of the gas
leak.
Leak rate (kg/s) Detection related to the leak
rate, makes it possible to introduce a
performance standard for the gas leak detection
system. Example Gas leaks with a leak rate of
0.1 kg/s or more must be detected.
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Real Gas Leak Test with Ultrasonic Detectors
Live Gas Leak Test on a North Sea Off-Shore
Installation Within 4-5 meters the gas
concentration around the leak was below 5 LEL!
None of the existing gas detection systems
alarmed!
Leak size 3 mm Gas pressure 55 bar (808 psi)
Leak rate 0.06
kg/s
The ultrasonic gas leak detector detected the
leak up to 19 meters away!
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Ultrasonic Gas Leak Detection

• Main Characteristics
• Instant acoustic gas leak detection
• Detects gas leaks at a leak rate of 0.1 kg/s
• Detection radius up to 20 meters away
• Unaffected by changing wind direction and fast
  dilution of gas
• Minimal maintenance and calibration requirements

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Acoustics and Gas Leaks

• Gas molecules travel from high pressure to low
  pressure
• Hissing sound
• Acceleration of gas produces white noise, which
  consists of both audible and ultrasonic sound
  components
• Acoustic detectors filter the audible range
  responding to sound in frequencies from 25 kHz to
  approximately 50 kHz far higher than
  frequencies human hearing can detect
• Ultrasonic leak noise is proportional to the leak
  rate

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Leak Detection Range

• The detection range of an ultrasonic gas leak
  detector depends on these variables
• Leak size
• Pressure
• Ultrasonic background noise

Leak size and gas pressure determine the
acoustical ultrasonic noise level generated from
the leak.
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Directional Characteristics

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Limitations

• Traditional Technologies Can Be Problematic
• Changing wind directions
• Gas dilution
• Direction of the leak
• Acoustic Technology Limitations
• Low pressure (normal application of 10 bar and
  higher)
• High background noise ( gt 90 dB) although rare

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UltraSonic EX-5 Gas Leak Detector

• Main Features
• Senssonic integrated acoustic self-test
• Standard 4-20 mA analog output
• RS 485 serial digital communication interface
• Explosion-proof housing in solid 316L stainless
  steel for extreme environmental conditions
• Minimal calibration and regular maintenance
• Robust microphone technology to ensure long MTBF
• FM, CSA, C-UL, ATEX, IECEx, GOST certified for
  hazardous areas

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How to Ensure Failsafe Operation?
UltraSonic EX-5- Test Transducer

• Senssonic Built-In acoustic Integrity Test
• External loop configuration
• Controlled functionality and integrity test every
  15 minutes
• No un-revealed failures between inspections
• 4-20 mA signal indicates any abnormalities (to 1
  mA for 5s)

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Installation Practice

• Allocation of Ultrasonic Detectors Based On
• Plant details and layout
• Ultrasonic background noise mapping survey
• Installation of Ultrasonic Gas Leak Detectors
• System Commissioning, Performance Verification
• Test with portable test and calibration unit
• Actual leak simulation with nitrogen

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Installation on Existing Installations
Background noise mapping and detectors allocation
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New Installations - Allocation

• Detectors installed at elevated position (approx.
  2 m above potential leak sources) with the sensor
  head facing down.
• Avoid solid decks or big vessels blocking path
  between leak spots and detector. Heavy piping
  does not block the sound to the detector.

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Commissioning, Testing, Calibration

• Commissioning
  
• 1701 Portable Test and Calibration Unit
• Live leak simulation of 0.1 kg/s gas leaks
  (using nitrogen gas)
• Testing and Calibration
  
  
• 1701 Traceable, calibrated test and calibration
  unit
• Gain test and field calibration if required
  (every 6-12 months)

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Typical Applications

• Offshore oil and gas platforms
• Onshore oil and gas terminals
• Floating production storage and offloading
  vessels (FPSOs)
• Gas compressor and metering stations 
• Underground gas storage facilities
• Downstream chemical processing plants (e.g.
  ethylene, methanol, ammonia, and propylene)
• Hydrogen storage facilities
• Refineries
• LNG/GTL trains (plants)
• LNG re-gasification plants
• Gas turbine power plants

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Installations Worldwide

• Most Major End-Users in Oil Gas are
  Implementing UltraSonic Detectors for Projects
  Worldwide
• North Sea England, Denmark, Holland, Norway
  (Sleipner, Gullfaks)
• The Americas USA, Canada, Trinidad Tobago
  (Cannonball)
• Middle East UAE, Oman (Saih Rawl, Saih Nihyada,
  Al-Kawther, Harweel)
• Far East/Central Asia China (Bohai Bay),
  Malaysia (Shell Bintulu), Pakistan (Rehmat),
  Indonesia (Tangguh)
• Africa Equatorial Guinea (Marathon ALBA),
  Algeria (Hassi Berkine)
• Caspian Sea Region Azerbaijan (Shah Deniz),
  Russia (Sakhalin II), Kazakhstan (Kashagan)

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Conclusions

• Why Ultrasonic Gas Leak Detection?
• Reduce risk
• Instant and reliable detection
• Unaffected by changing weather conditions
• Possible to pre-define safety standards and
  verify system performance
• No undetected failures Built-in self-test
  function
• Cost effective reduced total cost of ownership

For more information, visit our website
www.msanet.com
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UltraSonic EX-5 Gas Leak Detection
EVERY LIFE HAS A PURPOSE