Transcript Ultrasonic Gas Leak Detection

Ultrasonic™ Gas Leak Detection
EVERY LIFE HAS A PURPOSE…
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.
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
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.
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.
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.
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!
The ultrasonic gas leak
detector detected the leak
up to 19 meters away!
Leak size: 3 mm
Gas pressure: 55 bar (808 psi)
Leak rate: 0.06 kg/s
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
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
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.
Directional Characteristics
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 ( > 90 dB) – although rare
UltraSonic EX-5 Gas Leak Detector
Main Features:
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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
How to Ensure Failsafe Operation?
UltraSonic EX-5- Test Transducer
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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)
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
Installation on Existing Installations
Background noise mapping and detectors allocation
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.
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)
Typical Applications
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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
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)
Conclusions
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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
UltraSonic™ EX-5
Gas Leak Detection
EVERY LIFE HAS A PURPOSE…