Transmission Main Leak Detection and Condition Assessment: Brazil Trade Mission 2012
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Transcript of Transmission Main Leak Detection and Condition Assessment: Brazil Trade Mission 2012
Transmission Main Leak Detection and Condition Assessment: Brazil Trade Mission 2012
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Corporate Overview
• Formed in 2003.• Based in Toronto.• Original focus was on correlation based Leak Detection
Equipment, specifically for PVC.• Developed Non Destructive pipe condition assessment
technology• Changed focus to service offerings:
▸ Leak detection for Large diameter mains▸ Condition assessment for ferrous and asbestos cement mains
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Agenda
• Correlation Theory Review• Echologics • Key Advantages• Leak Detection Case Studies• Condition Assessment Background• Condition Assessment Case Studies• Summary
Correlation Theory
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Correlation: a Review • Old technology: proven on metallic distribution mains• Manufacturer’s began to work on plastic and other types of
pipes: made claims that could not be consistently achieved!• Required a different approach to:
▸ Sensors▸ Signal Processing▸ Amplifiers
• Echologics achieved some extraordinary success, other manufacturers immediately introduced ‘trunk main correlators’, but have never achieved our level of success
• Development continues; now on our 5th generation of hardware
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Correlation Theory• Leaks make noise• Time of flight technology• Correlation function:
▸ Leak bracketed with 2 Sensors▸ Leak noise takes longer to arrive at Sensor 1 than Sensor 2▸ Correlator measures time difference to identify exact leak location
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Why is Echologics Successful
• Advances in sensor design, signal processing, correlation algorithms
• Advances in post processing of data• Advances in field techniques• It is as much about the people, as it is about the equipment
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Sensor development• We have done extensive R&D into
plastic and transmission main sensor requirements, developed both hydrophones and accelerometers for large diameter
The People• We have an intense training
program and detailed field / data analysis processes
• We have a young, passionate team of engineers
Echologics CorrelationAdvantages
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Advantage and Disadvantages
• Advantages:▸ Easily implemented with existing fittings▸ No requirement to close service take offs or laterals▸ No requirement to alter the flow in the pipe▸ Can ‘see’ leaks many km away; will find largest leaks first▸ Will find small leaks (typical results 2 LPM on 1500mm pipe at 3.5 bar,
1100m)• Disadvantages:
▸ Will not find very small leaks (<1LPM)▸ Accuracy of location needs to be carefully verified
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Technology ComparisonTechnology Pros Cons
Traditional Correlation • Non-Intrusive and Non-destructive
• Poor performance on PVC and Large Diameter (LD) mains
Echologics Correlation • Same as above• Works on PVC and
LD mains• Cost Effective
• Cannot find small leaks (<1 lpm)
• ‘Averaged’ condition assessment results
In-Pipe Tethered and Free Swimming
• Can find small leaks
• Works on long sections of pipe with minimal access
• Intrusive• Special Insertion
Points are required• Isolation of all
laterals is required
Leak Detection Case Studies
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Case Study: SABESP
• Leak discovered by Smart Ball Pilot• Dry hole had been dug based on Smartball location• Requested by Genival Abdias to try and pinpoint the leak• Echologics correlated the leak to within <1m accuracy
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Site Location
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Leak Location Excavation
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Successful Leak Location
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• Echologics performed a transmission main leak detection pilot survey on 8km of UWNJ transmission mains▸ 24” to 42” diameter
• Testing revealed 5 leaks• One major leak discovered on a pipeline section outside of
the boundaries of the original test plan• We first saw this leak 3 km from the eventual location
Case Study: United Water New Jersey
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Out of Bracket Leak DetectedCorrelations provided evidence of leakage outside the current test area
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Isolated Leak Under a Stream• Correlation across the river crossing revealing a prominent
peak 40m east of fitting on the main
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UWNJ 42” RCP Repair Pictures
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Other Examples:
• Thames Water, England• Bristol Water, England• Las Vegas Valley Water Department• Springfield, Massachusetts
▸ Echologics confirmed 2 leaks that was already discovered by expensive in-pipe technologies - 36”(915mm) and 48” (1200mm) main
• Sydney, Australia• Barrie, Ontario• New Orleans
Condition Assessment Background
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Remaining Pipe Wall Thickness Measurement
• Metallic pipes lose thickness from internal and external corrosion
• Asbestos cement pipes lose “effective thickness” from aggressive waters leaching calcium out of cement and weakening walls
• Physical wall thickness doesn’t change, but the pipe loses structural stiffness and strength
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Velocity Measurement
Wave propagation velocity (v) = D/ΔT, where ΔT is time delay between signals 1 and 2
Noise Source
Measure the sound velocity
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Minimum1 Average2 Wall Thickness1. Minimum around
the circumference
2. Averaged along the length
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Las Vegas, NV: LVVWD Pilot• Two sections of 6” AC pipe tested• .73” remaining structural thickness was measured by
Echologics• Results indicated that pipe met requirements of PC200• Excavated pipe to confirm results• Testing confirmed that our results accurately represented
the remaining structural thickness of the pipe
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Las Vegas: Velocity Measurement & Results
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Las Vegas, NV: Excavated Pipe
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Results of 14” lab testing
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White area has lost structural integrity
Pink area represents structurally sound concrete
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Newark, NJ: Pilot on cast iron pipe• Pilot study on cast iron pipe installed in 1910• Pipe had been chosen for cement mortar lining as a
rehabilitation technique• Our study determined that it was highly degraded and
required a structural lining• We also found a leak during the study, losing about $20,000
worth of water a year
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Newark, New Jersey
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Pit #1 - Valve
Pit #2Pit #3
Fire Hydrant
Service Leak at House #195
Average Pipe Wall Thickness of 0.18”, 63.9% loss
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Newark, New Jersey
33ConfidentialUse pursuant to
Company instructions
This is the remaining structural thickness!
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• Dayton, Ohio• Sweetwater, California• Hamilton, Ontario• Chicago, Illinois
▸ Successfully identified 3000ft section of reinforced concrete cylinder pipe with a significant number of wire breaks
• Calgary, Alberta• Maple Ridge, British Columbia• Bloemfontein, South Africa
Other Examples:
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Summary• Echologics has pioneered the effective use of correlators on large diameter
pipe, and continues to develop the technology• In North America, we are now considered a viable alternative to insertion
technologies: numerous successful studies have been completed• Claims made by other manufacturers continue to throw the technology into
doubt• In several projects we have been directly compared to Sahara and have
found the same leaks• Our condition assessment technology can accurately determine the
remaining structural wall thickness of pipes• There is return on investment from:
• Prioritizing which pipes require rehab or replacement• Performing leak detection simultaneously• Ensuring the correct decision is made with respect to rehab or replacement