Transmission Main Leak Detection
and Condition Assessment:
Brazil Trade Mission 2012
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
2
Agenda
•
•
•
•
•
•
•
Correlation Theory Review
Echologics
Key Advantages
Leak Detection Case Studies
Condition Assessment Background
Condition Assessment Case Studies
Summary
3
Correlation
Theory
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
5
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
6
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
7
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
8
Echologics
Correlation
Advantages
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
10
Technology Comparison
Technology
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 • Intrusive
• Works on long
• Special Insertion
sections of pipe with
Points are required
minimal access
• Isolation of all
laterals is required
11
Leak Detection
Case Studies
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
13
13
Site Location
14
Leak Location Excavation
15
Successful Leak Location
16
Case Study: United Water New
Jersey
• 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
17
Out of Bracket Leak Detected
Correlations provided evidence of
leakage outside the current test area
18
Isolated Leak Under a Stream
• Correlation across the river crossing revealing a prominent peak
40m east of fitting on the main
19
UWNJ 42” RCP Repair Pictures
20
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
21
Condition
Assessment
Background
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
23
Velocity Measurement
Noise Source
Measure the sound
velocity
Wave propagation velocity (v) = D/ΔT, where ΔT
is time delay between signals 1 and 2
24
Minimum1 Average2 Wall Thickness
1.
Minimum around
the circumference
1.
Averaged along the
length
25
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
26
Las Vegas: Velocity Measurement &
Results
Program Input
Pipe Diameter (m)
Output
Wall thickness (mm)
Wall Thickness (in)
0.1524
18.5
0.73
27
Las Vegas, NV: Excavated Pipe
28
Results of 14” lab testing
29
Pink area represents structurally
sound concrete
White area has lost structural integrity
30
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
31
Newark, New Jersey
Fire Hydrant
Service Leak at
House #195
Average Pipe Wall Thickness of
0.18”, 63.9% loss
Pit #1 Valve
Pit #2
Pit #3
32
32
Newark, New Jersey
This is the remaining
structural thickness!
Confidential
33
33
Other Examples:
•
•
•
•
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
34
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
35