1. Leakage control in transmission pipelines

2. Assessing Leakage in Transmission Mains
Trunks Mains connect sources and distribution areas
To assess leakage in Transmission Mains (TM) it is necessary to measure flow in different cross sections
District Metered area principle can be applied to TM

3. Trunk Mains Leakage Detection
Trunk mains (transmission mains) often have:
Large diameters
Low pressure
Non homogeneous pipe wall material (reinforced concrete)
Few access points
Long distance
All these make normal acoustic leakage detection difficult and other techniques have been developed
These techniques are highly specialised and normally done by contractors

4. Leak Detection With Acoustic Correlator
• Accelerometer / hydrophones
• Access pits (preferably tappings) required every 300m
• Cheap outright purchase; large civil works cost
• Only finds leaks when all variables in their favour

5. In-pipe Acoustic Technology Sahara® system
A sensor head or probe is inserted into a pressurized transmission main through a 50mm diameter tapping point. The flow of water carries the probe through the pipe and leaks are located by analyzing the acoustic signals that are generated by leaks in the pipe wall or joints. Once a suspected leak has been located the probe can be stopped at the position of the leak. It is possible to survey 2 km per insertion.
Cable, acoustic sensor and parachute
Sahara system

6. Sahara®
Cable Winch:

7. Sahara®
Real Time Tracking:

8. Sahara® • Internal Corrosion • Liner loss or condition
Not just leak detection – CCTV also:
• Internal Corrosion
• Liner loss or condition
• Pipe or valve defects

9. SmartBall® Water Main Leak Detection
• Free swimming inline device
• Ideal for long runs of trunk mains
• Requires 100mm tappings for insertion or extraction
• Tracked above ground every 1-2km with receiving units
• All data is saved on the ball and processed off site

10. SmartBall®
Insertion:

11. SmartBall®
Tracking:

12. SmartBall®
Retrieval:

13. SmartBall® advantages
Following significant advantages can be seen relative to conventional correlator technology: 1. Large Diameter Pipe: Unlike conventional correlation methods, SmartBall can be used to detect leakage on large diameter pipe (>18” in diameter). 2. Pipe Material: SmartBall is not sensitive to pipeline material, as it is not dependant on the pipeline to transmit the acoustic energy to surface mounted sensors. 3. Leak Sensitivity: Due to SmartBall rolling past the leak, it has optimum acoustic sensitivity and can detect leaks smaller than two liters per minute (dependant of line pressure and ambient noise floor). 4. The SmartBall system does not require the pipeline to be decommissioned and it can survey long pipelines efficiently, accurately and cost effectively.

14. Application SAHARA • Shorter distances where laterals exist
• Existing tappings could be used
• Used to periodically monitor critical mains
• When accuracy is very important
SMARTBALL
• Long distances per insertion; up to 25km
• Doesn’t require tracking unless leaks are located
• Reservoir to reservoir

15. Disadvantages SAHARA and SMARTBALL High Cost
It’s necessary to commit the proprietary company for implementation

16. Other Technologies

17. Remote Field Transformer Coupling system (PPIC)
Information on the location, distribution and number of wire breaks anywhere along the length of PCP (prestressed concrete pipe).
Knowing the broken wires it is possible to perform selected rehabilitation of pipeline segments delaying pipe replacement

18. RFTC Operation
Remote Field Transformer Coupling technology functions much in the same way as a radio transmitter and receiver. The "transmitter" produces an electromagnetic field.
The prestressing wires in the pipe amplify the signal.
If there are broken pre-stressing wires, the signal does not come through cleanly and the "receiver" picks up static, or noise.

19. Internal equipment

20. External equipment
Advantage: no dewatering before inspection

21. Acoustic Emission Testing (AET)
When a pipe is subjected to an external stimulus (change in pressure, load, etc), localized sources trigger the release of energy, in the form of stress waves, which propagate to the surface and are recorded as acoustic emissions by sensors.
The stress which can negatively affects the efficiency of the water networks can be generated by different natural or environmental reasons: earthquakes, overfloods, landslides or rockbursts

24. AET applications
Distressed pipes to know which pipes are continuing to deteriorate and to give advance warning if failure is eminent;
Critical pipes to detect if there are any deteriorating pipes in locations where a failure would have catastrophic consequences;
Whole pipelines to determine if there are any pipes in the line that are deteriorating and which sections require further testing;
Construction zones to learn if the pipeline has been inadvertently damaged.