Tracing Leaks in Water Pipelines Passing Through Water Bodies?

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Hi All,

Apart from using Fluorescein dye to trace leaks in municipal water pipelines passing through water bodies, which other effective means can one use to trace leaks in such water pipelines?

Thanks

Justin

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10 Answers

  1. Agree with compressed air approach if pipe leak is underwater,  Acoustic Correlation would put you in the neighborhood, though measuring might be tricky.  You should be thinking about the repair at the same time as location.  For instance, if the repair is to slip line the pipe, exact location may not be critical.   But if you want to build a coffer dam to access the site, location, including depth will be vital. 

  2. It is often useful to use products being added to the water during treatment (if it has taken place). If you are adding chlorine or flouride, these are really good indicators of a leak, as they are usually below detection in lakes.

  4. Provided the section of affected pipe can be isolated temporarily, just simply apply a reasonable volume of compressed air (pressure subject to the grade of the pipe) and you will detect the location of the leak almost instantly.  It ain't rocket science! Depending on the type and size of the leak location, utilize a saddle clamp device that means you don't need to cut the pipe for repairs.

    Of course if the rupture is a split than can extend under pressure then cut and shut with gibault's would be recommended as a suitable repair mechanism. 

  5. Most leaks on pressurized pipe can be located acoustically. A typical leak noise correlator could locate the leak. With microphones it would work for a shorter distance between sensors like up to 1500' for metal pipe, or about 200' for plastic which would limit you to ponds or river crossings. For longer distances you can correlate with hydrophones sometimes thousands of feet or more.

    If you can turn off the water flow, tracergas would work. The Sewerin VT460 unit uses a hydrogen/nitrogen gas mix injected into the pipe. A gas sniffer then detects the hydrogen molecules directly above the leak.

     

  6. Hi Justin,

    I just want to give some insight on detecting water pipeline leak using physical properties of water. If you can isolate the pipeline, you can use metering zone to compare the volume differences between inlet-outlet which is considered as leak and pressure differences (seek for pressure drop) as Tim Acland mentioned earlier. Here you can use telemetry infrastructure such as data loggers.

    Another approach is to do step test and midnight flow analysis where you isolate and close the outlet and see if there is any flow detected (you can use portable clamped-on flowmeter if you have no flowmeter installed on the field). If a flow exists, you can later use portable leak detector and trace the leak through the pipeline to find the leakage point.

    Hope this help.

     

    1 Comment

  7. Hi Justin, it depends on many factors: length, depth, material, Water Quality (both municipal and water body), access, supply interruption, etc.… Techniques for you to consider are: diver, salt/helium/sulphur hexafluoride - tracers, leak noise correlation, JD7/Sahara, etc. etc.

  8. Use lithium chloride its a rare earth. Can analyse to ppb. Li trace. Very accurate.

  10. Hi Justin. You can consider use of tracer chemicals (even chlorine) then sample the pipe route. The dilution effect will indicate the size of any leak. However the chemicals must be considered very carefully. If the pipe can be drained then use pressurised air and look for the bubbles. If it cannot be isolated then consider using helium mixed into the water. For permanent monitoring why not install high accuracy meters at either end and monitor the difference. Pressure monitoring may be used as well.