Continuous Monitoring Leak Detection

[SAmecheng]

Does anyone have experience using continuous monitoring leak detection equipment in underground pipeline? If so, what/who do you recommend? Acoustic emissions, fiber optic sensing (vapor, liquid), etc...

Length: 1.3 miles
Product: Ethanol
Diameter: 8" underground
Max pres: 100 #

Thanks in advance.

 

[BigInch]

None of the above. Carefully record compensated measured volumes into the pipe minus measured compensated volumes out. Should work nicely, since the line is so short there won't be much packing errors due to long stretches where the pressure and temperature are not accurately known. If you must use one of the above, I would think probably accoustic monitoring would be the best choice, but I don't have experience in that.

http://virtualpipeline.spaces.msn.com

 

[Ashereng]

I don't have any experience using leak detection, but do have some experience looking into which technology to pursue.

One of the more "high tech" solution involved (I am going on memory here) acustics whereby a leak will send a sound wave up and down the pipe, and the system will detect these "peaks" and calculated the time differences, and determine where the leak is (to within something like 20 feet). This was particulary interesting to us at the time as our entire line was buried (about 200 km).



"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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[BigInch]

Ashereng, I've "heard" using acoustics that there can be trouble discriminating actual leak signals from other events. Do you know if there is any truth to that?

http://virtualpipeline.spaces.msn.com

 

[Ashereng]

I am sure there is some truths, especially earlier on when the technology first came out.

I looked into the technology about 5-6 years ago, and at that time, the "noise" and false signals were less of a concern than before. As with anything, there can be false "trips" due to unforseen situations. Overall, it is pretty good, especially for underground or "hidden" lines.

If you are interested, you should definitely talke to the vendors and see where the state of their offering is now.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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[dcasto]

From my own readings and tests (in 1994) acoustics looked promising, but I've not seen one in use. Pressure point analysis works better on long lines with multiple in/outs. For a short line, I'd have a SCADA system do a mass balance every minute. I'd also have rate of change alarms. Finally, you could set up a pressure drop table in the SCADA that said if the rate is X lb/hr the DP should be x psi. If it is less than x psi, alarm.

 

[Ashereng]

Also keep in mind that the acoustic people can provide location of leak, not just the fact that you have a leak.

"Do not worry about your problems with mathematics, I assure you mine are far greater."
Albert Einstein
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[stanweld]

Used AE over 25 years ago in a pressure test of about 12 miles of a gas pipeline. Located a leak quite brilliantly.