Finding a leak location - underground 4in utility line
Finding a leak location - underground 4in utility line
(OP)
Our 4" utility line has a bad leak.
Fluid: water
Pressure: 5 barg
Temperature: ambient (above 0 deg)
Pipe lenght: 800 m
Depth: 1 m, covered with 30 cm of concrete
The leak is quite bad indicating construction issue, and not corrosion. I am trying to understand capabilities of various inspection techniques to locate the leak. Pigging is not feasible. I have in mind either long range UT or eddy current testing.
Any advice on the most suitable technique, number of locations for excavation, etc. would be appreciated.
Fluid: water
Pressure: 5 barg
Temperature: ambient (above 0 deg)
Pipe lenght: 800 m
Depth: 1 m, covered with 30 cm of concrete
The leak is quite bad indicating construction issue, and not corrosion. I am trying to understand capabilities of various inspection techniques to locate the leak. Pigging is not feasible. I have in mind either long range UT or eddy current testing.
Any advice on the most suitable technique, number of locations for excavation, etc. would be appreciated.





RE: Finding a leak location - underground 4in utility line
There are acoustic systems about - search acoustic leak detection - which you dig down, expose the pipe at certain intervals (50m?) and then they listen for the leak sound and gradually narrow it down using stereo connections. - typical see http://ashtead-technology.com/productgroup/instrum...
The alternative is simply to dig down, break in and isolate at the 400m point, pressure up from one or both sides and find out which side the leak is, then half that distance and repeat and repeat until you identify a 15-20m lenght which you then just excavate the lot. A bit brutal, but effective. You don't say what the line is but if it is PE, then you can just squeeze it off to effect an isolation which it then recovers from.
If you have any fittings or connections on this line you could try those first.
Murphys law normally applies here which is that the leak will be in the worst possible location....
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Finding a leak location - underground 4in utility line
RE: Finding a leak location - underground 4in utility line
RE: Finding a leak location - underground 4in utility line
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Finding a leak location - underground 4in utility line
We have used acoustic vibration successfully over the length > 800m. The leak was identified with +/- 5m accuracy.
Thank you all!
RE: Finding a leak location - underground 4in utility line
RE: Finding a leak location - underground 4in utility line
Acoustic is good if you have a growing crack, but if you don't then that's pretty limited.