Detecting a water leak electronically ?

Hi...

Suspect that not much is going to help other than bracketing sections of the pipe and listening for vibration, but this might make for helpful reading...

Take care.

Ken

I'd like to hear more about the freezing technique for locating leaks. HOw do you get water ice to freeze the pipe, especially when there's at least 3 gal/hr moving thru it??

Ultrasonic leak detectors work well on gas leaks. Expect you'd have the same "anywhere" problem on pipe tho. Just too much sound conductivity. mike

Are you certain that there is no "T" junction on the pie, and that the 'outflow' isn't off at dsome distance?

I've seen instances where a homeowner has the city shut off the water service coming into the house (out at the street) (to do some major interior re-plumbing) -- only to have the neighbours complain that _they_ have no water. (This in a community that used "Flat Rate" water billing.) It was one service pipe coming from the street, with a "T" installed somewhere inside the property line, and a second pipe running to the other, later-built house.

So, some long forgotten re-work on that line could be the problem. Especially if it was a Rube Goldberg Job with sub-standard materials and/or workmanship.

HTH Jonesy

run

From crushed ice from freezer and cooking salt about 500 g to 0.5 Lt made up freezing solution and placed in plastic trough. Monitoring with thermometer the pipe froze up in about

run

Unlikely as consistently the leak is 0.26 +- 0.02 Lt per minute day or night

-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on

What about pushing rods into the ground and measuring the resistance between them, or something like that. The idea being that the wet ground will conduct much better.

WT

between

run

Did that this pm. Assorted readings mainly in hundreds of kilohms and one area showing about

Sounds like you are spending a lot of time on it, why not cut the losses and call in someone with the specialised instrument. They can pinpoint a leak fairly quickly (15min or less).

between

run

There's only one (very dry ) section left , under the external door. I suspect there must be a 'T' there running off to anybody's guess where but otherwise redundent and a leak along there or perhaps just folded over end rather than capped off.

Have you considered using smoke to test for leaks?

run

I did consider digging out an air pump , turning off the supply at the pavement and blowing air back into the piping to see if it would whistle where the leak is.

Good idea. Can the suspect section of the pipe be sealed off, dried out, and put under air pressure? In the US, anyway, standard fittings for pressurizing water pipe are available at Home Depot etc (you have an equivalent in the UK). They are used by both water-plumbers and gas-plumbers to insure pipe integrity. Go into any new-construction house where the plumbing has been roughed out ...

Of course, as someone else noted, this is all getting more elaborate than it may be worth.

Bill

Listening for potentially non-existent whistles, is about 90% less reliable than looking for smoke. Plumbers often put peppermint essence in smoke, so that if it can't be seen, there is a very good chance it can be smelled.

Plumbers have been using this method for hundreds of years, and have yet to change it, for the good reason that it works. And it's cheap.

Why re-invent the wheel? Your local plumbing supplier should have smoke bombs for this very purpose.

steel

I will look into that as interesting solution , although not this time as I've traced the leak but such a system would have avoided a couple of excavations.

Depending on how deep your pipe is, one of those garden moisture meters might help - either just shoeve it into the soil and look for the point at which moisture is max, or use a post hole digger (2inch) to do holes every foot of so in the suspect area and measure soil moisture - might work.

David

N Cook wrote:

"N Cook" bravely wrote to "All" (16 Sep 05 11:37:48) --- on the heady topic of "Detecting a water leak electronically ?"

NC> From: "N Cook" NC> Xref: core-easynews sci.electronics.repair:342275

NC> By excavating pits and freezing the pipe I localised down to a 20 foot NC> run and then a 10 foot run. I've now dug 2 more pits so about 3 foot NC> apart in that 10 foot. 3 gallons of water an hour is just disappearing NC> with no trace emerging along pipe or into holes.

NC> While I wait for more water to freeze in the freezer to NC> localise a bit more, anyone any ideas for electronically/ NC> audibly trying to localise the leak. A listening stick made from a NC> steel rod and a wooden drawer knob certainly works against anywhere NC> on the pipe (thats the problem ,anywhere , NC> and much same level) but nothing through the soil

I would try something like using 2 cheap electret (or piezo disk) elements stuck onto the end of a couple of rods and listening to the amplified signal through stereo headphones. In theory the idea would be to adjust the balance with a known tone to give an equal output, then push the rods into the ground and listen to any difference. This being based on the principle that the brain descriminates stereo localization better than any instrument. Just an idea...

A*s*i*m*o*v

... That was a fascinating period of time for electronics