Acceptable leakage on water supply pipe?

[Ian H]

Is there such a thing?

I’m on a Severn Trent supplied house, the supply is 400mtrs long down a road before it gets to the house (which I don’t think is fair on the home owner but it is what it is).

Is was leaking 20l per hour. I dug at the new meter and found Severn Trents contractor hadn’t tightened one of their fittings. I tightened it and the leak has reduced to 1l every 64 minutes.

I feel like it’s a waste of my life to find such a small leak on such a long pipe. My boss says find it.

 

[Nige F]

But you're saving the planet, Ian Have you ever tried dowsing - seriously you never know

 

[Ian H]

Not on this job but I have tried it. I found a pipe on a farm, next job I tried it on I found nothing but rocks. I hired a 200mtr trace wire and I was about 60mtrs off the line of the pipe.

I can see how that could find the line of the pipe but not the leak itself??

 

[bernardgreen]

My boss says find it.

Then ask him to invest in a sonic leak detector system. ( though it might not work on a small leak if there is no noise generated at the site of the leak )

 

[Ian H]

A correlator? We tried one out but were not too keen on it.

 

[bernardgreen]

Yes one of them,

Or two microphones and a dual beam oscilloscope is the lower cost "DIY" option. Requires a bit of pen and paper calculation.

 

[KenGMac]

OK.

Totally in another direction.

My "hobby" is shooting, i shoot at targets.

The attached is a screen shot of target I was shooting at with a single shot 308 inch [7.62.mm] supersonic round

What is of interest here is that the target has several microphones around it they calculate where the bullet hits.

The attached was at 600 Yards, so called "open sights" not using a scope.

The second from center inner circle is about as large as a human head?

Best way to see this image is to right click and use the "save as" function then zoom in?

If electronics can hear and plot a bullet, OK traveling supersonic at a target there has to be something that can locate a leak ?

Ken

 

[dhutch]

400m long driveway? Or private road?

 

[Ian H]

A normal road, not even private. It’s the second one like that i’ve done this week.

I don’t know why Severn Trent aren’t digging at the property boundary like they would if your meter was 600mm off your boundary in the public footpath.

 

[Ian H]

I’m not sure the microphones would work Ken, there’s too much road noise.

 

[bernardgreen]

I’m not sure the microphones would work Ken, there’s too much road noise.

The output from the "microphones" is filtered to reject all but the hissing sound from the leak. The microphones are attached to the pipe and are insensitive to air born sounds.

 

[Ian H]

How much would I be looking at for a kit like that?

 

[YorkshireMidge]

I'm sure I've read somewhere that if it's feasible to shut off the supply and empty the pipe of most of the water, you can pump some sort of mix of gasses in - and then detect the gas where it works its way out - even through reasonably solid surfaces like tarmac. Sounds expensive to buy but might be possible to hire. Wouldn't be affected by background noise either, as it is detecting the gas, not the sound of it escaping.

 

[Ian H]

Yes, there is a gas test but I believe it’s no good on a long run but worth an ask.

I’m going to dig onto the pipe now, about 30mtrs down from the previous leak, cut and cap it and hope the leak still shows on the meter.

 

[bernardgreen]

How much would I be looking at for a kit like that

Google found several hire companies, https://www.inlec.com/seba-kmt-correlux-p-2-digital-correlator-and-xmic-water-leak-detection-kit being one at £315 per week hire.

It appears to use two microphones linked by wireless to the central computing unit so would probably be more expensive than a system using wires to the microphones.