Detecting a water leak electronically ?

[N Cook]

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


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

 

[Ken Weitzel]

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


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

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...

http://irc.nrc-cnrc.gc.ca/leak/leakdetect.html

Take care.

Ken

 

[mike]

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

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

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

--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
..
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted 12" LCD for Compaq Armada 7770MT.
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

 

[Allodoxaphobia]

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

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

 

[N Cook]

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




--
Return address is VALID but some sites block emails
with links. Delete this sig when replying.
.
Wanted, PCMCIA SCSI Card for HP m820 CDRW.
FS 500MHz Tek DSOscilloscope TDS540 Make Offer
Wanted 12" LCD for Compaq Armada 7770MT.
Bunch of stuff For Sale and Wanted at the link below.
MAKE THE OBVIOUS CHANGES TO THE LINK
ht<removethis>tp://www.geocities.com/SiliconValley/Monitor/4710/

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
30 to 45 minutes at about -15 degree C.

 

[N Cook]

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

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

 

[Wayne Tiffany]

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

 

[N Cook]

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

Did that this pm.
Assorted readings mainly in hundreds of kilohms and one area showing about
500 ohms so dug down to the pipe and nothing found.

 

[**THE-RFI-EMI-GUY**]

Radioactive Isotope tracer?

Did that this pm.
Assorted readings mainly in hundreds of kilohms and one area showing about
500 ohms so dug down to the pipe and nothing found.

--
Joe Leikhim K4SAT
"The RFI-EMI-GUY"

The Lost Deep Thoughts By: Jack Handey
Before a mad scientist goes mad, there's probably a time
when he's only partially mad. And this is the time when he's
going to throw his best parties.

 

[Rheilly Phoull]

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


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

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).

 

[N Cook]

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

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.

 

[Michael Gray]

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


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

Have you considered using smoke to test for leaks?
http://www.hurcotech.com/

 

[N Cook]

Have you considered using smoke to test for leaks?
http://www.hurcotech.com/

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.

 

[Bill Jeffrey]

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

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

 

[Michael Gray]

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.

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.

 

[N Cook]

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.

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.

 

[quietguy]

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

 

[Asimov]

"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" <[email protected]>
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