I've traced the pipe run by injecting a signal into the pipework
and tracing with a small pocket size short wave receiver.
Easy access, under liftable floor boards,  to the pipe run in the middle of
the house, with
pavement stopcock open I can hear a leak via a piece of broom handle
and with company stop cock off there is no leak hiss noise.
With kitchen isolator off and pavement one on there is a hiss.
No obvious damp in that area of the house.
Assuming I successfully freeze the pipe and water in the middle I
can then determine which side of that mid point. One end is in garden soil
and the other under concrete of the kitchen floor , under there somewhere
is a conversion from lead pipe to copper pipe, likely problem point ?.

Any ideas?.  Would a microphone and silicon grease to the concrete floor
or metal plate rammed in the soil pick up enough sound when put through
an amplifier be able to zero in ?

N Cook wrote:

> I've traced the pipe run by injecting a signal into the pipework
> and tracing with a small pocket size short wave receiver.
> Easy access, under liftable floor boards,  to the pipe run in the
> middle of the house, with
> pavement stopcock open I can hear a leak via a piece of broom handle
> and with company stop cock off there is no leak hiss noise.
> With kitchen isolator off and pavement one on there is a hiss.
> No obvious damp in that area of the house.
> Assuming I successfully freeze the pipe and water in the middle I
> can then determine which side of that mid point. One end is in garden
> soil and the other under concrete of the kitchen floor , under there
> somewhere is a conversion from lead pipe to copper pipe, likely
> problem point ?.
>
> Any ideas?.  Would a microphone and silicon grease to the concrete
> floor or metal plate rammed in the soil pick up enough sound when put
> through
> an amplifier be able to zero in ?


You want to watch that, I hear the water board listen in on shortwave radio
for any would be DIY'ers messing about with their pipes.

On Sun, 11 Sep 2005 13:11:48 +0100, "N Cook"  wrote:

| I've traced the pipe run by injecting a signal into the pipework
| and tracing with a small pocket size short wave receiver.
| Easy access, under liftable floor boards,  to the pipe run in the middle of
| the house, with
| pavement stopcock open I can hear a leak via a piece of broom handle
| and with company stop cock off there is no leak hiss noise.
| With kitchen isolator off and pavement one on there is a hiss.
| No obvious damp in that area of the house.
| Assuming I successfully freeze the pipe and water in the middle I
| can then determine which side of that mid point. One end is in garden soil
| and the other under concrete of the kitchen floor , under there somewhere
| is a conversion from lead pipe to copper pipe, likely problem point ?.

Yes worth looking at.
 
| Any ideas?.  Would a microphone and silicon grease to the concrete floor
| or metal plate rammed in the soil pick up enough sound when put through
| an amplifier be able to zero in ?

All tool hire places have pipe finders, which are better than metal
detectors, because they will detect electric cables as different from water
pipes.   A bit pricey.

It is also worthwhile considering replacing the lead with copper, because
lead in drinking water is a *bad* thing.
-- 
Dave Fawthrop <dave hyphenologist co uk> 
"Intelligent Design?" my knees say *not*.
"Intelligent Design?" my back says *not*.

In article <dg16ov$451$1@inews.gazeta.pl>,
	"N Cook"  writes:

>
>Any ideas?.  Would a microphone and silicon grease to the concrete floor
>or metal plate rammed in the soil pick up enough sound when put through
>an amplifier be able to zero in ?


Water companies do something a bit like this.

Using a mic attached to each end of the pipe (i.e. the two
stopcocks in your case), connect each to the input of a dual
trace scope. Now if you tap the pipe at one end, you'll see
the pulse instantly at that mic, and delayed at the other mic.
(You might also see other reflections from where the pipe
joins the mains, and the like.)
Similarly, if you tap the pipe at the other end, you'll see
the same but the other way around. Ideally, adjust the time
base and trigger so these two pulses are separated by about
2/3rds of a single sweep of the timebase, i.e. the timebase
represents just a bit more than the time taken for the sound
to travel the length of the pipe between the stopcocks.

If you turn up the gain, you should see the pink noise
generated by the leak on the two traces. Now if the leak is
at one of the stopcocks (very common in the case of the
outdoor one), you will see the pink noise is shifted between
the two traces, with the gap being the same as when you tapped
on the pipe before and with the mic on the outside stopcock
showing the data earlier. Conversely, if the leak is in the
middle of the pipe, you will see the leak (pink noise) is
completely lined up between the two traces. For other leak
positions between the middle and end of the pipe, the
shift will be proportional, and the mic showing it first
will indicate which side of the middle of the pipe it is.

This is all well and good in theory, but matching up two
pink noise traces may not be easy. I rather suspect the
water company equipment does this by computer. This also
assumes constant sound velocity in the pipe, which might
not be the case if there's a join with different types of
pipe either side of it.
And no, I haven't tried doing this for real...

-- 
Andrew Gabriel

"Andrew Gabriel"  wrote in message
news:43242df5$0$38038$5a6aecb4@news.aaisp.net.uk...

> In article <dg16ov$451$1@inews.gazeta.pl>,
> "N Cook"  writes:
> >
> >Any ideas?.  Would a microphone and silicon grease to the concrete floor
> >or metal plate rammed in the soil pick up enough sound when put through
> >an amplifier be able to zero in ?
>
> Water companies do something a bit like this.
>
> Using a mic attached to each end of the pipe (i.e. the two
> stopcocks in your case), connect each to the input of a dual
> trace scope. Now if you tap the pipe at one end, you'll see
> the pulse instantly at that mic, and delayed at the other mic.
> (You might also see other reflections from where the pipe
> joins the mains, and the like.)
> Similarly, if you tap the pipe at the other end, you'll see
> the same but the other way around. Ideally, adjust the time
> base and trigger so these two pulses are separated by about
> 2/3rds of a single sweep of the timebase, i.e. the timebase
> represents just a bit more than the time taken for the sound
> to travel the length of the pipe between the stopcocks.
>
> If you turn up the gain, you should see the pink noise
> generated by the leak on the two traces. Now if the leak is
> at one of the stopcocks (very common in the case of the
> outdoor one), you will see the pink noise is shifted between
> the two traces, with the gap being the same as when you tapped
> on the pipe before and with the mic on the outside stopcock
> showing the data earlier. Conversely, if the leak is in the
> middle of the pipe, you will see the leak (pink noise) is
> completely lined up between the two traces. For other leak
> positions between the middle and end of the pipe, the
> shift will be proportional, and the mic showing it first
> will indicate which side of the middle of the pipe it is.
>
> This is all well and good in theory, but matching up two
> pink noise traces may not be easy. I rather suspect the
> water company equipment does this by computer. This also
> assumes constant sound velocity in the pipe, which might
> not be the case if there's a join with different types of
> pipe either side of it.
> And no, I haven't tried doing this for real...
>
> --
> Andrew Gabriel
>


Just as well I'm an electronic engineer and understand what you
say. I would probably take the T/B trig-out signal, buffer and repeatedly
trip a small solenoid
to tap the pipe.
I now know the pipe run goes copper from company stop
cock to just inside the house, perfectly good sweated joint there.
Then the original and good lead run up to somewhere under concrete where
there must be another such conversion.
I've bunged some water in the freezer and with that broken up
and packed around the pipe along with maybe some freezer spray
I know I can freeze the water (as I've done this before to repair a pipe
where it was
not possible to fully turn off the mains supply ) to narrow down which end
is the problem.
Then unusually try the mike and 2 channel scope thing - very rare that I use
both
channels of a scope. Listening on the broom handle the noise seems louder
at the garden end rathe rthan concrete covered end but that may be due to
unconstrained pipe there so can resonate freer.

Should it be a leak in the lead run I know the following technique works
and I even placed on my otherwise electronic repair/tips files. I had to
repair a lead pipe at the bottomost part of its run where it had chafed
on the edge of a brick so the sweating was on the underside of the pipe
so worst possible situation.

"repairing holes in old lead water pipe - use 2 hot air guns,one to
dry out enclosed water and generally heat the pipe and the other one to
locally heat to sweat
in lead solder. Even a novice can do a functional repair like this as there
is much less chance of
the pipe totally melting away as with blow-lamp heating."
on
http://www.divdev.fsnet.co.uk/tips2.htm

In article <dg16ov$451$1@inews.gazeta.pl>, diverse@tcp.co.uk says...

> I've traced the pipe run by injecting a signal into the pipework
> and tracing with a small pocket size short wave receiver.
> Easy access, under liftable floor boards,  to the pipe run in the middle of
> the house, with
> pavement stopcock open I can hear a leak via a piece of broom handle
> and with company stop cock off there is no leak hiss noise.
> With kitchen isolator off and pavement one on there is a hiss.
> No obvious damp in that area of the house.
> Assuming I successfully freeze the pipe and water in the middle I
> can then determine which side of that mid point. One end is in garden soil
> and the other under concrete of the kitchen floor , under there somewhere
> is a conversion from lead pipe to copper pipe, likely problem point ?.
> 

More likely the copper hasn't been isolated from the concrete and it's 
corroded, in which case you want to rip the whole lot out anyway.

In article <dg16ov$451$1@inews.gazeta.pl>,
   N Cook  wrote:

> One end is in garden soil and the other under concrete of the kitchen
> floor , under there somewhere is a conversion from lead pipe to copper
> pipe, likely problem point ?.


It would be a very foolish thing to wipe a lead to copper joint then lay a
concrete floor over it.

-- 
*Middle age is when it takes longer to rest than to get tired.

    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

"Andrew Gabriel"  wrote in message
news:43242df5$0$38038$5a6aecb4@news.aaisp.net.uk...

> In article <dg16ov$451$1@inews.gazeta.pl>,
> "N Cook"  writes:
> >
> >Any ideas?.  Would a microphone and silicon grease to the concrete floor
> >or metal plate rammed in the soil pick up enough sound when put through
> >an amplifier be able to zero in ?
>
> Water companies do something a bit like this.
>
> Using a mic attached to each end of the pipe (i.e. the two
> stopcocks in your case), connect each to the input of a dual
> trace scope. Now if you tap the pipe at one end, you'll see
> the pulse instantly at that mic, and delayed at the other mic.
> (You might also see other reflections from where the pipe
> joins the mains, and the like.)
> Similarly, if you tap the pipe at the other end, you'll see
> the same but the other way around. Ideally, adjust the time
> base and trigger so these two pulses are separated by about
> 2/3rds of a single sweep of the timebase, i.e. the timebase
> represents just a bit more than the time taken for the sound
> to travel the length of the pipe between the stopcocks.
>
> If you turn up the gain, you should see the pink noise
> generated by the leak on the two traces. Now if the leak is
> at one of the stopcocks (very common in the case of the
> outdoor one), you will see the pink noise is shifted between
> the two traces, with the gap being the same as when you tapped
> on the pipe before and with the mic on the outside stopcock
> showing the data earlier. Conversely, if the leak is in the
> middle of the pipe, you will see the leak (pink noise) is
> completely lined up between the two traces. For other leak
> positions between the middle and end of the pipe, the
> shift will be proportional, and the mic showing it first
> will indicate which side of the middle of the pipe it is.
>
> This is all well and good in theory, but matching up two
> pink noise traces may not be easy. I rather suspect the
> water company equipment does this by computer. This also
> assumes constant sound velocity in the pipe, which might
> not be the case if there's a join with different types of
> pipe either side of it.
> And no, I haven't tried doing this for real...
>
> --
> Andrew Gabriel
>


One of the odd bits of test equipment I have is a stethoscope for trying to
locate the source of squeaks in mechanical equipment.
I tried going over the concrete floor every foot of run listening for any
noise but nothing heard,
also tried with a metal rod with a wooden
cupboard knob on the end instead of broom handle as a listening stick ,
better response
actually on the pipe but nothing heard thru' concrete.

I won't be doing the same with stethoscope, in daylight anyway, over
the garden unless freezing halfway shows it is definitely at that end.

N Cook  wrote:

> "Andrew Gabriel"  wrote in message
> news:43242df5$0$38038$5a6aecb4@news.aaisp.net.uk...
>> In article <dg16ov$451$1@inews.gazeta.pl>,
>> "N Cook"  writes:
>> >
>> >Any ideas?.  Would a microphone and silicon grease to the concrete floor
>> >or metal plate rammed in the soil pick up enough sound when put through
>> >an amplifier be able to zero in ?
>>
>> Water companies do something a bit like this.
>>
>> Using a mic attached to each end of the pipe (i.e. the two
>> stopcocks in your case), connect each to the input of a dual
<snip>
> Just as well I'm an electronic engineer and understand what you
> say. I would probably take the T/B trig-out signal, buffer and repeatedly
> trip a small solenoid


Hmm.
Me, I suspect I'd try using a computer with a couple of mics inputting to
left and right channels.
Then do a trivial app to take the wav file, and spit out a text file for
plotting with gnuplot.

That is a handy technique.

On Sun, 11 Sep 2005 13:11:48 +0100, N Cook wrote:


> I've traced the pipe run by injecting a signal into the pipework
> and tracing with a small pocket size short wave receiver.
> Easy access, under liftable floor boards,  to the pipe run in the middle of
> the house, with
> pavement stopcock open I can hear a leak via a piece of broom handle
> and with company stop cock off there is no leak hiss noise.
> With kitchen isolator off and pavement one on there is a hiss.
> No obvious damp in that area of the house.
> Assuming I successfully freeze the pipe and water in the middle I
> can then determine which side of that mid point. One end is in garden soil
> and the other under concrete of the kitchen floor , under there somewhere
> is a conversion from lead pipe to copper pipe, likely problem point ?.
> 
> Any ideas?.  Would a microphone and silicon grease to the concrete floor
> or metal plate rammed in the soil pick up enough sound when put through
> an amplifier be able to zero in ?


The low tech approach which has worked for me both underground,
under-floor in concrete leaks, and dmapness in general:

Find the boundary of approximately equal wetness  (or dampness) go for the
middle. This works because the soil or the concrete or whatever are
reasonably consistent in the way water travels.



-- 
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at http://www.diyfaq.org.uk 
Gas fitting FAQ  http://www.makewrite.demon.co.uk/GasFitting.html
Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html

"Ed Sirett"  wrote in message
news:pan.2005.09.11.20.41.45.600168@makewrite.demon.co.uk...

> On Sun, 11 Sep 2005 13:11:48 +0100, N Cook wrote:
>
> > I've traced the pipe run by injecting a signal into the pipework
> > and tracing with a small pocket size short wave receiver.
> > Easy access, under liftable floor boards,  to the pipe run in the middle
of
> > the house, with
> > pavement stopcock open I can hear a leak via a piece of broom handle
> > and with company stop cock off there is no leak hiss noise.
> > With kitchen isolator off and pavement one on there is a hiss.
> > No obvious damp in that area of the house.
> > Assuming I successfully freeze the pipe and water in the middle I
> > can then determine which side of that mid point. One end is in garden
soil
> > and the other under concrete of the kitchen floor , under there
somewhere
> > is a conversion from lead pipe to copper pipe, likely problem point ?.
> >
> > Any ideas?.  Would a microphone and silicon grease to the concrete floor
> > or metal plate rammed in the soil pick up enough sound when put through
> > an amplifier be able to zero in ?
>
> The low tech approach which has worked for me both underground,
> under-floor in concrete leaks, and dmapness in general:
>
> Find the boundary of approximately equal wetness  (or dampness) go for the
> middle. This works because the soil or the concrete or whatever are
> reasonably consistent in the way water travels.
>
>
>
> --
> Ed Sirett - Property maintainer and registered gas fitter.
> The FAQ for uk.diy is at http://www.diyfaq.org.uk
> Gas fitting FAQ  http://www.makewrite.demon.co.uk/GasFitting.html
> Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
>
>


Snap
This afternoon i  looked out a protimeter masonry probe, minus the meter but
I can use just a DVM instead for relative measurements. Will try tomorrow
after the mid point freezing

In message <dg16ov$451$1@inews.gazeta.pl>, N Cook  
writes

>I've traced the pipe run by injecting a signal into the pipework
>and tracing with a small pocket size short wave receiver.
>Easy access, under liftable floor boards,  to the pipe run in the middle of
>the house, with
>pavement stopcock open I can hear a leak via a piece of broom handle
>and with company stop cock off there is no leak hiss noise.
>With kitchen isolator off and pavement one on there is a hiss.
>No obvious damp in that area of the house.
>Assuming I successfully freeze the pipe and water in the middle I
>can then determine which side of that mid point. One end is in garden soil
>and the other under concrete of the kitchen floor , under there somewhere
>is a conversion from lead pipe to copper pipe, likely problem point ?.
>
>Any ideas?.  Would a microphone and silicon grease to the concrete floor
>or metal plate rammed in the soil pick up enough sound when put through
>an amplifier be able to zero in ?
>

There's a man in the states who reckons he has a pig that can do that

-- 
geoff

> under there somewhere is a conversion from lead pipe to copper pipe,
> likely problem point ?.


With buried unprotected copper and lead, I'd just abandon the whole lot and
replace the entire run with 25mm+ MDPE from stopcock to stopcock.

Christian.

The leak was 0.00026 L / min berfore icing up at inlet to house
and 0.00026 after icing up
so the leak (or maybe the major leak) is in the garden somewhere.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

"N Cook"  wrote in message
news:dg26du$dr3$1@inews.gazeta.pl...

>
> "Ed Sirett"  wrote in message
> news:pan.2005.09.11.20.41.45.600168@makewrite.demon.co.uk...
> > On Sun, 11 Sep 2005 13:11:48 +0100, N Cook wrote:
> >
> > > I've traced the pipe run by injecting a signal into the pipework
> > > and tracing with a small pocket size short wave receiver.
> > > Easy access, under liftable floor boards,  to the pipe run in the
middle
> of
> > > the house, with
> > > pavement stopcock open I can hear a leak via a piece of broom handle
> > > and with company stop cock off there is no leak hiss noise.
> > > With kitchen isolator off and pavement one on there is a hiss.
> > > No obvious damp in that area of the house.
> > > Assuming I successfully freeze the pipe and water in the middle I
> > > can then determine which side of that mid point. One end is in garden
> soil
> > > and the other under concrete of the kitchen floor , under there
> somewhere
> > > is a conversion from lead pipe to copper pipe, likely problem point ?.
> > >
> > > Any ideas?.  Would a microphone and silicon grease to the concrete
floor
> > > or metal plate rammed in the soil pick up enough sound when put
through
> > > an amplifier be able to zero in ?
> >
> > The low tech approach which has worked for me both underground,
> > under-floor in concrete leaks, and dmapness in general:
> >
> > Find the boundary of approximately equal wetness  (or dampness) go for
the
> > middle. This works because the soil or the concrete or whatever are
> > reasonably consistent in the way water travels.
> >
> >
> >
> > --
> > Ed Sirett - Property maintainer and registered gas fitter.
> > The FAQ for uk.diy is at http://www.diyfaq.org.uk
> > Gas fitting FAQ  http://www.makewrite.demon.co.uk/GasFitting.html
> > Sealed CH FAQ http://www.makewrite.demon.co.uk/SealedCH.html
> >
> >
>
> Snap
> This afternoon i  looked out a protimeter masonry probe, minus the meter
but
> I can use just a DVM instead for relative measurements. Will try tomorrow
> after the mid point freezing
>
>


The leak was 0.00026 L / min berfore icing up at inlet to  house
and 0.00026 after icing up
so the leak (or major leak) is in the garden.

N Cook wrote:

> The leak was 0.00026 L / min berfore icing up at inlet to house
> and 0.00026 after icing up
> so the leak (or maybe the major leak) is in the garden somewhere.


Hmmm. That's about the size of leak I had when they kindly installed my
meter with the wrong size fitting. Did this leak come with the meter,
or has it just started?

Chris

On Tue, 13 Sep 2005 19:43:28 +0100, "N Cook"  wrote:

| The leak was 0.00026 L / min berfore icing up at inlet to house
| and 0.00026 after icing up
| so the leak (or maybe the major leak) is in the garden somewhere.

Is there somewhere on the line where the plants grow *very* well and
everything is very green in a drought.?

-- 
Dave Fawthrop <dave hyphenologist co uk> 
"Intelligent Design?" my knees say *not*.
"Intelligent Design?" my back says *not*.

In message <dg76f0$9rs$1@inews.gazeta.pl>, N Cook  
writes

>The leak was 0.00026 L / min berfore icing up at inlet to house
>and 0.00026 after icing up
>so the leak (or maybe the major leak) is in the garden somewhere.
>

Was that averaged over a few days or do you have some incredibly 
accurate measuring equipment
-- 
geoff

In message , Dave Fawthrop 
 writes

>On Tue, 13 Sep 2005 19:43:28 +0100, "N Cook"  wrote:
>
>| The leak was 0.00026 L / min berfore icing up at inlet to house
>| and 0.00026 after icing up
>| so the leak (or maybe the major leak) is in the garden somewhere.
>
>Is there somewhere on the line where the plants grow *very* well and
>everything is very green in a drought.?
>

I wouldn't have thought that 1/3l/day would have that much of an effect

-- 
geoff

"raden"  wrote in message
news:Iz+ZQuLHrzJDFwth@ntlworld.com...

> In message <dg76f0$9rs$1@inews.gazeta.pl>, N Cook 
> writes
> >The leak was 0.00026 L / min berfore icing up at inlet to house
> >and 0.00026 after icing up
> >so the leak (or maybe the major leak) is in the garden somewhere.
> >
> Was that averaged over a few days or do you have some incredibly
> accurate measuring equipment
> --
> geoff


Whoops , the units are cubic metres not litres so x1000 for litres.
Looking at the pre-installation sheet , numerous tick boxes the
one marked leak was ticked which at the time I assumed it meant
ticked for having checked OK for leaking. Now with hindsight
it presumably meant it was leaking , by noise listening preumably , with the
unmetered
set-up, I was not there when they did that check.

On 13 Sep,  
     "N Cook"  wrote:


> The leak was 0.00026 L / min berfore icing up at inlet to house
> and 0.00026 after icing up
> so the leak (or maybe the major leak) is in the garden somewhere.


About 9  gallons a quarter, hardly a major leak, one flush of the bog.

-- 
  B Thumbs
  Change lycos to yahoo to reply

For the archives copied this reply across from posting on another forum.

On Sat, 17 Sep 2005 14:39:52 +0100, "N Cook" 
wrote:


>
>"Michael Gray"  wrote in message
>news:71kni1h2jv04vflc0id9avq1ta0i3gcmat@4ax.com...
>> On Fri, 16 Sep 2005 11:37:48 +0100, "N Cook" 
>> wrote:
>>
>> >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/
>
>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.