Holed copper tube?

[Agile]

About a year ago I went to a gravity fed hot water system where the 5m section of 15 mm tube from the cylinder had a pinprick leak about 2 m before the kitchen hot tap.

I did the usual repair by fitting an 80 mm section of new tube using end feed couplings.

Now it has another leak exactly in the centre of my new piece of tube.

I have to say this is the first time that I have encountered something as odd as this and have never heard of it anywhere else either!

Can anyone else offer any suggestions why this could have happened?

Tony

 

[ree]

See: repairmyleak.com
the copper section.

In brief the best bet is to replace the 5m length of copper with plastic pipe of the next diameter up, ie. 22mm and inform the Utility.

 

[muggles]

Is it on a private supply?

 

[picasso]

Faulty immersion heater (earth leakage perhaps)?

 

[bernardgreen]

Pin prick holes in good quality copper pipe are very rare. So to get two in roughly the same place on both the original and the replacement pipe has to be a once in a life time event.

Or has someone had a bit of malicious fun with a small sharp object or drill.

Back in the early 1980's some imported copper tube ( Eastern European ? ) that had impurities in the copper. With water in the pipe some of these impurites eventually dissolved out or just fell out and created pin prick holes ( or larger ).

 

[Agile]

There is no electric current flowing in the copper pipe. The hot water cylinder is heated by the gas boiler.

Whilst I can accept that the original hole could have been due to faulty tube, as the new hole is in exactly the same position ( within 10 mm! ) then there is something VERY unusual involved here.

It may be a coincidence but the angle of the hole is the same too!

The water supply is from a communal loft tank which was replaced at the time I repaired the original leak. I had to come as the work was being done to install an isolating valve in the flat as previously there was no way to turn off the water.

Tony

 

[bernardgreen]

Electric current would only melt a hole if there was contact at the location of the hole. A massive current would be needed and the hole would be surrounded by scorched copper.

Do you have a photo of the hole ( either the original or preferably the latest and most mysterious one ) ?

Were there any signs of something having been pessed onto the pipe, a depression around the hole would indicate something being pressed into the pipe. Burrs around the hole could indicate a drill had been used.

Is there anything near the pipe that has a sharp point that could have been pushed ( very hard ) against the pipe.

It is not impossible this is a pure co-incidence but very very un-likely.

 

[Dan Robinson]

Perhaps aliens fell in?

 

[stardanny]

I had a job before replacing a few metres of 22mm which had lot of pinhole leaks.
The house was built in the 80's.
Perhaps a faulty batch of copper tubes got in the market.

Daniel.

 

[Agile]

The pipe is at ceiling level and it runs in the open with nothing touching it.

The occupiers have not touched it.

The actual hole is minute and the water mostly evaporates with only the occasional drip falling.

Tony

 

[Agile]

I had a job before replacing a few metres of 22mm which had lot of pinhole leaks.
The house was built in the 80's.
Perhaps a faulty batch of copper tubes got in the market.

Daniel.

The original pipe was probably from the 60s/70s but my replacement was current production!

 

[bernardgreen]

Are you sure you didn't put the dud bit of pipe back in. ( I have done that when repairing electronic equipment )

 

[Agile]

When soldering pipes I always use nice shiny new pipe as that saves me time and effort.

Quite apart from what a client would think if I used a bit of old pipe!

 

[bernardgreen]

I guessed that but I can't be the only absent minded one here ........

 

[oldbuffer]

Particles of steel from old mild steel pipes (or old cistern?) settling at low point in pipe causing galvanic action?