Corrosion in new copper pipe

[auntybellum]

Hello,
I have been looking for instances of unexpected pinholes in new copper pipe. I have asked this before but we are up to our fifth leak.
Firstly, it is not flux. This is a traditional response from the plumbing community, but it isn't.
Secondly, it is not 'poor quality' copper or old copper from the 70's.
This is new from a top UK supplier.

I suspect that many pinholes are dismissed as 'flux' or 'poor copper' and simply replaced without realisation of the true root cause, and I suspect that the problem is going to become steadily worse as levels of phosphates are increased.

The EU Drinking Water Directive has mandated that ortho-phosphates be added to supplied water to reduce the level of lead pickup from old lead pipework. The levels were reduced even more in December 2013.

95% of UK water is now phosphate dosed.

However, this has had the effect, in borehole water areas of making the normal 'patina' that forms inside the copper pipe to be come friable and flake off exposing the 'naked copper' and corrosion quickly sets in (a matter of months or a couple of years from new). It is called Type 1 pitting.

A pinhole appears and water loss results.

I repeat that it is not flux and I am looking to hear of these 'unexplained' pinhole leaks please.

Many thanks.

 

[lame plumber]

are you on a private water supply, sometimes these sources are quite acidic and eat through copper, as do some areas in the country, I see a lot of immersions in cyls destroyed in a year or less in one area I work in, presumably down to the water.

 

[auntybellum]

It's Thames Water actually but the key is 'borehole water'. Most UK water comes from 'surface water' (rivers feeding reservoirs) and this contains organic material (despite the filtering). This 'protects' the copper (or rather the protective patina) from the phosphate. Borehole water is very pure and carries little organic material.

 

[auntybellum]

p.s. what you describe could well be this mode of corrosion, not acidity in the supply.

 

[PhoenixServices]

Had one instance in a barn conversion couple of pinhole leaks, not flux related.
Ended being a complete gut and start again on the insurance as wrecked all the studwalls and oak flooring

 

[lame plumber]

why ask the question if you know all the answers?

 

[ShaunCorbs]

remove all copper and install stainless steel pipework would be the best answer

 

[kozak1968]

How long has the pipework been installed?

 

[auntybellum]

I ask the question to try and determine how widespread this problem is.

I feel it is almost a "scandal" maybe, brewing. Pinhole leaks are usually dismissed as 'flux' by the plumber, the customer has no idea why the leak occurred and accept flux as the cause, the insurer pays up and thinks no more of it, the makers of copper are rarely involved, but want all to be quiet and meanwhile there will be an ever growing number of these leaks with no-one putting two and two together.

We had an off the record meeting with the copper suppliers and they said they get up to 40 a year and there is one area supplied by one borehole where they recommend plastic above the ground floor because they have had so many ceilings down.

 

[auntybellum]

The first pipe failed at 41 months service life. The suppliers said that was a bit unusual as this failure normally manifests itself within 36 months. They replaced the pipes and another has failed at 43 months service life.

 

[chris watkins]

remove all copper and install stainless steel pipework would be the best answer

Just like they have done in Scottish hospitals etc but this is due to the acidic soft water.

or use plastic pipe.

 

[chris watkins]

Do you know if the system was left for any length of time before you moved in ?

Problems can arise if the systems are filled with heater for testing etc then part drained or left for a time before being put into full operation.

 

[SimonG]

Plenty round our way. Kerching.

 

[auntybellum]

Can't be sure - maybe a few months in the first failure but we were in the house when the replacement was made and would have been in service immediately.

 

[lame plumber]

most installers know their area and would install pipework accordingly, seems yours didnt.