Does anyone know how this happens

[exedon2]

Not that uncommon see pinhole corrosion 2 or 3 times a year even had it on my own property!
Always understood it's part of manufacturing process copper tube is drawn out and has to be anealed every so many passes.
During this process very occasional a small piece is scale becomes embedded in internal tube wall . Tube is very thin at that point and hard water and as some stage small fountain!

 

[chris watkins]

Not that uncommon see pinhole corrosion 2 or 3 times a year even had it on my own property!
Always understood it's part of manufacturing process copper tube is drawn out and has to be anealed every so many passes.
During this process very occasional a small piece is scale becomes embedded in internal tube wall . Tube is very thin at that point and hard water and as some stage small fountain!

Not true I am afraid, at least it hasn't been for many a long year.
It is really worth the read, here is the link again http://www.fwr.org/copper.pdf
For the record it was type 2 (not 1) that I had a lot of problems with on high temp secondary HW returns.

 

[NickH]

Maybe I need to get out more but I found that very interesting. Lots that rings true and lots of things which I know a lot of us do are clearly not best practice.
Food for thought.

 

[chris watkins]

Maybe I need to get out more but I found that very interesting. Lots that rings true and lots of things which I know a lot of us do are clearly not best practice.
Food for thought.

I definitely need to get out more !!

 

[OffshoreGas]

Modern copper pipe from the big suppliers seems to have about 1/2 the wall thickness of the good old stuff you take out. Think we will be seeing a lot more of this stuff in years to come.

 

[Brambles]

I don’t think that is correct. It depends on wherther or not you are comparing current specification R250 or R290 copper tube with earlier specifications. I have just micrometered ( if that is a word ) pieces of 15mm copper from 1969, 1976 and a new piece of R290 from stock. The wall thicknesses are all within the band 0.7 to 1.1mm - admittedly only three samples, with the latter (1.1mm) being current material. R250 (half hard) would be 0.7mm plus or minus 10%

 

[OffshoreGas]

I don’t think that is correct. It depends on wherther or not you are comparing current specification R250 or R290 copper tube with earlier specifications. I have just micrometered ( if that is a word ) pieces of 15mm copper from 1969, 1976 and a new piece of R290 from stock. The wall thicknesses are all within the band 0.7 to 1.1mm - admittedly only three samples, with the latter (1.1mm) being current material. R250 (half hard) would be 0.7mm plus or minus 10%

It may be that its old imperial tube I've removed or that innner walls have an accumulation of contaminates but the old stuff seems to have significantly more heft than what I fit today. It could also be that I'm comparing with tube from the likes of Screwfix and not a merchant who may hold better quality products. Your analyasis is much more scientific than my entirely gut based approach so I could well be wrong.

 

[Chuck]

15mm is available in wall thicknesses that range from 0.5 mm to 1.5mm.
Retail stores tend to stock relatively thin-wall, types, typically 0.7mm or 0.8mm.

Specifying copper tube correctly is surprisingly complicated:

https://copperplumbing.org.uk/sites/default/files/content_attachments/en-standards_0.pdf

 

[OffshoreGas]

15mm is available in wall thicknesses that range from 0.5 mm to 1.5mm.
Retail stores tend to stock relatively thin-wall, types, typically 0.7mm or 0.8mm.

Specifying copper tube correctly is surprisingly complicated:

https://copperplumbing.org.uk/sites/default/files/content_attachments/en-standards_0.pdf

Thanks for the info, I've seen similar specs in industrial applications but never for domestic stuff. Interesting to know, I guess its the race to the bottom like everything else.

 

[Mdljk]

Shaun Cobbs has a point as excess flux can slowly rot a pipe from inside.

 

[OffshoreGas]

Shaun Cobbs has a point as excess flux can slowly rot a pipe from inside.

Could be one of 1000 factors or more likely a combination of them. Manufacturing defect, damage during installation, a small piece of dissimilar meter detached from a valve or fitting upstream, turbulent flow/cavitation, excessive flow due to to higher pump speed, the presence of flux etc. Hard to know what the actual cause is with something like this.

 

[centralheatking]

The best tube and fittings are medical standard , we used them years ago when we did medi gas.in hospitals ...oxy and vac
then we did some hydrogen in certified labs and nitrogen to cool down laser things ..awesome quality
centralheatking

 

[Stigster]

Shaun Cobbs has a point as excess flux can slowly rot a pipe from inside.

Along with overtightening compression fittings, people using excess flux really gets on my nerves like very few other things do, almost irrationally so it seems! There's just no need for it. It runs down the outside of the pipe, often past where you end up cleaning after soldering, it runs down inside the pipe and can cause "occlusion corrosion" and great blobs of it can get baked on inside the fittings again causing occlusion. I follow the WRAS guidelines and never flux the fitting either as it isn't helping anything. Even for those that do clean the pipe they were working on properly after soldering, I've seen people have excess flux drip all down over any pipework clipped in below which they usually fail to notice and clean.

STOP IT! ;-)

I do a demo in the workshop where I show just how little flux can actually be used, purely to make a point, not as good practice. I clean the pipe with cleaning strip enthusiastically, apply La-Co flux, wipe the flux away with a clean cloth and can still make the joint properly. In practice a little more flux than that is required but it does show the pointlessness of using tons of the stuff.

/rant

 

[Excite]

Yes...looks like excess flux

 

[Mdljk]

Could it be uncleared flux?

This gets my vote as a likely reason. Excess flux used on nearby fitting can settle onto interior surface of pipe and over the course of time the acid in the flux can corrode the pipe from the inside creating a pinhole.

 

[WC1]

I've often thought any tiny flake of steel or other metal coming off the tooling in the factory would do a good job of pinholing the tube after a few years.