Different types of copper boiler tube

I know ive read it before, but can someone remind me of why we ought not to use B&Q copper pipe in our boilers?

Some plumbing copper has lead in it so won't solder well, Have a look at "parent material" on Cup's Site

I have no idea what is in modern copper pipe, but I do know it is rubbish. My water supply is from my well and has high levels of iron and other stuff, modern copper just dissolves .3 or 4 years for a hot water pipe at best. Some pipes are old reclaimed copper and have no problems in 20 years. I do know some of this is because the new stuff is much thinner gauge but there must be some alloying in there to cause the rapid loss.

Modern water pipes - Ha!, you should have bought the French stuff that was sold in the 70's when Wednesburys were on strike, it pin holed in about 5 years, good for plumbers bad for DIYers. I bet it has all been replaced by now.. Why not try a cathodic protection lump as used on boats, wired to your pipes hung in the well, it should dissolve faster then the pipes.

Frank

The specification 'B&Q copper pipe' is not the most helpful description. But if you mean the thin-wall pipe used for small bore central heating (8mm and 10mm mainly) then the clue is in the words 'thin wall'. The pipe is made to hold hot water at low pressure, not steam at high. Thicker walled copper pipe is available - and should not contain lead, despite what Cup might allege. The motor trade uses copper brake pipe which is 3/16" diameter - perhaps a bit small for you, but able to stand 2000 psi. Old cars use 5/16" copper for fuel pipe, and generally thicker walled to make home forming less liable to go wrong. I have found that French DIY stores keep a wide range of copper pipe, in sizes that go up in millimeter units and 1mm wall thickness - dead handy is you need a sleeve joint.

Try Mallard metals or Noggin End for a UK supply.

Cheers, Tim

That would be zinc bar

in my club i need to provide receipts from reputable suppliers stating the copper is the correct grade for steam loco boiler use. there arent any 'short cuts' in this lark and you buy cheap crap at your peril. i also only buy my silver solder from reputable suppliers of the correct grade for boiler work with receipts etc. there are only 2 grades of silver solder now available for copper boiler work silverflo 24 and silverflo 55 and the cupalloys equivalent. buy copper or silver solder off ebay or anywhere else at your peril and expect your club boiler inspector to fail the boiler!

cheers,

julian

Julian, your boiler inspector must follow the green book guidelines - there is, to my memory, no such stipulation within it regarding the exact grade of solder to use, indeed im sure that low temp solder is still allowed if riveted properly. Neither is there any reference to the grade of copper to be used, except in the event of it being tig welded, which as an ex coded welder i fully support. Forgive me for saying this, but with the average age of our club member being 68 and the silly interpretations of current guidelines there simply will be no model steam makers within 20 years! Please define 'cheap crap'? i am very interested in this definition. And at what peril, I dont recall any model boilers ever exploding in the uk? Do you? I find this very same attitude in so many clubs, thoroughly without any real credibility and quite frankly it will be the death of what we all love. Indeed, way back as an apprentice I studied metallurgy, i obtained coded weld certs, i have built many successful boilers, i have in my workshop a stick, tig, mig and oxy set, and yet i am bound by the rules executed by an inspector who to date has produced just one 3.5 guage boiler - I know which boiler I would rater sit behind!

hi fizzy,

i dont disagree with your sentiments, but if our clubs specify A,B,and C and the unwary dont comply then that's the rules we have to follow these days if we we want to get a certificate and run for the public and get covered by insurance. i should add that ive seen quite a few horror stories boiler wise over the years plus laminated copper where the correct grade hasnt been used. i have built quite a few silver soldered copper boilers over the years, and would never dream of buying the materials and silver solder other than from a reputable ME supplier. the rules are quite straight forward and sensible and ought not to put off those making their own boilers so long as you are aware of the rules and comply with all the requirements.

ordinary plumbers grade copper is quite unsuitable for miniature loco boilers, and the few extra pounds buying the proper stuff from our well known suppliers is money well spent in my book, plus of course confidence that the correct grade has been used and that it will meet the club boiler inspector's approval.

cheers,

julian

Julian is that all plumbers copper? if so why.

Take a reputable pipe like Black lable, this is made from C106 which I believe is the type we should be using. Provided the thicknesses give teh required figures what is wrong with it.

Also why only those two solders from JM and Cup (not sure what maker they supply) why can't you use any make of AG155 solder, don't think the regs stipulat a supplier? I don't think there is anything to stop you using old stocks of easyflow either

Edited By JasonB on 07/03/2014 09:50:30

Perhaps the copper tube has changed sine the late 70s/ early 80s but we used standard central heating copper tube and fittings for special gas applications (mainly 15mm but larger bores too). We heated the Yorkshire fittings, shook the soft solder out, cleaned them and silver soldered them up to standard tube.

The assemblies/ pipe spools easily passed the most severe testing regimes before use. We used Easyflo No2 (probably not available now).

Julian, if your club is affiliated to Northern / Southern Federation it should only test boilers to the exact wording of those regulations. If the book says copper is to be a certain specification and receipts are needed, you need to provide them, I can assure you that there is no mention of grade of copper or silver solder in the Green book, it is just a case of your boiler tester being a prize "jobsworth". I feel that anyone imposing extra regulations should be reported to the Federation.

Fizzy, I agree with you absolutely.

hi jason,

johnson matthey recommend silverflo 55 and silverflo 24 for boiler work. there is no reason not to continue using easyflo or easyflo 2 if you have some left instead of silverflo 55.

i also agree that if you know the grade of copper you are using and its the correct grade as you state, then no problem.

my point was to warn the unwary of buying copper or silver solder off ebay or from the scrapyard or hardware merchants etc where the grade isnt known.

my club's boiler inspected asked me only this tuesday if i had the receipts for the copper on the current loco boiler i am building. i dont have a problem with that at all. i also have all the receipts for the boiler bush material etc

cheers,

julian

Im still struggling with most of this! Other than for tig work, when is the grade of copper the wrong grade(please dont confuse grade with thickness). And what do receipts prove other than how much you paid for an item? I fully agree with not buying SS unless you know the grade, but none of this goes any way to explaining why plumbers merchant tube isnt just as good as any other - and thats what I really want to understand, please. I also know that a club inspector is well within his right to add stipulations of his own, but it galls me when they do it simply to boost their ego. Ive made more boilers than half our club members put together but would it ever cross their minds to ask me to be an inspector, hell no, you have to be at least 70 years old first! Another small rant over.

Fizzy in one line you say don't buy SS unless you know the grade. Yet you then generalise by saying Plumbers copper and as I said above some may contain lead. However If you know the grade of the particular copper plumbing pipe then there is no problem as far as I can see.

Now if you go to B&Qs website I doubt they will give you much info on their copper pipe but go to a known maker such as Wednesbury who make the Black lable that I mentioned above and they will tell you its made with CW024A copper which is C106.

I would be carful if expanding any of the plumbing tube as it tends to have writing engraved down the side which could give problems getting it to seal. OK to solder though. But Teh thin wall is likely to make it unsuitable for a lot of applications in our world.

i think it is worth adding (and apologies for not referring to same earlier, but frank brown did) was that plumbing stuff is generally far too thin for boiler tubes. for a 5"g loco boiler we need 18swg or 20swg for superheater flues, and 20swg or 22swg for ordinary tubes depending on length and diameter and boiler pressure. some of the sizes are getting very difficult to obtain so you need to go up a swg size instead. i seem to recall that the theoretical thickness for 3/8" dia tubes is 8 thou but experience has shown that 20swg or 22swg is the minimum!

dont forget that a tube can be thinner if it has an internal pressure, but must be thicker if the pressure is outside the tube!

cheers.

julian

Got some specs here, hope it's readable. Ian S C

So what part of

7.4 The inspector shall satisfy himself:-

a. That the materials used are of the correct thickness and specification.

b. That, where required by the build procedure, the relevant
material certificates are provided.

Indicate that the Boiler inspector is overstepping the mark in asking for material certs?

How else do you check the material is to specification as I guess not many clubs have got a spectrometer PMD (Positive material identification)

I think that many forget that boiler inspectors are personally liable if there club hasn't take out the specific insurance to cover the boiler inspectors.

Steve

I think life is much easier if you treat your Club/Society's Boiler Inspector a bit like your Wife.

Ask them what they want (or would prefer) and then just do it. It's much less painful in the long run

Regards,

IanT.

S.D.L. Receipts are pointless, all they prove is that on a particular day you purchased something. Julian Atkins boiler inspector should ask for Certificates of Conformity if he is concerned about the type etc of the material. By wanting a receipt all he is proving is that it was paid for and not nicked