Which material spec’s for boilers ?

[Roderick JenkinsParticipant @roderickjenkins93242]

I'm not trying to circumvent the "rules", just trying to clarify what they actually are.

Rod

[V8EngParticipant @v8eng]

Rod my post was not aimed at you, just at the general direction some of this seemed to be going.

Edited By V8Eng on 01/08/2016 19:54:04

[Neil WyattModerator @neilwyatt]

Posted by Roderick Jenkins on 01/08/2016 16:29:34:

This appears to be the boiler testing code for the UK **LINK**

A commercially made boiler isn't defined but the code seems to assume that it is presented to the boiler inspector as a completed item. If Ken's friend were to turn up with a partially completed boiler so that the joints could be inspected and then return with the completed boiler ready for testing would that be a commercial boiler? Who would know who built it? Is it the mere fact that money has changed hands that is important or is it that a commercial boiler is assumed to have already undergone some testing, as demonstrated by the CE mark?

Rod

The assumption is that a commercial boiler will be fully documented to demonstrate it meets the standards. The CE mark means the tester doesn't have to check those things – they can take them as read and their job is to undertake the pressure tests and check for damage, leaks, suitable fittings etc.

If the boiler then goes 'pop' because it was made of the wrong material or construction, for example, the boiler tester can say 'it was CE marked so I had to assume the materials and construction met the required standards' and the insurers will go after the maker instead.

Neil

Neil

[duncan webster 1Participant @duncanwebster1]

Posted by Neil Wyatt on 01/08/2016 09:26:40:

Posted by ken king, King Design on 01/08/2016 00:28:34:

I'll study the Australian code, but why has it apparently been dismissed in some quarters ?

The Australian code produces a boiler capable of containing a tactical nuclear weapon, but it is about construction not the audit trail you will need to follow to build a CE marked boiler.

UK Pressure Vessel Regulations

I've posted on another thread about people talking rubbish about the Australian code, Neil is at it now. Has he ever read it? If so he will find that it compares well with design rules suggested by Don Young, Martin Evans et al, and with the requirements of BS5500, which is probably out of date now and was for unfired pressure vessels, but I've got a copy from previous work.

[ken king, King DesignParticipant @kenkingkingdesign]

My head is beginning to spin with all this, and I'd like to make sure I've understood what is being said, so let me paraphrase it, then correct me if I'm wrong please.

A fullblown manufacturer must have his model boilers made from certified materials, using certified manufacturing methods and to certified performance standards, then his products can carry the CE mark. This indicates the conformity with standards and regulations for the product type of all EU member countries, and is understood and required throughout the EU. Presumably the manufacturer will have passed stringent audits and then been given approval to CE stamp his products. I'm not sure what part the club inspector then plays when such a purchased product is incorporated into a model. Does he simply examine changes or additions made by the modeller?

If a modeller builds his own boiler he doesn't need to use certified materials, can make it up as he goes along, and provided everything he uses and does appears sensible and well-done, as agreed by a club inspector, then he will be able to insure the boiler and use it within the public domain.

If the preceding paragraph is correct then I take Rod's point that it shouldn't make any difference if the modeller has asked a friend to make it for him; the identity of the maker is not an inspection issue. It surely follows that it is also irrelevant if the modeller has paid his friend to undertake the work; it doesn't materially affect the boiler in any way. I'm not arguing any case here, just trying to get it straight in my head, so disagree if you wish.

What I find a little strange is that with a home-built boiler the club inspector won't be certain of the origin or detailed specification of the materials used, as there may be no traceability, and yet if he approves the boiler it too can be insured and used within the public domain, alongside the CE marked product.

Your comments please ?

[julian atkinsParticipant @julianatkins58923]

Hi Ken,

Depending on the club, most club boiler inspectors these days adhere to a very strict regime of insisting inspection of construction as it progresses and examining all internal joints, and seeing paperwork for boiler materials etc.

In short, 'home made' boilers by the amateur are expected to meet the same criteria of commercially made boilers.

My last 2 boilers have certainly undergone quite a thorough inspection at all stages by the club boiler inspector. This is very good practice. I have witnessed at least 2 amateur boilers fail due to the crown collapsing, and quite a few other horrors over the last 33 years in this lark.

Cheers,

Julian

[Paul LousickParticipant @paullousick59116]

Hi Ken,

You comment "If a modeller builds his own boiler he doesn't need to use certified materials, can make it up as he goes along, and provided everything he uses and does appears sensible and well-done, as agreed by a club inspector, then he will be able to insure the boiler and use it within the public domain." is correct. What you make in your own backyard is up to you.

BUT, and a big but, is if the boiler is sold to someone as an approved boiler or is used in the public domain and someone is hurt you may be liable for compensation. If the club inspector passes an unsafe boiler he may be the one which is taken to court. This is why he needs to be sure that it is built correctly from approved materials.

The Australian code is not just for testing the boiler but is also a complete design guide which specifies the type and thickness of materials, weld preparations, types of fittings, etc. as shown below.

Paul.

[Simon CollierParticipant @simoncollier74340]

That looks like the steel boiler code. There are also the copper code, the Duplex code and the sub-miniature boiler code. If anyone is interested in the history of the Australian code: http://www.aals.asn.au/AMBSC/AMBSC.htm

[Paul LousickParticipant @paullousick59116]

Simon,

Yes, it is the code for steel boilers. I do not have the one for copper but imagine that it would contain similar details.

Paul.

[David JuppParticipant @davidjupp51506]

Posted by ken king, King Design on 01/08/2016 23:25:42:

A fullblown manufacturer must have his model boilers made from certified materials, using certified manufacturing methods and to certified performance standards, then his products can carry the CE mark. This indicates the conformity with standards and regulations for the product type of all EU member countries, and is understood and required throughout the EU. Presumably the manufacturer will have passed stringent audits and then been given approval to CE stamp his products.

Depending upon the Category of the boiler under PED, the level of requirements differ. At higher categories the manufacturer can choose between a 'Quality Systems' approach where the Notified Body audits company systems, or a more direct involvement where Notified Body inspects the item being made. At lowest levels, no audits are required, nor any other Notified Body involvement.

In all cases I'd expect certified materials to be used.

PED separates 'Design' and 'Manufacture' into distinct activities, each of which may or may not require NB involvement.

[Neil WyattModerator @neilwyatt]

My (exaggerated) reference to the generous corrosion allowances of the the Australian code reflects that their approach is belt and braces and more prescriptive than the UK one. A boiler built to the Australian code may not meet UK requirements and vice-versa – in particular Briggs boilers are the norm down under and rare over here so many UK inspectors may be unfamiliar with them and how to test them.

Neil

[Michael GilliganParticipant @michaelgilligan61133]

Ken,

Further to my comments, yesterday:

Here is my 'opinion' [as a Commercial/Contractual Specialist, not a Boiler-Maker], which may, or may not, help focus your thinking:

• Your friend wants a 'Boiler', and [if he chooses to use it as such] will need all the certificates & insurance appropriate to the circumstances.
• You, however [whether as Ken King the person, or as 'King Design' the company] could agree to supply a copper vessel.
• The vessel does not become a 'Boiler' unless and until it is certificated as such.

MichaelG.

[Roderick JenkinsParticipant @roderickjenkins93242]

Posted by ken king, King Design on 01/08/2016 23:25:42:

If a modeller builds his own boiler he doesn't need to use certified materials, can make it up as he goes along…

My understanding is that for the boiler to be insurable; it has to be to a recognised and established design or calculations have to be provided to show that the material thickness, staying etc are adequate to give the required safety factor. There does not appear to be a requirement to show traceabilty of the material specs but for silver soldered copper boilers I believe any commercially available copper will be appropriate. The boiler kit I have just bought from Blackgates contains no material certification. The situation for inspection and material certs. for welded boilers will be very different.

I'm coming to the conclusion that for a "commercial" boiler with a CE mark the inspector will assume that all the joints he can't see are good. For a "non-"commercial" boiler then the inspector will wish to see the quality of the joints that may be hidden on completion during construction and before they are sealed away.

Rod

[S.D.L.Participant @s-d-l]

Posted by Roderick Jenkins on 02/08/2016 10:03:41:

Posted by ken king, King Design on 01/08/2016 23:25:42:

If a modeller builds his own boiler he doesn't need to use certified materials, can make it up as he goes along…

My understanding is that for the boiler to be insurable; it has to be to a recognized and established design or calculations have to be provided to show that the material thickness, staying etc are adequate to give the required safety factor. There does not appear to be a requirement to show traceabilty of the material specs but for silver soldered copper boilers I believe any commercially available copper will be appropriate. The boiler kit I have just bought from Blackgates contains no material certification. The situation for inspection and material certs. for welded boilers will be very different.

I'm coming to the conclusion that for a "commercial" boiler with a CE mark the inspector will assume that all the joints he can't see are good. For a "non-"commercial" boiler then the inspector will wish to see the quality of the joints that may be hidden on completion during construction and before they are sealed away.

Rod

Your first paragraph is fundamentally correct, but check if the drawings have blind bushes for the firebox door etc and if not discuss changing from tapped firebox to blind bushes with your club boiler inspector.

The best guide for checking design thickness / stay centers in the UK in my opinion is the Northern Association guide that you can buy for about a pound at some exhibitions, This may be adopted by the southern fed at some stage and was recommended at the joint boiler testers conference I went to.

We will test certified professional steel boilers but we will not certify a build at our club ( Banbury Model Engineers)

Steve

[nigel jones 5Participant @nigeljones5]

I have always had to show material certs for the steel main tube I use and in doing so are safe in the knowledge that the steel I am using is of decent grade – although I cant make any sense of the mill certs as they are written in Chinese! (Most boiler inspectors don't do Chinese either but all are very happy to just have a copy of the cert). If you paid someone to weld the boiler you would have to produce the weld cert at the time of testing. This seems perfectly sound to me, indeed it shows that the welds should be top quality and thus need no additional checking but im pretty sure that the Green book regards this as now a commercial build. I need to recheck this! I have been asked to make boilers for other people which I will gladly do, but only for fellow club members and not for profit. At the end of the day you need to establish with your club inspector what he will and will not allow. Whilst the regulations are tight in some places they are terribly woolly in others and are open to massive interpretation (and dare I say abuse). I generally build boilers to my own design i.e. not published. I have absolutely no problem getting them past the boiler inspector as he is a practical helpful chap but I have also encountered inspectors who take it upon themselves to block a build at every opportunity simply because they can.

[ken king, King DesignParticipant @kenkingkingdesign]

First of all a big thank you to all who generously contributed their time and knowledge to this thread. When I first posted my enquiry about materials I didn't expect such a flurry of responses, nor the wealth of information on boiler inspections and certification, an area of which I was woefully ignorant.

I've concluded that it would be extremely difficult, if not impossible, for me to successfully navigate such potentially stormy waters, and have therefore notified my friend/client that I cannot undertake to make his boiler. I expect several of you are sighing with relief, with some justification as I now understand.

Thanks again, and happy steam-raising to you all,

Ken.

[Ian S CParticipant @iansc]

A bit of copper trivia from the junk pile, of interest ; maybe /maybe not.

Ian S C

[Frank BrunnerParticipant @frankbrunner42168]

Hi There,

Any ideas, suggestions on using phosphor bronze instead of copper on a vertical kingdon boiler?

The idea was to use a turned phosphor bronze ring for the bottom section to join the firebox to the outer shell.

A second phosphor bronze ring would be the transition piece between the top and bottom part of the boiler to join the two different diameter copper pipes.

Any input on this topic would be much appreciated…

Cheers

Frank

[Brian HParticipant @brianh50089]

The document;

The EXAMINATION & TESTING of MINIATURE STEAM BOILERS (Revised Edition 2012)

is out of date and has been superceded by;

The Boiler Test Code 2018
VOLUME 2 – Boilers under 3 bar litres
Effective from 1st May 2018

for copper boilers for UK use.

Brian

[Harry WilkesParticipant @harrywilkes58467]

Posted by Neil Wyatt on 01/08/2016 21:13:15:

Posted by Roderick Jenkins on 01/08/2016 16:29:34:

Neil

the link refers to a out of date issue the new version was issued in 2018 and in now divided into 3 section which can normally be found here

This appears to be the boiler testing code for the UK **LINK**

A commercially made boiler isn't defined but the code seems to assume that it is presented to the boiler inspector as a completed item. If Ken's friend were to turn up with a partially completed boiler so that the joints could be inspected and then return with the completed boiler ready for testing would that be a commercial boiler? Who would know who built it? Is it the mere fact that money has changed hands that is important or is it that a commercial boiler is assumed to have already undergone some testing, as demonstrated by the CE mark?

Rod

[Nigel Graham 2Participant @nigelgraham2]

One area of confusion this thread shows is that of different countries with different ideas and requirements. The UK for example is still terrified of stainless-steel boilers yet other countries use them – though perhaps trade-only thanks to the considerable technical difficulties. Similarly with silicon-bronze: again perhaps trade-only to ensure the correct of many grades of a seemingly simple trace-alloy. On the other hand, the Australian code is regarded with suspicion in the UK as being excessive; outlawing even popular, tried-and-trusted conventional locomotive boilers on mere principle – but I admit not knowing how true or rumoured this is.

'

The UK model-engineering bodies follow the EU's Pressure Equipment Regulations, which unless radically revised from my own, early, copy, have very little technical information, and thinks PVs are only made from stainless-steel or aluminium-alloy. Note the irony?

The PER were obviously by lawyers not engineers, and primarily part of the political and economic scheme badged "CE" mark, and to keep "Notified Bodies" in clover. However, they are clear that safety is paramount in design and construction, and contain the clause, the pressure-vessel "does in fact have to be safe". I think its "in fact" is literal, not merely colloquial – though in entirety the clause seems an afterthought.

("Notified Body" is EU-Speak for a Laboratory, approved Governmentally for testing products.)

Where that leaves us in the UK is having to work to our own, MELG-agreed Test Code, "The [Colour] Book", presently orange. It takes in the PER's random technical specifications intended for the petro-chemicals and nuclear trades, and if anything gilds them. Unravel the book's tangled layout, work to its guidance and you won't go far wrong, whether you buy a commercially-made, CE-marked boiler or make your own.

For amateur construction, really we are limited to copper only, Steel boilers are now so problematically wrapped in materials' and welders' specifications that they are trade-only – so must pass all those costly PER hoops.

Copper: there is really only one grade of copper, the essentially-pure metal, easy to buy through the model-engineering trade; and for amateur construction at least not needing materials certificates. The processed form called "Phosphorus De-oxidised" is for welding, but really again, trade-only practice.

Use a recognised, published design if possible, or at least use those design principles, use the appropriate bronze for bushes (not brass); seek your club's boiler-inspector's advice.

Now I recognise two problems with the last point.

1) I am lucky – my two societies' boiler-inspectors understand their roles, and what the Orange Book actually says. Such volunteers – who do not need a professional engineering background – have an escape in the code, allowing them to decline testing a boiler if they have good reasons that can include it being too far outside their experience. Unfortunately there seems many anecdotes about some boiler-inspectors being far too finicky, refusing the test or failing a boiler, through fear of the responsibility and not understanding the spirit and requirements of the MELG Code. Though I have some sympathy with the latter, as the book is confusing.

2) You might not actually be in a model-engineering society! That almost certainly means if you wish to steam the plant in public, to be covered by insurance you will have to buy a commercial steam-test. Not difficult to arrange, but expensive. My advice, frankly, is to join a MELG-affiliated club if at all possible… but on a social note, please don't join merely for the boiler test. The society will test it, and for "free" (it is not allowed to charge for testing boilers), but as with any social organisation respect is a transaction, and you are expected to give as well as receive, take part in its activities generally, and so on.

'

So to answer the question, by all means study the reputable, up-to-date model-engineering literature on boiler-making, make the boiler… but don't so "by way of trade". In other words while I think it reasonable your friend buys the materials, do not charge for your time as that would make a somewhat grey area even greyer.

'

Selling an amateur-built boiler, with current test-certificate, as Roderick says, is not a problem if it's a private sale. The law is concerned that new boilers "Placed on the market" and "by way of trade" (i.e. commercially) after a certain year – I forget when it was – comply with the PER. It does not apply to older boilers though obviously these still need testing.

Nor as far as I understand it, would it apply to an ad-hoc sale of a boiler as part of a project unfinished by illness or death – it's still a private sale of someone's private possessions. Though the buyer would still reasonably want test-certificates (the MELG scheme allows for these being long-expired or lost, by treating the boiler as if "new".)

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