Author Topic: Copper for boilers  (Read 16361 times)

Offline Barneydog

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Copper for boilers
« on: January 04, 2017, 10:20:47 AM »
Hi Guys,

I am just ordering copper for my new boiler.
Which should I use and why?
The choice is expensive C106 grade or cheaper C101 grade?
I am told that C106 grade is only used by the professional boiler making companies But that the difference is minimal.

Thanks

Julian

Offline Jo

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Re: Copper for boilers
« Reply #1 on: January 04, 2017, 01:17:27 PM »
Quote from SandyC  8)

Quote


For copper boilers which are silver soldered/brazed the copper grade most specified and acceptable to the boiler inspectors is: -

C106 Copper

Phosphorus deoxidised copper is the grade of copper where oxygen is removed by the controlled addition of phosphorus during the melting cycle. A slight excess of phosphorus ensures complete removal of oxide. The residual phosphorus remains alloyed with the copper within the specified range 0.013-0.050%. The copper content is 99.85% minimum and the grade conforms to the compositional requirements of British Standard alloy designation C106.
C106 is superior to the electrolytic tough pitch copper electrical grade (C101) and should be specified for all non-electrical applications, especially those involving assembly by welding or brazing. Phosphorus deoxidised copper is not susceptible to hydrogen embrittlement which is a serious risk with non-deoxidised grades.

Related Specifications

BS2871.
Cu-DHP.
DIN 1787.

You want the C106.

But most model engineering suppliers only supply C101  :wallbang:

Jo
Enjoyment is more important than achievement.

Offline Bluechip

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Re: Copper for boilers
« Reply #2 on: January 04, 2017, 01:33:52 PM »
M-Machine do C106 .  :ThumbsUp:

And a belated Happy New Year to All ...  :cheers:

Dave


Offline AOG

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Re: Copper for boilers
« Reply #3 on: January 04, 2017, 01:59:03 PM »
What about C122?  C106 is almost unobtanium around here.

Thanks

Tony

Offline SandCam

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Re: Copper for boilers
« Reply #4 on: January 04, 2017, 04:20:29 PM »
What about C122?  C106 is almost unobtanium around here.

Thanks

Tony

Hi Guy's and Gal's and A Happy New Year to you all.

Tony,

C122 has almost identical characteristics and is also Phosphorous deoxidised... it is therefore is a perfectly suitable alternative to C106.

Whatever you do... don't use, or accept, C101 or C103... they are not oxygen free, despite what some suppliers say, they are both actually a Low Oxygen grade... the exact quantity not being specifically controlled during manufacture.

You may need to obtain 'certificates of conformance/authenticity' for all the materials you use in your boiler construction nowadays, depending on your country of origin, this is certainly the case for the UK, especially for boilers over 2litres capacity which fall into groups I -IV of the PER (Pressure Equipment Regulations) regulations.

Note... Commercially built boilers which fall into the above groups MUST be CE marked... However, I have, so far, been unable to establish whether this now also applies to Home built boilers after they have obtained test certification... most sources are a bit vague on this requirement.
The Green Book suggests that they should not.

Small boilers of under 2litres capacity, regardless of working pressure, fall under the S.E.P (Sound Engineering Practice) group of the PER and should not be CE marked, commercial or otherwise.

Check with your boiler inspector before doing or purchasing anything. The latest UK test code (Green Book) now requires a Written Scheme of Examination for each and every boiler being tested, regardless of size/capacity, and this will list the certificate serial numbers and materials used.
Failure to provide this information could prevent you getting your boiler tested. :facepalm:

Other countries will have their own rules, so these check first.

I hope this helps.

Best regards.

Sandy. :D



 
« Last Edit: January 04, 2017, 05:04:21 PM by SandCam »

Offline Jasonb

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Re: Copper for boilers
« Reply #5 on: January 04, 2017, 04:23:39 PM »
Macc Models is another source of C106, Noggin End and GLR Kennions do C106 tube too
« Last Edit: January 04, 2017, 04:29:38 PM by Jasonb »

Offline Barneydog

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Re: Copper for boilers
« Reply #6 on: January 04, 2017, 09:28:40 PM »
All the tube is not an issue as it is all C106. It is just the plate which was C101. He has now found some C106 plate big enough for me. He will issue a receipt stating it is C106 which should be ok with the inspector. Sandy C sent me a very direct email today stating that C101 must never be used. Many thanks Sandy for the guidance.

This now gives another question. I have several good lengths of copper tube in my workshop from various sources designated for several future projects.....Don't we all!!!??? Without certification/receipts how can we tell the grade of the copper?


Happy new year

Julian

Offline tangler

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Re: Copper for boilers
« Reply #7 on: January 05, 2017, 02:33:58 AM »
I think the worms are wriggling out of the can here.  It seems to me that, in the UK, for a home constructed copper boiler made using silver soldered joints, a boiler inspector will not expect to see material certification.  This therefore implies that any nominally pure copper is adequate for the purpose, as has been demonstrated by every amateur boiler maker since records began.  The requirements for welded copper boilers are entirely different since the construction method involves melting the copper with a consequent drastic change to the metallurgy.  I suspect there is confusion between the 2 requirements.  I may be entirely wrong but until some body can show me chapter and verse I shall continue to offer boilers constructed from copper bought, without tracability, from  the ME trade, to my club inspector.

Cheers,

Rod

Offline michaelr

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Re: Copper for boilers
« Reply #8 on: January 05, 2017, 09:31:55 AM »
Rod. Your view on building copper boilers and the material used is the most common sense and practical approach to the subject that I have read for some time, and also in my opinion and I agree is all that is needed.

Mike

Offline SandCam

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Re: Copper for boilers
« Reply #9 on: January 05, 2017, 02:48:24 PM »
I think the worms are wriggling out of the can here.  It seems to me that, in the UK, for a home constructed copper boiler made using silver soldered joints, a boiler inspector will not expect to see material certification.  This therefore implies that any nominally pure copper is adequate for the purpose, as has been demonstrated by every amateur boiler maker since records began.  The requirements for welded copper boilers are entirely different since the construction method involves melting the copper with a consequent drastic change to the metallurgy.  I suspect there is confusion between the 2 requirements.  I may be entirely wrong but until some body can show me chapter and verse I shall continue to offer boilers constructed from copper bought, without tracability, from  the ME trade, to my club inspector.

Cheers,

Rod

Hi Rod,

See paragraph 7a and 7b of the Green Book...AKA

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

quote...

"The inspector shall satisfy himself:-

7a.  That the materials used are of the correct thickness and
specification. 

7b.  That, where required by the build procedure, the relevant
material certificates are provided."

A lot of this has come about by changes to the PER regulations since 2002 and the inspector would be perfectly within his rights to ask for such certification in order to approve a home built design.

Even if the boiler was being built to a published design, he would still be within his rights to ask for these in order to verify that the materials used are as specified on the design drawings. 

He MAY also request viewing of same even for a commercial boiler.

Using unknown, or incorrect, grades of Copper for boiler work can lead to early joint failure, or worse, often due to using Copper containing Oxygen which can quickly lead to cracking caused by Hydrogen embrittlement.
Not a safe situation for a steam pressure vessel.

Best regards.

Sandy. :)
Retired manufacturer of Model steam boilers and engines.


Offline Jasonb

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Re: Copper for boilers
« Reply #10 on: January 05, 2017, 04:10:56 PM »
Even if the boiler was being built to a published design, he would still be within his rights to ask for these in order to verify that the materials used are as specified on the design drawings. 
Sandy. :)

Problem is how often do you see the grade of copper specified on an ME drawing?

Offline Tennessee Whiskey

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Re: Copper for boilers
« Reply #11 on: January 05, 2017, 09:22:34 PM »
If you have to have a boiler inspected you can expect to satisfy the inspector; plain and simple. The specs and regs are written to cover the safety and well being of all, and to be honest, the insurance companies. As with any law, rule, regulation, or specification ever written, there is room for "interpretation" , however, common sense will virtually never enter into that interpritation. You can spend hours and dollars arguing an "interpretation" , or, if you want the "stamp" painlessly, give them exactly what they ask for, or even upgrade( however that could bring on more explanation and then more interpretation  :facepalm:). In regards to Jason's last post: if you are taking as much time as it takes to construct a nice boiler, take the time to confer with the inspector. Show him the drawings, discuss materials( I.e. grade not specified) , and genuinely inquire of what he expects. Now, so y'all don't think old Cletus has lost it; I'll sign this post the way I would have when I had a real job.

H. Eric Douglas
Boiler Inspector/ Welding Engineer
BE&K Construction
Birmingham, Al

Offline Firebird

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Re: Copper for boilers
« Reply #12 on: January 05, 2017, 10:15:31 PM »
Hi

To pick up on my mate Julians question, is there a way of telling the difference between C101 and C106. Over the years I have picked up various bits of copper tube from steam fairs and model engineering shows which I hope will become boilers to power mostly stationary engines. I understand that copper tube is always C106??? I have a very nice piece of 4" tube 12swg that is obviously old. It was actually donated by our old friend John Bogstandard but I have no paperwork to say what it is. I have a few pieces of copper plate that I have picked up here and there but none of it is marked. Is C106 marked??? How can we be sure that even if the vendor says it is C106 that is actually what we get???

Cheers

Rich

Offline 10KPete

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Re: Copper for boilers
« Reply #13 on: January 05, 2017, 10:55:03 PM »
I'll re-ask part of Rods post: reworded: Is silver brazing going to result in an oxygen problem the same as welding would??? Brazing doesn't melt the base metal....

Pete
Craftsman, Tinkerer, Curious Person.
Retired, finally!
SB 10K lathe, Benchmaster mill. And stuff.

Offline tangler

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Re: Copper for boilers
« Reply #14 on: January 05, 2017, 11:07:17 PM »
Folks,

I think the "Green Book" that Sandy refers to is this: http://www.nameng.org.uk/images/Boiler_Testing_Documents/2012_Test_Code_V12a.pdf

This document is the one that the insurers of our clubs use to guide the "amateur" club members who have taken on the responsibility of certifying boilers as safe to use.  It really is pretty vague and my interpretation of that is that here in the UK we have a successful self regulation system for model locomotive boilers outside of the regulations that apply to commercial and professional use and everybody is happy to keep it that way.

"1.2    Legal   requirements,   such   as   the   Pressure   Systems   Safety
Regulations  2000  (PSSR),  do  not  normally  apply  to  persons
operating  pressure  equipment  as  a  hobby  activity.  However  the
Health and Safety Executive considers it good practice for persons
using  such  equipment  to  provide  the  same  level  of  health  and
safety protection as they would if they were duty holders under the
Regulations. To aid this process the principles (my italics) of PSSR have been
followed in drafting this document..."

The Written Scheme of Examination is not prescriptive, all it says is that the procedure that is used to examine the boiler is written down and lodged as part of the certification.

The only mention of material certification is :

"7. b.That, where required by the build procedure  (my italics), the relevant material certificates are provided."

I interpret this to refer to welded boilers, not those that are silver soldered.

My boiler inspector has visually examined the quality of my silver soldering so far and is happy that it looks right.  He will want to examine the quality of the silver soldering on the crown stays before the boiler is closed and will then have a look at the complete thing before doing an hydraulic test.  He seems to be happy that the boiler is made of copper (unspecified), has bronze (not brass) bushes, is constructed with a variety of silver solders and is to an established design.

The interpretation of the Boiler Testing document is perhaps coloured by whether one is looking at it from the commercial viewpoint of a professional boiler maker where traceability is required or from the the amateur maker following successful procedures that have been used by followers of the hobby for over 50 years.  Perhaps this why Sandy and I differ in our views.

Best wishes to all,

Rod


Rod






 

 

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