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Weldsol

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OK - - - - I thought maybe, using stringer beads as outlined in your pdf, that might be what one would do.
Still a cow to do - - - me, your amperages - - - that would be for 3.2 mm electrodes - - - for 4.0 I would likely be in the 190 A range.
Need to have things 'hot' to keep that slag burned out. Even with cleaning between passes (likely wire brush of some kind) if you want clean welds with very very low to no porosity - - - you will be running HOT. (Keep a tight weld arc and the high heat isn't an issue!)
I hope that this was horizontal or flat welding - - - - vertical up would have been a serious gong show (IMO). (And for overhead - - - - find another turkey would have been my response!!!)

Isn't it amazing what the guys on the tools have to fix for the suits that can't get things right - - - lol
No they were 4.0mm you could not have done it at 190A with the access and the rod angle you wouldn't control the weld pool that is the top whack for a 4.0mm low hydrogen They tend to run across the range of 120-190 depending on what you are trying to do (Amperage ranges can vary slightly with different manufacturers on the same electrode type)
The weld position was carried out as per drawing on PDF
paul
 

Weldsol

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No they were 4.0mm you could not have done it at 190A with the access and the rod angle you wouldn't control the weld pool that is the top whack for a 4.0mm low hydrogen They tend to run across the range of 120-190 depending on what you are trying to do (Amperage ranges can vary slightly with different manufacturers on the same electrode type)
The weld position was carried out as per drawing on PDF
paul
Just to go back to the early posts about using published designs for boilers I found some pictures of my finished Shay boiler (sorry about the quality of the pic's as I couldn't find the pic's on this computer they are in some storage device around the house, so had to go to the other forum that I'm on to find them and take a picture with my phone)( note it shows my Bridgeport mill which I got rid of and down sized to a smalller one 2yrs ago)

This boiler uses the published design by Kozo Hiraoka but could not be used in the UK (unless you changed something) can you spot it.
Paul
Kozo Hiroka Boiler design.jpg
LH side view.jpg
RH side view.jpg
Shay boiler backhead.jpg
 
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Hi Paul, I have been learning a lot from your posts, THANKYOU!
But I cannot spot what would need to be changed for the UK? - Perhaps you can tell? (Start a conversation if you want to keep others guessing a while longer!).
A couple of ideas though.
1: The M10 stay bolts: I think in the UK they must be fully welded, noy threaded and sealed. This to avoid the thread - or plain shaft on t'other end) from corroding as it is unsealed on the wet side? - Thus a trap for corrosion and consequential weakening?
2: Likewise the bushes: full penetration welds requires so no internal trap for corrosion.
3: the flue tubes: I understand they should be swaged (rolled) into the end plates, not welded?
4: No longitudinal seams permitted on the shell tubes... - unless made (Commercially?) "in a factory" by submerged arc or other controlled machine process and proven by expensive examination and certification... Seamless "oil industry" pipe is the UK standard I think?
But I am probably completely off target... just a new pupil to this stuff!
K2
 
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Hi again:
5: Maybe the UK prohibition is the slot weld for the brace at the top of the firebox: where welded to the outer shell?
6: Perhaps some wall thickness constraints: The UK corrosion addition to "stressed steel thickness" is >1/8inch on every wet surface. - Recommended MIN 1/4" thick for everything: I think your shell is only 5mm thick?
Running out of ideas now: just learning!
K2
 
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Weldsol

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Hi again:
5: Maybe the UK prohibition is the slot weld for the brace at the top of the firebox: where welded to the outer shell?
6: Perhaps some wall thickness constraints: The UK corrosion addition to "stressed steel thickness" is >1/8inch on every wet surface. - Recommended MIN 1/4" thick for everything: I think your shell is only 5mm thick?
Running out of ideas now: just learning!
K2
I thought you would get to the main reason, yes only 5mm wall and not 1/4" (please note my boiler was made using shed 40 so had a wall of 7.11mm)
I didn't use the slot weld (used a full pen, T butt )
All welds where they was a through the shell bush were tophat so the bushes were stepped and installed from the inside, TIG welded on the inside and outside (apart from the steam dome boss which was fully beveled on the shell and then welded inside and outside with the correct E7018 electrode)
The side stays were welded into the firebox prior to assembly and for the final outer joints were stepped (note machined before being welded to the firebox) to give a 2mm landing and the holes in the shell drilled 4mm bigger and bevelled, this enabled to achieve full penetration (TIG root and E7018 filled)
All of the shell welds (with the exception of the back head and the front tubeplate which were fully bevelled and welded as a single sided T butt) were TIG rooted from the inside then cleaned up on the outside to then fill with the E7018
Because I had changed to a thicker shell I did not have to submit calc's to the boiler inspector, and I had shown him the weld prep's he was satisfied. My boiler was completed and hydraulic tested to 200 psi (in 2010) and hydraulic tested ( with all the fittings on except safety valves ) then steam tested in 2019
Paul
 

ajoeiam

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blank (like some others I've noticed)
I thought you would get to the main reason, yes only 5mm wall and not 1/4" (please note my boiler was made using shed 40 so had a wall of 7.11mm)
I didn't use the slot weld (used a full pen, T butt )
All welds where they was a through the shell bush were tophat so the bushes were stepped and installed from the inside, TIG welded on the inside and outside (apart from the steam dome boss which was fully beveled on the shell and then welded inside and outside with the correct E7018 electrode)
The side stays were welded into the firebox prior to assembly and for the final outer joints were stepped (note machined before being welded to the firebox) to give a 2mm landing and the holes in the shell drilled 4mm bigger and bevelled, this enabled to achieve full penetration (TIG root and E7018 filled)
All of the shell welds (with the exception of the back head and the front tubeplate which were fully bevelled and welded as a single sided T butt) were TIG rooted from the inside then cleaned up on the outside to then fill with the E7018
Because I had changed to a thicker shell I did not have to submit calc's to the boiler inspector, and I had shown him the weld prep's he was satisfied. My boiler was completed and hydraulic tested to 200 psi (in 2010) and hydraulic tested ( with all the fittings on except safety valves ) then steam tested in 2019
Paul
Hmmmmmmmm - - - - did you do your own welding?
Dunno how it shows to others but here - - - the pics are a bit fuzzy.
 

Weldsol

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Hmmmmmmmm - - - - did you do your own welding?
Dunno how it shows to others but here - - - the pics are a bit fuzzy.
Yes I did do all my own welding I did explain in the previous to please excuse the photo's as I had to go onto the uk site that I use to pull out the pic's (from 2010)
I will send you a PM
Paul
 
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Thanks Paul. I think if I were the inspector, I should approve that one, based on your helpful explanation of the welds! I have a magazine article by Kozo-San on copper boilers - using the Shay as an example, and it explains the ASME rules in words I understand - including the test pressures based on Max pressure in service. Because the copper loses strength significantly at steam temperatures there is a factor to take the initial hydraulic test to an elevated pressure at room temperature to simulate the working temperature stress condition. I guess this is different for steel boilers to ASME? So, what is the certified steam pressure (max.) for your boiler - from the 200psi hydraulic test? - I understand initial hydraulic testing to be at twice NWP for UK, Steam test at Safety lift of less than 1.1 x NWP. But ASME does it all based on "max steam pressure" = Safety certification pressure: with the safety valves fully lifting at <(NWP + 6%). Please correct me where I am wrong.
Thanks,
K2
 
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Weldsol

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Thanks Paul. I think if I were the inspector, I should approve that one, based on your helpful explanation of the welds! I have a magazine article by Kozo-San on copper boilers - using the Shay as an example, and it explains the ASME rules in words I understand - including the test pressures based on Max pressure in service. Because the copper loses strength significantly at steam temperatures there is a factor to take the initial hydraulic test to an elevated pressure at room temperature to simulate the working temperature stress condition. I guess this is different for steel boilers to ASME? So, what is the certified steam pressure (max.) for your boiler - from the 200psi hydraulic test? - I understand initial hydraulic testing to be at twice NWP for UK, Steam test at Safety lift of less than 1.1 x NWP. But ASME does it all based on "max steam pressure" = Safety certification pressure: with the safety valves fully lifting at <(NWP + 6%). Please correct me where I am wrong.
Thanks,
K2
My boiler was tested to the requirements of the Southern federation Boiler inspectors for 7 1/4" gauge so it came under the UK 2x WP
For ASME min, test psi =1.3 x MAWP at test temp, x lowest stress at test temp, to stress at design temp it doesn't state a maximum test psi
 
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