UW-12(f)
UW-12(f)
(OP)
Hi
How do you treat requirements of UW-12(f)? My access to ASME interpretations just expired, maybe someone could help me:
1. Does it require to make these tests only once in a lifetime or each time a new vessel is welded?
2. Does it require to make a test on fillet or edge welds? What about tube-to-tubesheet?
3. Does it require to make a test on each thickness/material combination when a production joint is between different materials?
4. Does it allow making only side bends testing regardless of material thiskness? What about, say 0.6mm?
Thanks,
Konrad
How do you treat requirements of UW-12(f)? My access to ASME interpretations just expired, maybe someone could help me:
1. Does it require to make these tests only once in a lifetime or each time a new vessel is welded?
2. Does it require to make a test on fillet or edge welds? What about tube-to-tubesheet?
3. Does it require to make a test on each thickness/material combination when a production joint is between different materials?
4. Does it allow making only side bends testing regardless of material thiskness? What about, say 0.6mm?
Thanks,
Konrad





RE: UW-12(f)
For question 1, I would guess the intention was to test once for all vessels unless the tests are no longer representative of the production welding on each vessel.
I cannot answer 2,3 or 4
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RE: UW-12(f)
I'm kind of guessing at the following answers to your questions, since your configuration, materials, etc. are not known:
1) Each vessel
2) Appears to apply to main seam welds only
3) Yes
4) 0.6mm material would appear to be less than the minimum thickness allowed by UG-16. Perhaps QW-150 and QW-160 can answer this question, I don't have convenient access to them
My feeling is that UW-12(f) is only applicable to butt joints, since Table UW-12 assigns lower efficiencies for other type joints, such as lap, fillet, etc.
Maybe someone else can shed some more light on this.
Regards,
Mike
RE: UW-12(f)
No other weld joints apply.
RE: UW-12(f)
Metengr, it applies to weld joints where E is NOT bigger than 0.80.
KOnrad
RE: UW-12(f)
If you read the entire UW-12, the "E" values in Table cannot be increased in value (please see UW-12 (a), (b) and (c)). The "E" values can certainly be decreased in value w/o RT as indicated in UW-12 (f). Please re-read this paragraph again.
RE: UW-12(f)
You are right, UW-12(f) doesn't affect E-factor. It has no provisions to make it higher or lower. It only gives requirements that pertain to welds which have E=<0.8. For my usual work- it covers all welds, except those, which do not have E. My concern is whether I have to conduct mechanical examination of testing plates that represent all welds in a vessel. The case is that I use a seamless shell- there's no longitudinal weld to test the prolongation of the main long seam. I cannot find anything that would limit this requirement only to longitudinal seam of the shell (or whatever else).
On the other hand- OK, I want to make such SIDE BENDING test on 1.5mm stainless shell. How do I do it? What do I prove with it?
Konrad
RE: UW-12(f)
which answers question 2
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RE: UW-12(f)
Konrad
RE: UW-12(f)
...A value of E not greater than 0.80 may be used in
the formulas of this Division for joints completed by any
of the "pressure welding processes" given in UW-27(a).....
So now that we have defined your welding process as a pressure welding process, read UW-9(a)which restricts this process to butt joints only.
Your question 2 asks if the test specimens required by UW-12(f) to prove the pressure welding process apply to fillet, edge or tube to tubesheet welds. And I say you cannot pressure weld anything other than butt welded joints based on UW-9(a).
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RE: UW-12(f)
Just one thing is still not clear to me:
...A value of E not greater than 0.80 may be used in
the formulas of this Division for joints completed by any
of the "pressure welding processes" given in UW-27(a).....
Wouldn't this imply that not all of these processes listed in UW-27(a) are "pressure welding processes", and UW-12(f) applies only to a subset of them?
Konrad
RE: UW-12(f)
Only those processes classified as pressure welding processes. see this link for a description of pressure welding processes: http:
In UW-27(a) arc welding processes are defined. In UW-27(b) other processes are defined and if you notice after "explosive" there is a footnote 6; defined as "welding through the application of pressure"
I am sure not all "pressure welding process" are listed here.
As far as your question 3, I would say that any material that cannot be represented by weldability per QW-150 and QW-160 needs to be tested.
As for question 4, I still don't know.
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RE: UW-12(f)
There are three kinds of people in this world; those who can count and those who can't.
RE: UW-12(f)
Does this story sound believable? It would solve my problem before I need to worry about making those tests.
Konrad
RE: UW-12(f)
Therefore, it is a pressure welding process and is also exempted from UW-12(f) specifically in the first sentence provided it is permitted by the rules in the applicable subsections.
Here is the first sentence of UW-12(f).......
A value of E not greater than 0.80 may be used in
the formulas of this Division for joints completed by any
of the pressure welding processes given in UW-27(a),
except for electric resistance welding, provided the welding
process used is permitted by the rules in the applicable
parts of Subsection C for the material being welded.
........and the remaining paragraph............
Test specimens shall be representative
of the production welding on each vessel. They
may be removed from the shell itself or from a prolongation
of the shell including the longitudinal joint, or, in
the case of vessels not containing a longitudinal joint,
from a test plate of the same material and thickness as the
vessel and welded in accordance with the same procedure.
One reduced-section tension test and two side-bend tests
shall be made in accordance with, and shall meet the
requirements of QW-150 and QW-160, Section IX.
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RE: UW-12(f)
Konrad
RE: UW-12(f)
Pressure welding- A nonstandard term for solid-state welding, hot pressure welding, forge welding, diffusion welding, pressure gas welding, and cold welding.
This is actually closing my problem.
Konrad
RE: UW-12(f)
htt
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