Guten Tag Shane! :-)
First of all, I have to apologize for the late response. I was on the road and had only restricted access to the net (BlackBerry).
Thanks a lot for your very interesting reply.
I must admit, what Jon as yourself have mentioned (ASME IX) appears to be quite "simpler" in order to know what kind of material thickness range is to be qualified and may thus be welded subsequently? U n f o r t u n a t e l y I have no access to the American codes or standards neither ASME nor AWS, what is a pity, since I often would like to "compare" both the US standardization as the European codes in terms of common paragraphs. But I remember what Joe Kane said once - most likely very appropriate (as usually) - /quote/:
"(...) I have worked as a consultant trying to figure out common denominators between several European codes and US Codes. In general there is no apples to apples comparison and conversions. It was always easier to re-qualify to the other code." /unquote/
I guess this says more than a thousand words.
However Shane, you have hit the nail again by having asked the question whether Cong's application does refer to a pure T-Joint fillet or a T-Joint (full or partial penetration) butt weld. This was overlooked by myself.
My example has referred to EN 287-1 pure T-Joint fillet and I have used the dimensions as been described within my post just by memory - hoping that even memory would have served me correctly.
Initiated by your last post however, I had a closer look again on EN 287-1 to check if I were right by having said, that with wall thicknesses and pure T-Joint fillet welds (single side welded) there is no distiction between the member's thicknesses, which would mean that the code won't allow to weld test piece having different wall thicknesses (just like Cong's application supposed us to consider).
And yes, it is as I thought that it was.
By having a look on Figure 2 (page 16) of 287-1, one can recognize that there is no differentation between the base- and the vertical member. Both thicknesses are determined by using the abbreviation "t", what's interpreted by myself as being t1 = t2. That - as been served by memory - I had meant was the reason for that EN 287-1 won't allow to qualify welders by welding test pieces having dissimilar member thicknesses with T-Joint fillets, but even to weld dissimilar test pieces showing the appropriate wall thickness for the particular range of qualification.
In terms of what I have tried to describe as an example of quasi "infinite" wall thickness qualification with the welding of (single side welded) "pure" T-Joint fillets, example 4 of EN 287-1 (page 29) can be used very appropriately.
This example describes a fillet joint test designated as:
- EN 287-1 111 P FW 2 B t13 PB ml -
It qualifies the welder as follows:
According EN 287-1 -- Qualification test of welders - Fusion Welding
Process Manual Metal Arc Welding = Shielded Metal Arc Welding acc. AWS = process number "111" acc. ISO 4063
P = Plate (for Plate Fillet) or even "T" (Tube Fillet) for tube diameters >= 150 mm
Fillet Weld (FW)
Material Group "2" acc. CR ISO 15608
Test piece thickness "t" = 13 mm -- thickness range of qualification >= 5 mm to "quasi infinite"
Welding Position "PB" (acc. AWS = 2F) = Butt weld flat and fillet weld horizontal-vertical*
ml = multi layer weld
* There is the range of qualification for the welding position designated as "horizontal-vertical" even though the welder has to weld in "PB" which is the horizontal position. If I would have been asked if a welder were qualified to weld in "vertical" position by just having welded a test piece in the "horizontal" position, I am honest, I have negated the question. Even since the old DIN 8560/61 welder qualification standard has required to weld a "vertical" position which would have subsequently included the "horizontal" position, but not contrariwise. However, as one can see, also this may appear as a question of interpretation. At least as I interprete it correctly, to qualify the welder for both positions just by having proved to be able to weld a "PB" (2F) position appears quite questionable. But I may be wrong and I have seen it incorrect what EN 287-1 shows even with this particular example (and the stated explanations).
However Shane, as EN 15614 even shows a distinction between "t1" and "t2" when describing the test piece for a T-Joint (page 9 of the code) my humble assumption was even that it were possible to weld test pieces having different member's thicknesses, even "t1" different to "t2" just as Cong has inquired. A situation which is not allowed by EN 287-1, as described above. Thus, so my assumption, wouldn't allow furthermore - as actually stated by 3.2 - to qualify welders according EN 287-1 for a particular thickness range in general, or even to qualify welders for a particular thickness range relating to a partciular thickness of one of both members of the T-Joint.
If however the latter were feasible and EN 15614 could be used for both qualifying both processes and welders (which is most likely the case), then, so my assumption, the "thinner" of both member wall thicknesses - as this is common practice with EN 287-1, namely, that "lower wall thickness includes larger wall thickness", would count for the welder's qualification range.
What now complicates the entire issue additionally is the fact, that a pipe branch connection (as to be seen in EN 15614 Figue 4 page 10) could - at least theoretically - show a larger wall thickness for thickness "t2", even though "t1" could show a lower wall thickness. In this case again, the welder would be qualified according to the greater wall thickness range - since the qualification range would refer to "t2" (branch pipe). And all this although he has welded also a lower wall thickness "t1" (main pipe).
Furthermore, as 3.2 says /quote/:
"(...) As i see EN 15614 there is no way to qualify a procedure with two different wallthickness..." /unquote/
I am asking myself, why is EN 15614 using the designations "t1" and "t2" if it won't be feasible to qualify different wall thicknesses. I truly suppose that this might be the reason for Cong to ask, which of both wall thicknesses - 10 mm or 20 mm - is the decisive one when welding a test piece having different wall thicknesses.
Nonetheless, it is as I said already, I am none but a layman with this. And thus I am convinced that an expert as 3.2 is surely right with his statement and interpretations of the standard. That is, if EN 15614 shows no way to qualify different wall thicknesses, then this is certainly the case and all what I have stated herein is worthless anyhow. This however, were absolutely no problem for me, as long as the issue will be clarified finally and I would have been allowed to have learned something new.
It is as you have so wisely spoken, as you wrote
"...It would help if Cong came back and told us exactly which joint he is meaning. .
I must apologize Shane, for not knowing AWS D 1.1 and the regulations within this - most likely very interesting - code. Perhaps one of the other appreciated forum fellow members could clarify the situation by doing shed some light on this.
Finally, I have heard that there should come a successive standard for EN 287. This should be an ISO standard. However, I have no detailed information in terms of if this is true. If however it were true, then... hmmm... I'm afraid that it will be... confusing?
Thanks again and my best regards,
Stephan
Edit: Had forgotten a comma and to exchange a "greater" by a "lower". Huuuh... what confusing! :-)