And a great presentation coming from Mr Walter J. Sperko, this to say the least.
Outstanding effort in pointing out that there is a distinct difference between 'welding test positions' like excellently shown by Lawrence and explained by the others, and the daily job reality.
According to your statement:
"...using the terms 1G, 2G, 4F etc are wrong for the range qualified. It mean to say FLAT is not equal to 1G, HORIZONTAL is not equal to 2G/PC and so on...
I would interpret the bottom line of the very detailed explanations within the PPT as follows.
• There are a few core sentences like:
1. Test positions are discreetly defined positions of test coupons that are used when testing welders
2. These positions have tolerances of +/- 15° from the defined horizontal planes and +/- 5° from a defined vertical or inclined plane
And the most crucial one is – from my humble point of view – the assessment:
3. Make sure that code users understand the difference between testing positions and production welding positions
In my understanding this expresses the reality in welder qualification. In other words. To qualify a welder for a different welding position, one has to define the range of where a particular position (e.g. 1G = PA) has to begin and where it has to end, so to speak. This again is done by defining the position of the test coupon(!)
within a coordinate system, which can be described by defining the solid angles. Exactly this has been performed by the tolerance ranges like mentioned above (item 2).
The rest is relatively simple and hopefully I’m right seeing it this way. Why?
Hmmm… because the welding positions to be performed in the daily job are much more complicated. Surely there are ‘true’ 1G,… positions matching exactly the welder qualification by matching exactly the tolerance ranges as described above. But very often, and hopefully you will agree, the daily job welding is confronted with welding positions in between the welder qualification ranges. This is how I understand Mr Sperko’s statement: Because of tolerance limits on test positions, positions in between test positions are undefined!
Whereas the former, i.e. the test positions, are defined by – please correct me when I’m wrong, since I am not familiar with these codes – the code(?) QW-120, which apparently describes the conditions as above, the latter, i.e. the production positions, are translated from these ‘test conditions’ into the ‘transition positions’ by code QW-461.9.
Since the ‘production conditions’ however, are very often not equivalent to the ‘test conditions’ to be performed by the welder, the assessment is correct saying: “Flat is not equal to 1G”
, or “Horizontal is not equal to 2G(PC)”
And the rest of the presentation is very accurately explaining these transitions between the ‘test positions’, necessary to qualify the welder in an appropriate way to the daily requirements, and the ‘production conditions’ existing in between the ranges the true test positions are representing.
Or, to keep all this in a nutshell: There is very often a difference between the 'test position' and the 'production position'. Both are described by different conditions and this again is the reason that a 'production' 2G is often not equal to a 'test' 2G position.
So far my humble .02$.