All of us agreed that the Code must be known first for us to provide an accurate answer. I have mentioned that earlier.
I do not dispute this statement
Okay let say the actual code is API 1104 ; azphiks’ welders were qualified in 1”dia OD butt weld (6G), he wants your advise if these welders are qualified to weld 1/2" dia socket weld. --- Yes as long as no essential variables are changed.
6.2.2 Scope
A welder who has successfully completed the qualification
test described in 6.2.1 shall be qualified within the limits of the essential variables described below. If any of the following
essential variables are changed, the welder using the new
procedure shall be requalified:
6.2.2.f. A change in position from that for which the welder has
already qualified (for example, a change from rolled to fixed
or a change from vertical to horizontal or vice versa). A
welder who successfully passes a butt-weld qualification test
in the fixed position with the axis inclined 45° from the horizontal
plane shall be qualified to do butt welds and lap fillet
welds in all positions.
This paragraph seems to say that a welder is qualified for fillets if he successfully passes a 6G butt-weld qual. (single), However it will still be held to the other essential variables found in 6.2.2 such as Joint design, welding process, direction of travel, OD groups, Wall thickness groups, filler metal groups. Test Coupon = 1" dia. xxs (0.358") will not qualify a 1/2" dia. Std. wall (.109") due to change in wall thickness groups (essential variable)
Do you agree with Mr Curtis Stewart, that the welders must go for multi qualification and not a single qualification? You don’t mind to elaborate on why you said “it gets worse if we assume a single qualification”
6.2.2.f - Allows for fillets qualified by butt-weld test if welded in the 6G position as I read it
Elaborate - I mean to say that the multiple qual. test is a broader qualification and therefore if we were to assume what test the OP used, that would be the best scenario to use as his welders would be qual'd for the 1/2" socket welds (within limits), VS a single qual. that has a narrower range of qualified positions, sizes, etc...
I don’t have my API 1104 with me ……but I still do remember in my past project when we want to weld some drain pipes (3/4” dia socket welds)…we only qualified our welders in single qualification (using 60mm OD pipe ; GTAW process). Have you heard outside diameter grouping in API 1104?
I agree that this can be done. Do you remember if the coupons were welded in 6G position?
Yes I have heard of OD grouping in API 1104 but that is not the only essential variable and piping may fall into the same OD group but not the same Wall Thk. group
As I said before this is my understanding of the Welder qualifications per API 1104. I am open to correction if I am misinterpreting something. My intent is not to prove/disprove or argue anything other than the OP must provide additional information as the test variables will affect the qualification