Visual criteria for welder test

[PAN]

I have tried to find the related subject. I find only thread292-132309 .

Refer to ASME IX QW-194, I cannot find the clear criteria for complete joint penetration with complete fusion of weld metal and base metal.

Should I refer to the criteria in ASME B31.3 Chapter VI Table 341.3.2 for welder qualification? Please comment.

 

[gtaw]

I typically apply the visual acceptance criteria of the construction code that will be used.

The visual criteria provided for in Section IX does not address the typical weld discontinuities that would be evaluated in production. It creates a situation where, if only the criteria of Section IX is applied, a welder can be qualified but still be incapable of meeting production requirements.

It's a bit of my philosophy that the welder's qualification test should be on the same order of difficulty as the production welds. This in no way violates ASME code requirements. After all, ASME code requirements are the minimum requirements that have to be met. They are not the optimum or maximum requirements that have to be met.

If the welder can not meet the production requirements under the ideal conditions of the “testing booth”, how can he/she be expected to meet them under actual production conditions? It is more efficient to weed out the poor welders than to repair production welds (unless you are working with a “cost plus” contract).


Best regards - Al

 

[PAN]

I found the related subject in this link.

http://www.aws.org/cgi-bin/mwf/topic_show.pl?tid=8677

I agree with gtaw's comment. However, my contractor insists me consider the difficulty to find qualified welders in current market situation. It seems that they do not want to meet criteria for concave root surface and weld reinforcement/internal protrusion. Is this the practical way to follow ASME IX? Please comment.

 

[gtaw]

I don't remember the details of the television advertisement, but it was for oil filters and the message was; "Pay me now or pay me later!" Of course they were selling oil filters and you either changed your oil filters or paid for an engine rebuild later.

Qualifying welders is similar in that you either weed out the welders that don't have the necessary skills or you pay the premium required to repair the unacceptable welds and live with the schedule slip due to repairs. There is also the reputation of the contractor to consider, once the contractor's reputation is sullied, it difficult to change it in the eyes of the client.

I would rather be selective up front than to have to explain high reject rates to the client.

Skilled welders are available, but as is always the case, you have to pay for quality. One way or another you will have to pay. The construction code's acceptance criteria will have to be met. It can be the first time using qualified welders, or after the first, second, or third repair, or by the contractor that will replace the non-performing contractor.


Best regards - Al