Radiographic trend tracking

Date 02-22-2007 21:46

What trend are you referring to. The accept/reject is stated in API 650 6.1.5 which refers to Paragraph UW-51(b) Section VIII ASME and 6.1.6 gives the Determination of Limits of Defective Welding. I don't know of anyone tracking industry rejection rates as all rejects must be repaired. My experience with one or two (maybe three) contractors is a welder gets 4-5 floor repairs and 2-3 insert/plate repairs then they get retrained on the location of the entrance gate.
BABRT's

By CWI555

Date 02-23-2007 03:56

What I gather from the two answers given, is there is no written standard. I realize the question seemed a bit odd, and no I am not aware of anyone tracking industry rejection rates. The question was more meant towards is there a written standard for trend tracking on a project. Opinions are flying around the project I am on. There are just under 9,600 meters (6 miles) of weld to be made with 100 percent RT and 1/3 of that number to be UT'd as well, with an additional 24,000 meters of non-RT weld to be testing by surface methods. If you had to trend track that volume of weld for reject rate, how would you go about it.

By dbigkahunna (****)

Date 02-23-2007 12:13

HMHO Only. By the meter. But what do you want to do with the information. Establish bonus pay for the welders, project, company? determine if there are welding issues as the project progresses? If in the first 100m of weld there are no rejects, then you can assume the remainder can be welded w/o rejects. This is interesting as I have only seen rejects on tank erection projects used to, uh, terminate welders. And each project has it own set of challenges, so a firm set guideline for one project would not necessarily work for another. And establishing one set for shop fabrication could be too strict for field work.
BABRT's

By hogan

Date 02-22-2007 22:09

i've seen it by the inch, and by the weld. i haven't seen it by the radiograph

By nosetackle (**)

Date 02-23-2007 12:07

As far as i know there are 3 methods applicable,

Joint wise
Length wise
and Number of RT films used.

the most fair one for welder is calculate the welded length and repaired length and get the ratio.
the most unfair one is joint wise, count the welded joints and repaired ones and get the ratio.
the film wise is a a bit strange for me.but i have seen applications on it. count the number of films used. and count the films on which there are defects. and get the ratio. for sure this is not for roll films.

all these methods can be applied. but the main thing is project requirements. it is not possible to find a method or acceptance/rejection ratio in any standard. it is totally related with customer satisfaction.

Regards,

T

By CWI555

Date 02-23-2007 16:45

To all who answered,

I did not expect that there would be a standard method in writing. I am a bit dumbfounded that an individual here made the statement that there was standards. Of course when ask what those standards were no answer was forthcoming. It was a agreed by the owner and manufacture to go by the film given the nature of the project. (and no it's not roll film). There are a multitude of ways to go about it, by the film works, by the weld does not in my opinion. I had to ask the question, and I get similar responses everywhere I've ask.
Thanks for your replies.