Thickness Qualification under Section IX

[carbonear59]

Recently while reviewing Welder Performance Qualification Cards I noticed what i believe are incorrect thickness ranges listed on these cards . My understanding is that the maximum thickness qualified as per Table QW452.1 (b) using radiagraphy is 2t,(twice the deposit thickness for each F#),I think the problem is that the 'maximum to be welded 'in the Table referenced above is being misinterpreted to mean the welder is qualified to an unlimited thickness and by doing so the intent of the code is being missed .
Any comments/clarification would be greatly appreciated .

 

[CodeRef]

According to Table QW-452.1(b), the minimum thickness that a welder has to deposit in his test coupon to be qualified for unlimited thickness is 1/2 in, and that thickness must contain at least three weld layers.

Read the following link for a detailed explanation:

http://www.sperkoengineering.com/html/articles/2002_addenda.pdf

 

[weldtek]

Max to be welded would then be limited by the qualified WPS. As an example, if you successfully test a welder on the SAW process on 1/2" thick plate depositing at least three layers, and have a WPS qualified to 8" weld thickness, this welder is qualified to weld through 8" thickness.

 

[carbonear59]

Thanks CodeJackal , I understand what you are saying and Mr.Sperko's article is informative as well . The problem i am having now is this ; Ordinarily when ASME uses a number as a cutoff point (as in QW 452.1(a))it is written explicitly (eg less than 1/2 , greater than 3/4 etc.). This makes me wonder if the conditions listed in QW 452.1(b) should be read together , not individually . For example ; if a test coupon is .625"(5/8)and welded with F3 to 1/8 then filled with F4 to 1/2" ,then the welder is qualified up to 1 1/4 . However if the coupon is .750 and the ticket then gets written for unlimited thickness the (2t) requirement for ALL thicknesses in QW 452.1(b) has been busted .
Given this , is it not possible that the intention of the Code is to allow a welder to weld from X " to 1 1/4 " Then above this thickness it would be necessary to meet the (2t)requirement ? Under this scenario both thickness requirements of QW 452.1(b) can be met.
I realize this could be totally wrong , what do you think ?

 

[carbonear59]

Thanks Weldtek , the problem i am having with your reasoning is this , 452.1 (b) say Max to be welded not max allowed by procedure .(obviously you can only use the thickness qualified on the procedure ). This is the crux of the issue , read individually these clauses are easy , makeing them work together because there is no less than ,equal to or greater than qualifier as is usually the case in ASME is my problem .
What do you think ?

 

[metengr]

carbonear59;
You must read the Notes in Table 451.1 applicable for each column. The Notes refer to variable restrictions.

 

[metengr]

carbonear59;
Correction, that should be 452.1., and most important you need to review Article III, QW-300.2. You cannot cherry pick information in Section IX from the Tables without understanding the accompanying Articles.

 

[carbonear59]

Fair enough , didnt want to cherry pick , just wish the table read < 1/2 and >/= 1/2 , instead of ALL ,thanks for the info .

sf

 

[CodeRef]

The subject of "t" as used in the QW-452.1(a) table is the total weld metal thickness deposited by all welders and all processes in the test coupon, whereas the subject of “t” as used in the QW-452.1(b) table is the maximum thickness that an individual welder is qualified to deposit in production based upon separate values of “t” determined by process, F-number and QW-404 essential variable.

In the QW-452.1(b) table, the difference between the two noted restrictions is the deposit (and documentation) of the three weld layers, within the individual QW-404 variables. Welders have the ability to deposit greater than ½ inch in less than three layers, thus the reason for separation for qualification within the table.

 

[carbonear59]

Thanks again folks , i have another related question , we are using 4 different welding procedures (all properly approved ) on this particular job . Two of these are F3/F4. the difference is qualified thickness /preheat and postweld heat treatment requirements . the welders have PQR cards that read 'max to be welded /unlimited etc.' my contention is that Section IX still requires us to 'job test ' these guys to EACH procedure even though they are both F3/F4. the counter argument i recieve is that under QW 301.2 we are only required to prove the welder can weld to the SMAW process , the fact we use different procedures is irelevant . any guidance would be appreciated .
the next question is this; i am also being told it isnt necessary to have the qualifying RT shots read to Section IX . the belief being that if they are read to the Code of Construction that qualifies the welder . I disagree with this . Again any guidance would be appreciated .

 

[metengr]

quote]my contention is that Section IX still requires us to 'job test ' these guys to EACH procedure even though they are both F3/F4. the counter argument i recieve is that under QW 301.2 we are only required to prove the welder can weld to the SMAW process , the fact we use different procedures is irelevant [/quote]

There is no job test for Section IX. Welders are qualified by essential welding variables per Article III by process. A qualified welder can use multiple welding procedures provided all essential variables are documented and the procedure selected for the job does not fall outside of the welder performance essential variables.

i am also being told it isnt necessary to have the qualifying RT shots read to Section IX

It is necessary to have the RT acceptance criteria as per Section IX, See QW-302.2 and QW-191.

 

[carbonear59]

Thanks again Metengr , i put job test in quotes on purpose . your answer to the second part of my question is very clear . With respect to the first part ,would it be fair to say that if we (the company i work for ) dont document a procedure on a form ( for simplicity ; the suggested one in Sect. IX ) combined with either acceptable visual/mechanical results OR an RT shot read to SECT IX criteria ,then the welder is not qualified to weld under Section IX . once again i want to thank you for helping me with this . i really just want to know how to apply the Code correctly .

steve

 

[metengr]

Steve;

With respect to the first part ,would it be fair to say that if we (the company i work for ) dont document a procedure on a form ( for simplicity ; the suggested one in Sect. IX ) combined with either acceptable visual/mechanical results OR an RT shot read to SECT IX criteria ,then the welder is not qualified to weld under Section IX

Correct.

 

[pipewelder1999]

Forgive me if this repeats something that has already been addressed.

The requirements for performance and procedures are completely seperate and apart. The only thing related to a procedure for perfomance qualification is the fact that one has to be used.

A welder could use a single procedure for performance qualification and not be able to use that procedure in production depending upon the conditions of the production weld.
A welder in fact could perform all of the welding on a PQR and be both qualified outside the range of the WPS and not qualified for certain ranges on the WPS.

Also , in most cases SEC IX is the acceptance criteria for performance qualification however in cases in which qualification is allowed on production welds, the acceptance criteria is the code of construction.

Gerald Austin
Iuka, Mississippi

http://www.weldingdata.com

 

[carbonear59]

Thanks pipewelder , i thought i had this nailed , however i am glad you responded . i understand that procedure and performance qualification are different animals , however my confusion is this ;Welder 'A' is in possession of procedure qualification card which allows him to weld 'max to be welded ' i also have a document that tells me welder 'A' is qualified to weld to Company procedure '1' which is your standard F3/F4 procedure without PWHT. we naturally have procedure '2 ' that has a higher preheat' different interpass and PWHT. requirements . so now the question is this ; is my company required to document that welder 'A' is qualified to use this procedure ? If yes is the answer please tell what i have to do . i am also confused between your statment that the code of construction is the correct way to go and metengr's response that Sect IX criteria should be used . Look forward to hearing from both of you . many thanks

Steve

 

[pipewelder1999]

One of the most confusing issues that I see is reference to a welder being qualified to wps.

A welder in possesion of a "procedure qualification card" in and of itself is very confusing. There is no such reference made in codes.

Because procedure and performance qualification rules differ it would be very confusing to refer to one from the other.

I would take the reference to welders being qualified to procedures (WPS's) completely out of your system and then on any documentation related to welder performance, address only the variables needed for performance.

Its my opinion that the whole referring to a WPS for performance qualification is a thing that was started t o minimize how much superintendents and supervisors had to know about code requirements and minimize the time on a project for QC. Just my opinion.

For performance qualification for SMAW there are 7 variables that need to be addressed. Pretty simple but to someone wanting to pick and choose welders from a list, this makes it easy but misleading.

One advantage of using software for trcking WPQ's is the fact that retrieval based on production conditions is very easy. Some software may even refer to WPS that welders are qualified for. That is again, misleading.

I hate going to a shop and getting an index of welder qualifications by WPS when all I needed was there ranges qualified. I then compare the welders to what is being done in production. Seperate and apart, I verify that the WPS's and supporting PQRS's are correct.


Gerald Austin
Iuka, Mississippi

http://www.weldingdata.com

 

[pipewelder1999]

I forgot to address the question regarding production qualification and was partially incorrect .

QW-191.2.3 Production Welds. The acceptance
standard for welding operators who qualify on production
welds shall be that specified in the referencing Code Section.
The acceptance standard for welders who qualify on
production welds as permitted by QW-304.1 shall be per
QW-191.2.2.

Of course then you may get into an issue where the production weld is acceptable and yet the welder is NOT qualified ? HMMM

Gerald Austin
Iuka, Mississippi

http://www.weldingdata.com