In this article, I have discussed some fundamental aspects of a Welder Performance Qualification in accordance with ASME Section IX. The article begins with some of the very basic questions such as what it means to qualify a welder, why should a welder be qualified at all, how to document a welder’s qualification etc.
The article progresses in complexity gradually, addressing finer and deeper aspects related to a welder’s qualification, such as tests required for qualifying a welder, qualifying multiple welders through the same coupon, welder’s qualification through a procedure qualification coupon, groove dimensions of a welder’s qualification’s coupon, and so on.
Of course it is difficult to address all the aspects related to this subject within one article. So there are a number of articles, approximately 20, on this website, wherein I have covered nitty-gritty of this subject, and some insights gained through own experience on various matters surrounding a welder’s qualification. The links of some of these articles can be found within this article at relevant places.
Before we proceed further, please note that the terms ‘welder qualification’, ‘welder performance qualification’, ‘performance qualification’ all mean the same thing, and have been used interchangeably in this article, as well as other related articles on this website.
What Is ASME Welder Qualification?
Simply put, welder performance qualification as per section IX means qualifying a welder in accordance with the rules of ASME BPVC Section IX. Article III of Section IX is dedicated to the subject of Welding Performance Qualifications, and lists in complete detail all things related to it.
In Section IX, the Article III elaborately discusses variables and rules that govern how a welder should be qualified (for example, what coupon size should be taken, what all tests need to be done, etc.), in what all places that welder can be deployed while being in compliance of Section IX, when does the validity of his qualification expire, and how to renew it.
When a welder gets qualified in accordance with Section IX, he becomes eligible to weld on all Coded jobs that refer Section IX for the purpose.
Why Should A Welder Be Qualified In Accordance With Section IX?
The welders in my shop are highly experienced. They are qualified in accordance with a national statutory standard. These welders do extensive welding on all kinds of challenging jobs, which makes me believe that they are fairly capable and qualified. Why do I need to qualify my welders as per ASME Section IX then?
If these questions rose in your mind when you started out as a welding engineer, but were too sheepish to ask such questions to a senior, don’t worry. These are not silly questions. I found myself asking such questions too. Knowing the answers to these questions definitely helps.
First up, the various Codes of constructions like ASME Section III NX, Section VIII etc. require welders qualified in accordance with Section IX. For example, NX-4321 of Section III NX requires that all Welder Performance Qualifications should be in accordance with Section IX.
These Codes of Construction are generally contract requirements or statutory requirements, so compliance to Code of construction is mandatory. Therefore, qualification of welders in accordance with Section IX becomes imperative to stay compliant with contract/statutory requirements, regardless of the welder’s existing qualifications to other national standard(s).
If the jobs in your shop are manufactured in accordance with a National Codes or International Codes (other than ASME BPVC), or specific customer requirements that do not specifically require welding qualifications as per Section IX, then you need not qualify your welders as per Section IX.
Secondly, from a logical point of view, a welder may be highly experienced, and skilled. But then, skill is a subjective word. When you are welding a critical weld in a pressure weld, you would want to be absolutely sure that the welder is good enough. You need a validation (backed up by a Code) that would allow you to authoritatively say that the welder has requisite skill.
Thankfully, we have such rules and stipulations in the form of Section IX that permit us to judge whether a welder is good enough for a particular job or not. The welder performance qualification tests done in accordance with Section IX judge the ability of a welder to deposit sound welds.
If the welder’s test coupon passes the acceptance criteria laid in Section IX, he is considered qualified to weld on Coded jobs that require Performance Qualifications to be in accordance with Section IX. There are different kinds of qualifications defined in Section IX, such as groove weld test coupon, fillet weld test coupon, corrosion resistant overlay coupon, and so on.
A welder, on passing the requisite criteria of a qualification, can weld on jobs within the boundary of essential variables defined for the qualification. The essential variables are listed under QW 350 for welders, and QW 360 for welding operators.
Alright, so it is understood that any welder making a weld on Coded jobs needs to be qualified in accordance with Section IX. What about the helpers assisting the main welder? Do they need to be qualified too? Get to know the answer to this question here.
Do I Need A Qualified WPS To Qualify My Welder?
Yes you do. As per rules of Section IX, you need a qualified WPS for qualifying your welder. Alternatively, you can also use a standard WPS (or SWPS) listed at the back of Section IX.
You cannot qualify a welder with a provisional or ad-hoc WPS. In other words, it is not permitted to weld a performance qualification test coupon following a set of variables other than a qualified WPS or SWPS. This has been further attested to by the Committee in the Interpretation IX-16-17.
A welder qualified with one qualified WPS can then weld with any other qualified WPS as long as he remains within the limits of essential variables of QW 350.
But I have just started my work shop. I do not have a qualified WPS in my hands. How do I go about qualifying my welder then?
Well, for doing ANY production weld, you need a qualified Procedure (in other words, a qualified WPS). So, assuming you are going to do a production weld in your shop, you would need to qualify a Procedure Qualification. Section IX permits you to combine Procedure Qualification and Welder Qualification, as given in QW 301.2.
This article later on discusses in some detail about covering the welder performance qualification through procedure qualification.
Note: If your Code of Construction requires Lot Qualification of the welding consumables too (Section III NB does), then you can think of combining all three in a single coupon too. That is, the Procedure Qualification, Welder Qualification, and Lot Qualification can all be combined into a single coupon.
For this, you must smartly choose your variables such that you satisfy the requirements of all three.
Alternatively, you can use a Standard WPS listed in Appendix E of Section IX, for qualifying your welder.
Once a welder gets qualified using a qualified WPS, can he weld with only that WPS on the production job?
No. A welder qualified to weld in accordance with one qualified WPS can weld on job with ANY other qualified WPS, within the limits imposed by QW 350 or QW 360.
This goes for extension of validity as well. Engaging in a welding process using a WPS extends his validity for that process (not just that WPS). In other words, his validity gets extended for welding with ANY other WPS having that process. This finds confirmation in the interpretation IX-83-166.
How To Qualify A Welder In Accordance With Section IX?
A welder can be qualified in accordance with Section IX by welding on a test coupon, and subjecting it to the requisite testing. This article later covers the type of tests required for qualification of welders.
Alternatively, a welder can also be qualified by doing volumetric examination of the initial production weld made by the welder and applying the acceptance criteria for volumetric examination given in QW 191.
Section IX allows making use of production assembly mock-ups too, for qualifying a welder. This article later discusses in some detail about doing a welder’s qualification through production assembly mock-ups.
The type and size of the test coupon have to be decided keeping in mind the application on which the welder would be deployed on. For example, a welder engaged only on fillet joints can be qualified by preparing a fillet weld test coupon, and subjecting it to the testing of QW 452.3
The base metal grade and thickness chosen for making the performance qualification coupon must be decided based on some rules. Read this article for some interesting insights on choice of base metals for welder qualification.
Section IX is pretty liberal when it comes to qualified weld metal thickness for welder performance qualification. If a welder has deposited at least 13 mm with a minimum of 3 passes in the qualification coupon, and the coupon passes requisite testing, the welder gets qualified to deposit unlimited weld thickness. There is no restriction on lower side.
If the welder is going to be deployed on jobs requiring corrosion resistant overlays, then the qualification coupon must be prepared and tested in accordance with QW 381. A welder qualified on groove weld test coupon also is qualified for doing such overlays if the production WPS does not have a chemistry requirement specified on it.
If the overlay is to be done on a pipe, then there are some things to keep in mind as well. There are several stipulations surrounding welder qualification for claddings, which, for the sake of covering in some detail, I have covered in another article. Here is the link.
How Do I Document A Welder Performance Qualification?
Section IX does not impose any particular format in which the welder qualification must be documented. You can use any format that is convenient to you. But your format must record all the essential variables (as per QW 350 or 360) that were used in the qualification test, and the ranges of qualified variables, and the results of mechanical/visual/volumetric NDE.
You can generate this document as a one-time certificate; attest it with a seal of the appropriate authority. You can preserve a copy in the official documentation, and perhaps share a copy with the welder for record and safe keeping. This record must be presented to the authorised inspector, whenever asked, to demonstrate the organization’s compliance with Section IX.
Section IX suggests a recommended format at Appendix B, QW 484A/ QW 484B, which you may make use of for recording the qualification test of your welder. This format is a recommendation, a suggestion. One does not have to follow it mandatorily to demonstrate compliance with Section IX.
In my opinion, this format given in QW 484A is the best; most succinct format one can imagine of, although, in my organization, we use a different format.
Content Of A Welder Performance Qualification Record
Although Section IX does not impose any particular format for documentation of a performance qualification, it does state what information needs to be documented. This is addressed in QW 301.4, the following four things must be recorded for a welder (or welding operator) performance qualification:
- Essential Variables of QW 350 (or QW 360: for welding operators).
- Tests done (such as visual, bend, macro examination, fracture tests, radiography, UT, etc.)
- Results of the tests done.
- Ranges qualified by the qualification.
The above information regarding what needs to be documented on a welder performance qualification record is also addressed in QG 104.
What Needs To Be Documented?
Any organization that does welding in accordance with ASME BPVC Section IX must generate and maintain record for –
- Fresh Welder Performance Qualifications, as per QW 304/QW 305.
- Qualification done to renew the expired validity of a welder’s qualifications, as per QW 322.2 (a). See Interpretation IX-83-154 (Qs 3) for reference.
- Maintaining the continuity of a welder’s qualification through his engagement in welding with that process, as per QW 322.1 (a).
The document(s) that records ‘i’ and ‘ii’ above are meant to capture information about what happened during a qualification. The minimum information that must be included in such a document is indicated in QW 301.4. These two documents are generally static documents. That is, once they are generated and attested, they get stowed away as permanent records.
The document(s) that records ‘iii’ above contains evidence of welder’s engagement on a weld using the process for which he is qualified. This document also primarily indicates the date up to which a welder is authorised to weld. Before this date expires, the Record must be revised to indicate fresh data that would prove a welder’s engagement with that process.
The revised document would then indicate the new date up to which the validity of the welder’s qualification(s) has been extended. This document is thus, dynamic, and gets revised once approximately 5-6 months.
In my organization, all the three records described above get signed and stamped by the authorised inspector.
These records can be asked at any time by Authorised Inspector as a proof of a welder’s eligibility to weld on a Code-related job. These records may also be asked during certification/renewal audit of a Certificate Holder. Such records help in demonstrating an organization’s compliance to Code in manufacturing activities.
What Are The Tests Required To Qualify A Welder?
Generally, Section IX requires either volumetric NDE (any among UT or RT is fine), or, mechanical testing and visual testing to qualify a welder.
If you choose the volumetric NDE option (which is what I choose whenever possible, since it involves less hassle), you must cover at least 150 mm of weld deposited. Remember that if the test coupon is a pipe, you must cover the entire circumference of the coupon, even if the circumference exceeds 150 mm.
If the coupon is of very small diameter, you can use multiple coupons to fulfil the 150 mm rule above. However, in such cases, you need not use more than 4 coupons.
The NDE has to be done as per QW 191.
An advantage of choosing the volumetric option is that if you have sufficient confidence on the welder, you can deploy him directly on the job, and test the first 150 mm deposited by him with RT or UT. Section IX permits this in QW 304.1. It is useful if you are pressed for time.
If you choose visual and mechanical testing option, the requisite testing has to be done in accordance with QW 302.1 and QW 302.4. This option will require completion of welder’s qualification before his deployment on the job (and not in parallel or later to the job), because most of the Construction Codes are particular in saying that only a qualified welder must engage on the production joint.
Once a welder passes the acceptance criteria required by QW 302, he can then be deployed for production welding on job. If he does not pass one or more tests, there is provision in Section IX for immediate retesting as well for the failed tests.
Read more: Retesting in Welder Qualification
Validity Of A ASME Welder Qualification
Once qualified, the validity of a welder’s Performance Qualification remains in force for six months. The validity gets extended by an additional six months if the welder has welded with that process within the period of validity. The validity gets revoked if there is specific reason to question his ability.
I have written another article that addresses aspects such as date of start of validity, the type of jobs that a welder needs to engage on for extending his validity, number of times that validity can be extended for, possible criteria for revoking a welder’s validity, and so on.
If the validity gets expired, it can be renewed by welding a coupon in accordance with QW 322.2. I have written a separate article addressing the renewal of an expired welder qualification as well. There are some insights that I think are worth knowing. The article can be found in the link.
Groove Dimensions Of A Welder Qualification Coupon
Sometimes we completely overlook groove dimensions of the coupon being designed for a welder qualification. The edge preparation details are a non essential variable for Welding Procedure Qualification. Hence they are generally overlooked.
Section IX recommends certain groove dimensions for a welder qualification coupon in QW 469.1 (for welds with backing), and QW 469.2 (for welds without backing). Alternatively, the groove dimensions can be same as those of any WPS qualified by the organization.
A welder qualified with backing is only eligible to weld with backing, while a welder qualified without backing is eligible to weld with backing and without as well.
Performance Qualification Through Production Assembly Mock-Ups
For performance qualifications done on fillet weld test coupons, QW 181.2.1 says that a production assembly mock-up may be used in lieu of the standard coupons defined in QW 462.4(b) or QW 462.4(c).
An Interpretation IX-10-05 dealt with the subject of use of production assembly mock-ups in lieu of standard coupon. The Interpretation rules that for a welder qualified through a production assembly mock-up, a change in base metal thickness, or fillet size, or mock-up configuration, will require requalification of the welder.
These variables are not essential variables for welder qualifications. Why would the Interpretation say like that then?
See, a production assembly mock-up is non-standard, from the view point of Section IX.
QW 462.4 (b), QW 462.4(c) contain certain requirements, such as length and width of the joining members, thickness of the two members, maximum fillet size etc. Each of these stipulations, however trivial they might seem, have some thinking behind them, and have been deliberately and consciously specified.
Due to whatever reasons, for your welder’s qualification, you might not want to, or might not be able to make a test coupon meeting these requirements.
This could be because the Inspector might want the test coupon to simulate the actual job configuration, and actual job dimensions. You would then have to mimic the production joint in the test coupon (which is what a production assembly mock-up is).
Or, sometimes, you might be plainly short on the raw material meeting the size requirement of QW 462.4(b), QW 462.4(c). In such case too, you might end up having to qualify your welder through a production assembly mock-up.
Now, the production assembly mock up might in actual be on par with the test coupon of QW 462.4(b) or (c). But Section IX does not know that. Hence, Section IX places a restriction on the qualified ranges of a welder qualified through such mock ups.
The qualified range of such a qualification is limited to the fillet sizes, base metal thickness, and configuration of the mock-up. This has been specified in the General Note under QW 452.5.
Why is a production assembly mock-up specified only for fillet weld qualifications? Why not groove welds?
See, for groove welds – a production weld alternative has been given in QW 304.1. That is, a welder can be qualified by doing a volumetric examination (as an alternative to mechanical testing done on a test coupon) on the first 150 mm deposited by the welder on the production joint itself.
For a fillet weld test coupon, volumetric NDE is not a practical option. Hence, Volumetric NDE has not been specified as an option by Section IX for qualification of a welder through fillet weld coupon. A welder qualification done through a fillet weld coupon must therefore undergo destructive testing (fracture test and macro examination).
Hence, the qualification can only be done on a non-production joint coupon, that is – either a standard coupon specified in QW 462.4(b) or (c), or the production mock-up discussed above.
Performance Qualification Through Procedure Qualification
QW 301.2 affirms that a welder who prepares the Procedure Qualification coupons gets qualified for Performance Qualification too. This is commonly understood everywhere.
The authorised inspector in my company too recognizes the welder qualification obtained by welding on a Procedure Qualification coupon (which passes all the tests stipulated for a Procedure).
But, on one condition. All the tests required for Performance Qualification should have got covered in the Procedure Qualification. Only then the welder is deemed to have got qualified.
Now, QW 301.2 does not lay out any such condition. It merely says that “…a welder who prepares the WPS qualification test coupons meeting the requirements of QW 200 is also qualified…’’.
What does the Section IX intend? Is it required that all the tests specified for a Performance Qualification must necessarily get covered in the Procedure Qualification coupon for the welder to get qualified?
For groove weld coupons, the question is largely redundant. The tests required for Performance Qualification get automatically covered in the Procedure Qualification. However, for fillet weld coupons – there is a difference.
QW 451.3 requires only macro examination for qualifying a Procedure. On the other hand, QW 452.5 requires macro examination and Fracture test, for a Performance Qualification.
So, is the welder that prepared the test coupon for the fillet weld Procedure Qualification qualified?
The answer is yes. The ASME makes clear its intention in this regard, through the Interpretation IX-83-31. Although, the 2021 edition of Section IX has introduced a caveat in this regard. A welder who gets qualified by virtue of having prepared the fillet weld procedure qualification test coupon is only qualified to weld on non-pressure retaining fillet welds.
Another relevant interpretation is IX-18-48 that asks precisely the above question. The ASME’s reply reflects the above understanding as well.
So this was, in brief, about welder performance qualifications in accordance with Section IX. Please do leave your thoughts below in the comments section.
If you are a beginner, and wondering how to locate ASME Interpretations, here is a link.