This issue has come up before.
I don't have a copy of D1.1 as I sit in the airport lounge, but I'll toss my opinion (not my interpretation;)) into the ring anyway.
I may have it wrong, but my recollection is that D1.1 states that CJP welds made with backing are qualified for CJP welds made with backing gouging. However, it does not say that welds made with back gouging are qualified for welds made with backing. Its a one way street, no vice versa is involved.
The tables in Section 4 indicates a CJP groove weld qualifies the welder for fillets as well as CJP groove (with conditions attached as indicated by various notes). In the body of the text, and I don't recollect where, it states that a CJP groove weld also qualifies the welder for PJP groove welds.
So, bottom line:
A welder qualification test consisting of a CJP groove weld made with backing qualifies the welder to weld fillets, PJP groove welds, CJP groove welds that require back gouging, and CJP groove welds made with backing. Various notes apply limition groove welds in pipe to those diameters 24 inch or more, etc.
A welder qualification test consisting of a CJP groove weld that includes back gouging does not qualify the welder for welds made with backing, but it does qualify the welder for fillet welds and PJP groove welds.
I'm sure a search will turn up this same discussion a few months back. I did the search and this is my previous responses to similar questions.
"I believe there may be a misunderstanding of the term "backing" in this instance. The misunderstanding is that for production purposes (not welder qualification) backing can be a separate material, such as a backing bar or ring, it can be permanent or removable such as is the case with a copper backing bar or ceramic backing, or it can be the base metal itself as in the case of a partial joint penetration groove weld or a double sided groove weld be it complete joint penetration or partial joint penetration.
The act of back gouging a double sided groove weld removes base metal to the depth required to obtain sound metal, usually the root of the weld deposited from the first side. The metal excavated is considered to be "backing" for the weld deposited from the first side.
So, the discussion by the instructor at FabTech is not at all out of line with what has been discussed in my response. I hope I understood your consternation and that I provided some additional useful information.
Welder qualification is not the same as qualifying the welding procedure and yes, the ranges for which the welder is qualified are different than the ranges for which the WPS is qualified when the welder is qualified by the act of welding the test plate used to qualify the WPS.
As I understand it, it boils down to the following:
- Welder is qualified with a backing bar - he is qualified for fillets, PJP, and CJP grooves made with backing or back gouged and welded from the second side
- Welder is qualified with back gouging - he is qualified for fillet welds, PJP, and CJP grooves that include back gouging and welding from the second side. He is not qualified for CJP groove that require the use of a backing bar or CJP grooves without back gouging (as in pipe joints).
- Welder is qualified without backing, i.e., the test consist of a CJP groove welded from one side without back gouging (as in a pipe weld) - the welder is qualified to deposit fillet welds, PJP grooves, CJP grooves with backing, CJP grooves that are back gouged and welded from the second side, and CJP grooves deposited from one side without backing or back gouged.
- Welder is qualified with a fillet weld - he is only qualified for fillet welds.
- Job specific joint details, i.e., non-standard welder performance tests, devised by the contractor are joint and condition specific. For instance, a manufacturer that is making outside corner joints that must be ground and finished to meet specific customer driven requirements can have the welder weld up a "sample" corner joint as a workmanship sample. The welder may be required to weld a sample and grind and finish the outside corner to demonstrate the ability to meet specific customer driven acceptance requirements. That test, or workmanship sample, is for that specific joint detail and does not extend to other details.
Remember this questions was specific to D1.1 and may not apply to other welding standards. I hope this helps, but it is only my opinion and my understanding of the question."
Another response to a similar question was:
"Just thought I would stir the water and mix up the muddy bottom a little by adding my take on this issue.
The last sentence of paragraph 4.23 (AWS D1.1-2006) dealing with performance qualification says, "Note that qualification on joints with backing qualifies for production joints that are back gouged and welded from the second side."
What it does not say is that a welder qualified with back gouging (instead of backing) is qualified for production welds with backing.
Table 4.12 lists "omission of backing" as an essential variable. It doesn't say "omission of backing or back gouging".
Thinking hard and long, it is not uncommon for welders to fail the performance test because the backing is not completely fused or there is incomplete fusion along the edges of the root to the backing. Back gouging gives the welder a "second chance" to correct any unacceptable conditions in the root. It would stand to reason that a welder that passes the test using back gouging may not have the skills needed to properly fuse the backing bar in production.
The way I read paragraph 4.23 and Table 4.12 (6) is that a welder that back gouges the root of the test coupon is not qualified to weld production welds with backing.
Wouldn't this would be a great question to add to the CWI D1.1 open book examination?"
Best regards - Al
Thanks.
I wish I could say the thoughs are original, but I'm sure I'm repeating what someone before me has already stated.
Best regards - Al
I have never located anything indicating a test could be performed without backing and then backgouged. Is there a paragraph in the code that releases the restricions of the table 4.11 as referred to by para 4.19 and the requirements of para 4.23.
It appears to me that all of the tests have to be done on backing strips. Which as you indicated already, qualifies the welder for backing or welds wikth backgouging.
It seems that any test performed as a double welded joint would not be within the scope of D1.1. and therefore any backgouging and welding of the second side would not qualify the welder for anything.
If I were to observe a test with welding performed with backgouging and welding from the second side, I would have to say it is not in accordance with D1.1. (for performance)
Please refer to clause 4.18.3. The welder that qualifies the WPS is qualified by virtue of welded test plate passing the required NDT and destructive mechanical tests. One possible scenario when this might be done is when the contractor wants to qualify a joint detail that is not a prequalified joint as shown in figures 3.3 or 3.4.
The limits of the welder qualification would be governed by tables 4.10, 4.11, 4.12, and 4.13 and the associated clauses.
Best regards - Al
Thanks Al,
I was referring to the previous statement "A welder qualification test consisting of a CJP groove weld that includes back gouging does not qualify the welder for welds made with backing, but it does qualify the welder for fillet welds and PJP groove welds. " and didn't take into consideration that that statement may have meant the allowances made for procedure qualification.
I guess I should have put it in the context of a WPQ only. I do agree that the welder performing the welding on a PQR would qualify that welder within the ranges indicated for performance qualification and that test very well could be done on a double welded groove weld.
In reference to those ranges of qualification --
It seems to me there are only two conditions of backing. With and Without. The sample form for the performance qualification record only indicates two conditions. The lists of variables only indicates With and Without. If by chance I do perform a WPS qualification test on a double welded groove joint with backgouging I must decide what box to check. With or Without? Is it the same or like welding without backing? My answer is NO. Is it the same or like welding with backing ? Yes.
The statement that welding over a backing strip is harder than a backgouged joint is incorrect in my opinion. A properly fitup joint on a backing strip is much more consistant than a joint that has been gouged from the second side. The groove radius at the bottom of the joint can vary considerably as can the included angle of the joint and t he depth of the groove.
The context of paragraph 4.23 is in relationship to the performance qualification tests as indicated by the applicable figures listed below that same paragraph. All of the applicable figures require backing. Just because that statement indicates welding on a backing strip does qualifiy a welder for welding on a backgouged joint is not sufficient to indicate that a welder who welds a joint for a wps qualification with weld metal backing is NOT qualified to weld a joint that is on a backing STRIP. Again, only two conditions are listed in the variable ranges for qualification.
It appears to me that two conditions exist regarding backing . WITH and WITHOUT. Backing may be weld metal or strip. Weld metal is a type of backing, metal strips are a type of backing. They are both backing.
Now all that is left is to decide which of the above situations (With or Without) welding on a double welded groove weld with backgouging is.
If I look at many of the notes below table 4.10 welding without backing is grouped with welding without backgouging. Welding with backing is grouped with backgouged joints.
Hopefully I have not muddied the waters any. The AWS definitions of Backing seem pretty clear. I think D1.1 is too restrictive on specifying the dimenions for the tests. Maybe I want to verify a welder can both weld and backgouge. I can't do that on a single WPQ test UNLESS it is tested as a WPS. Seems kinda silly.
Any further information is appreciated and have a good day.
Gerald
There is an AWS Code Interpretation #ID1-90-024-03
QUESTION: Are welders qualified to subsection 5.19 of the AWS D1.1-90 Code also qualified to weld a full-penetration groove weld without backing, provided the root is backgouged prior to the second side?
ANSWER: Yes, within the limitations of variables.
5.19 is the description of the limited thickness welder qualification qualification coupon, (3/8" thick plate with a backing bar).
I agree and I think that was addressed above. Maybe another interpretation that could be submitted would be as follows
QUESTION: If a welder performs a WPS qualification test on a double welded groove weld that is backgouged prior to welding the second side, IS that welder qualified to weld on single welded groove welds with backing provided all other ranges of qualification are withing= the scope of the weld to be made.
My Answer : YES
Official Answer?:
Come on comittee members, the need for actually getting together to come up with these answers should be negated by the instant use of forums such as this, online meeting software such as gotomeeting or other methods. Just think of the money that could be saved on meetings and that saving passed on to the users of the publications.
I agree that the whole topic of backing can be confusing since there is not a blanket statement that indicates welding with backing or on welds backgouged and welded from the second side can be considered the "Same" as far as performance qualification goes.
And again, my answer may be wrong.
pipewelder_1999,
I am now in the rethinking mode. I was always under the same impression as you when it comes to backing.
"QUESTION: If a welder performs a WPS qualification test on a double welded groove weld that is backgouged prior to welding the second side, IS that welder qualified to weld on single welded groove welds with backing provided all other ranges of qualification are withing= the scope of the weld to be made."
My answer would be yes as well.
I ask for a official answer as well because now I am wondering about it.
And since I am the first one to admit that my interpretaions are not always spot on, we may both be in the "wrong answer boat."
Ya gotta love it!
jrw159
As you know from my previous reply, I disagree and I've given my reasons.
This is where we could argue the point until the cows come home. Only an official interpretation from the D1.1 committee would put this one to bed.
I still rest my hat on the statements I made in a previous response:
"The last sentence of paragraph 4.23 (AWS D1.1-2006) dealing with performance qualification says, "Note that qualification on joints with backing qualifies for production joints that are back gouged and welded from the second side." What it does not say is that a welder qualified with back gouging (instead of backing) is qualified for production welds with backing."
Moving on to Table 4.12, essential variables for welder qualification, item 6 lists the omission of backing (if used for qualification) as an essential variable. It does not list "omission of backing or back gouging" as an essential variable. To insert "back gouging" to that item is a leap of faith based on logic. Logic doesn't always hold with a code. You can only apply what is stated until you have a definitive interpretation from the code committee.
If you were qualifying the procedure and reference Table 4.5, item 34, the wording is different. It says, "the omission, but not inclusion, of backing or back gouging." The code committee made a conscious decision to include back gouging with backing. The same is not the case with performance qualification.
AWS D1.1 has a number of standardized tests, but D1.1 does not prohibit alternate welder qualification tests. Notice that Table 4.11 (from D1.1-2006) allows for test plate thicknesses between 3/8 and 1 inch as well as over 1 inch. The range of thicknesses qualified are a function of the thickness of the test plates. Other essential variables based on the specifics of the performance test administered is dictated by the appropriate tables, clauses, etc. I don't read anything that prohibits a contractor from administering a performance test that includes back gouging and back welding the root side.
The standardized tests included in AWS D1.1 qualify the welder to weld any of the prequalified joint details, i.e., CJP groove weld performance tests qualify the welder for any of the CJP or PJP joints included in figures 3.3 and 3.4, prequalified fillet welds, welds in skewed joints, etc. However, can the same be said for a performance test that does not use a prequalified joint detail? Is the welder limited to the groove details of the WPS that was qualified by testing (PQR)? My position would be that the essential variables of clause 4.7 (based on clause 4.21) as well as Table 4.12 would apply. Those variables include groove details, preheat, and all of those variables associated with procedure qualification. In other words, a performance test that is different from the standardized tests listed in D1.1 could place limitations on the ranges of the qualifications of the welder because of the limitation placed on the WPS that was initially qualified by testing. This is the reason why I (my personal position) insist the WPS used to qualify the welder be listed on the performance test record. It (the WPS) may limit the welder's qualifications!
The bottom line is that I do not recommend qualifying welders (working to AWS D1.1) with back gouging the root. Use a standard performance test and you will not need the bottle of "Advil" in your back pocket.
As CWI/SCWI we have to work with the written words. We simply read the words as they are written, we shouldn't be adding or inserting words where it would suit our needs. Nor can we apply the conditions of other welding standards to D1.1.
My brain is tired and I have to give these overwork brain cells a chance to recuperate.
Best regards - Al
Al,
Your standpoint is one of the driving forces of my "rethinking" of this.
Could this be a "grey area" that is in need of clarification?
John
I do agree that the below statement is contained within D1.1
"...Note that qualification on joints with backing qualifies for production joints that are back gouged and welded from the second side."...
You follow that up with " What it does not say is that a welder qualified with back gouging (instead of backing) is qualified for production welds with backing." And I agree that no such statement exists in D1.1. The fact that D1.1 specifies what the joint design for the performance qualification test shall be AND the fact that only two conditions exist for performance qualification regarding backing, it seems to me that all of the words are there that are needed.
However there are only two conditions regarding backing. With or Without. Backgouging and welding the second side of a joint must fall into one of those two conditions.
D1.1 has the following definitions
1) backing. A material or device placed against the back side of the joint, or at both sides of a weld in ESW and EGW, to support and retain molten weld metal. The material may be partially fused or remain unfused during welding and may be either metal or nonmetal.
2) backing weld. Backing in the form of a weld.
If the weldmetal that is backgouged falls into EITHER one of the two above definitions, it must be backing. That definition eliminates my need to use "Faith Based Logic".
If we make the assumpion that the code allows us to use ANY joint design we want. (I think we are restricted to the figures shown ONLY except in cases where WPS qualification Occurs) then the following situation could happen.
1) A welder takes a test on a double welded groove joint that is back gouged and welded from the 2nd side. I then have to check a box or fill in a blank on the form to record the variable referenced by table 4.12. I either select WITH backing Or Without Backing. Those are the only two options. With that established and the definitions contained in D1.1 as mentioned above, I must select the option for "WITH" backing.
2) I then come to a production joint that is a single vee groove welded from one side with backing. I have to make a decision regarding the qualification status of the welder certified by the test indicated above. All variable ranges are the same as indicated in table 4.12. The joint has backing, the welder above welded with backing. He is qualified.
You indicated in a statement above that because the code does not make a statement indicating that "....a welder qualified with back gouging (instead of backing) is qualified for production welds with backing" . Then exclusion of a statement clarifying the allowance indicates such an allowance does not exist.
Yet below that you indicate that liberty may be taken with the requirement for the type of performance qualification test to be taken since there is no statement prohibiting the use of other tests. The code clearly indicates what the tests must look like. The only exception that I am aware of is in reference to a situation in which a welder performs welding on a PQR.
If a welder takes a test as indicated by D1.1 for a groove weld with backing, that welder is qualified for ANY other groove weld that can ever be made regardless of the joint detail. The joint/WPS can be prequalified or qualified by testing. The reference to performance testing and "prequalified joint" details confuses me somewhat since prequalification of a joint has ONLY to do with a WPS.
I do think that either of us can be missing something or not understanding something in the code. Youd think with all this high technology someone could straighten us out quickly.
I agree with this statement
"As CWI/SCWI we have to work with the written words. We simply read the words as they are written, we shouldn't be adding or inserting words where it would suit our needs. Nor can we apply the conditions of other welding standards to D1.1."
The code only addresses two conditions for backing for performance qualification. With and Without. The code specifies the joint designs to be used. Because they are specified then all others cannot be used unless an exception is allowed (WPS qualification). In the case WPS qualification a welder may qualify on ANY groove needed for the WPS. This may or may not have backing. If it does have backing (Which can be weld metal, strip etc) then he is qualified for ANY joint with backing. If it does not have backing then he is qualified with or without backing. There may not be a WPS written at the time but when it is, he is qualified provided all the other variables remain within his ranges qualified.
My brain hurts too and it does seem we have different views on the subject. There may be something in my brain that is preventing me from "Seeing the light". I will look at it all agaian tomorrow.
Have a good one.
gerald
Hi Guys, I was under the impression that D1.1 committee could have been looking at this from a standpoint that the testing sufficiently demonstrates the welder's ability to place sound material in the joint so to keep it economical for the fabricator/mfg doing the testing they gave the suggested tests in Section 4. "KISS" if you will and quite possibly we are trying to read too much into what it is saying?...I dunno. But if you gave a test with back gouging rather than with a backing plate.....has the welder demonstrated his ability to place sound material in the joint any better if he used a backing bar with no chance at correcting the root..... or with back gouging the root? I agree that someone can make a mess with carbon arc gouging....but D1.1 calls out several methods of removing the root(backgouging)....ie. grinding the second side back to sound material.
I believe you see the light John; "keep it simple."
It is easy to read too much into what the code says or what it doesn't say, kind of like "how many angles can dance on the head of a pin." It also demonstrates why it can be dangerous for novices such as me to try to interpret the code. That's best left to the code committees vested with that responsibility. However, it is this type of "simple" question that gets my mind working and give me a reason to read and ponder the code more closely.
As I said in my response, it is easiest to simply use one of the prescribed tests and dispense with all of the confusion associated with a "nonstandard test".
One of the premises of D1.1 is the idea of prequalification. As long as we stick to the requirements and conditions of prequalification, the wherefores and there-fores disappear.
As for the welder that welds back gouged groove, if he complies with the requirement (clause 3.13.2) that the resulting groove resemble a prequalified U- or J-groove configuration, it should be a no brainer that he can deposit sound weld in the resulting groove. The difficulty (that I've observed) comes about when the welder doesn't keep the proper aspect ratio in mind and makes the BG too narrow and too deep to permit proper access. Then again the requirements of clause 3.13.2 are not met in those cases.
I have a hard time imagining that depositing weld metal in a proper BG groove is more difficult or equally difficult to fusing two or three separate pieces of metal together as is the case when a backing bar or backing ring is used. In this case I have to rely on my 20 year career as a "rod burner" and my twenty plus years experience as a CWI/SCWI administering welder qualification tests to conclude it is more difficult to deposit sound weld using permanent backing than to successfully fill in J- or U-groove. I will concede that each of us have different experiences and each of us have different levels of welding skills, so any welder that tells me he has a more difficult time filling in a BG has to be believed.
I wish I hadn't written that; 20 + 20 plus, it makes me realize just how old I'm getting! Hey Joe, you old fart, I'm catching up to you!
Best regards - Al
John,
You may be right about the "KISS" approach.
The simplified version of my view is
Backing
B1) D1.1 specifies that omission of backing is a variable requiring requalification for a welder.
B2) Welding a joint that is welded from one side, backgouged, and welded from the other is welding a joint with "Backing".
What Tests can be taken.
T1) The section related to performance qualification test type in Para 4..19.1 indicates that the weld types shown in specific figures are to be used. "The performance qualification tests required by this code are specifically devised tests to determine a welder's, welding operator's, or tack welder's ability to produce sound welds.
T2) Exception to what tests can be taken can be made in the case of a welder performing the welding for a WPS qualifcation. Par 4.18.1.
The Code
C1) The fact that the reference to backing strip qualifying for welding a joint is confusing because there is no option for the reverse. This may be due to the fact that it was written in the context of (T1) above in which case NO test welds are made without a backing strip/ring since none of the applicable figures show that. Or it may be written to indicate that is the only condition where one type of joint with backing qualifies for another type of joint with backing.
C2) The code refers to the various figures for weld test types in table 4.11 which would conflict with the allowance to qualifiy when performing welding for a WPS.
I am sure we have all had inspectors that were dead set on their interpretation regarding what the code said. I may be one of those but am blinded. If that is the case I hope to come to my senses soon. An interpretation from an official committe member would be nice.
Gerald
What gets discouraging about waiting for an offical interpetation is the fact that the inquiries take forever...and that isn't much comfort to an inspection in a tight spot while on the job. I fully realize that these committees are made up of volunteers that take time and resourses of their own to meet and discuss the inquiries...so it is very understandable why it takes so long....I just wish there was a quicker method of getting questions answered....maybe something like you had mentioned Gerald...a place on the AWS site to ask a question and have someone give an "official" answer in a timely manner to help those inspectors out of that tight spot while they are still on that particular job.
It is kind of ironic when you think about the fact that a person taking a CWI exam is given only two hours to answer a multitude of questions yet code committee members with experience discussing "what the code means" take much longer for just one question.
I understand the logistics of getting everyone together but again there is technology available to make that a much less difficult task. You can be pretty confident that if one message topic went up with "Free Membership and CWI renewal" as the topic heading, many would have read it in only a few minutes.
I am sure within the committe there are discussions such as this in which people do not agree and it gets worked out. That same discussion could be done online, via email etc.
I would think t hat some on the D1.1 committee have already read this but I may be wrong. If you have, what do you think about looking into a faster way to resolve interpretation issues? One advantage of this "electronic stuff" is the fact that it may be easier to get volunteers if all they need is an internet connection. I would volunteer for sure.
An online D1.1 committee could filter out questions already answered by the code and forward the ones to the actual committee that seem to have difficulty in being agreed upon.
Just a though
gerald
I have a family and committments that won't allow me to travel all over the country to participate on these committees so I fully understand where you are coming from. I have worked so much this past year that I wasn't able to make any of the Section meetings either...and they had voted me in as Chairperson. I feel very guilty for having the Section hanging looking for a replacement...but I do have a family to take care of, and I will not leave that post...sorry. Some have approached by PM and email asking, but I just don't have the luxury right now to have that much free time.
I have a question, the code states "backing", now backing comes in many forms it can be weld metal, backing BAR, base metal etc. Now if you have a groove depth that allows enough base metal to support your weld, then you backgouge to sound metal leaveing the weld as backing for the second side does this consitute "backing"?
I say yes, people tend to confuse "backing bar" with backing, thinking that this is the only means of backing. One is simple a form of the other, not the catch all.
What is the intent of this backing requirement, are we over thinking it, let's keep it simple. It is there to assure complete penetration and fusion at the joint root and to support the molten pool of weld metal.
Richard,
Here is the AWS A3.0 2001 Standard Welding Terms & Definitions for backgouging, backing, and backing bead.
I beleive this supports your standpoint.
jrw159
Topic American Welding Society Services / Technical Standards & Publications / D1.1 Backing/backgouging ...again.
