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Up Topic Welding Industry / Inspection & Qualification / B31.3 Interpretation Request
- - By Arctic 510 (**) Date 10-05-2009 19:32
All-

Previously a discussion was had over the practice of welders "ringing" their welds with files, grinders, even bandsaws in an effort to make them "look better" and perhaps hide/remove undercutting.  My concern is with extreme instances of this, especially in cyclic service, creating a notch at the toe of a weld.

I wrote to the B31.3 committee for an interpretation concerning this (#09-1444).  According to their response, this issue is not currently addressed in the code, but is now an agenda item for further discussion and consideration. 

Thought I'd let those of you who may remember and/or be interested know.
Parent - - By paul prill (*) Date 10-06-2009 15:56
The way i see it undercut is undercut no matter if its done with a electrode, file, grinder, hacksaw or porta band.
Parent - - By Superflux (****) Date 10-06-2009 16:54
Undercut is from improper welding technique.

UNDERFILL is insufficient weld metal deposit(ed).
Remember Part B!

If undercut is removed (blended) beyond tolerances, then it is Underfill and an incomplete weld. Peroid!
Parent - - By Arctic 510 (**) Date 10-06-2009 20:31
I agree on your definition of underfill, and obviously undercut is from improper technique.  The effect ringing of welds often has on a finished pipe fabrication is twofold, and I don't believe either neccessarily qualifies as underfill.  Ringing most often results in a sharp angle of transition between the weld and parent metal, and digging a groove into the parent metal adjacent to the weld toe.  This creates an undesireable notch, not underfill as you say.  It doesn't truly create undercut either, by definition, only an undercut-like effect.  I do remember Part B.  :-)

Blend grinding or filing is allowable, according to the committee's answer to question two in my request for interpretation, as long as Table 341.3.2  requirements are met, as well as pressure thickness requirements in para. 304.
Parent - - By eekpod (****) Date 10-07-2009 10:43
Not working in the piping industry, this "ringing" you are talking about. 
They are basically removing by file or grinder some base metal to blend in the transition of the U/C or lack of fill that they had originally to the base metal?  That's why they do this?
This is new to me.  Even though it may not meet the definition, it sounds like before they "ringed" it, there was a condition that warranted repair/ re-work, and the solution was to "ring" it, but it removes base metal creating a notch, and thus an unacceptable repair method.
How about looking at this from the perspective of base metal thickness, could they have removed a certain percentage via "ringing" that would require it to be reinstalled? 
I would agree with the definitions as posted earlier about U/C and lack of fill, that's right on the mark.
Chris
Parent - By js55 (*****) Date 10-07-2009 13:14
The danger of ringing depends upon just how deep the ringing is. If all you are doing is removing the oxidation to make the weld toe shiney it is harmless (I believe the depth of oxidation is still well within the AWS cyclic service restriction on undercut). I would however say that the very restrictive AWS cyclic service limitations for undercut should be considered though they don't really apply.
As a rule of thumb I would argue that if a depth of undercut is acceptable then a depth of ringing is acceptable.
Don't get me wrong, I do not advocate the practice, mostly on production grounds,  but we can get too carried away with consideration of it in most instances and there is no code restriction that I know of to directly justify rejection.
Parent - - By CWI555 (*****) Date 10-07-2009 19:44 Edited 10-07-2009 19:48
Note the ringed area no longer has a sharp transition. If your min wall is not violated, and your transition does not leave a notch after ringing, tell me what the problem is? Underfill is typically a larger problem do to much larger amount of weld material that is missing.
Parent - - By Joey (***) Date 10-08-2009 03:47
Just want to share what I read in the Inspector's Handbook supplied by our trainor from US during API 570 course.
Attachment: RingingaWeld.doc (256k)
Parent - - By Superflux (****) Date 10-08-2009 03:56
Typically, the "ringing of welds" I encounter ARE in violation of minimum wall thicknes and transition values. Therefore, I use the Underfill as a diplomatic and documentable basis for rejection.I can show any one this in the book and with my Cambridge gage.
Parent - - By Shane Feder (****) Date 10-08-2009 05:32
Hello guys,
Have to agree with Gerald and Jeff.
It is outside the weld zone so it cannot be considered underfill.
Ringing is used every day all over the world and as long as the depth is not excessive I do not see the problem.
There is a major difference in "ringing" a weld where the welder is attempting to remove / disguise undercut and "ringing" a weld where the welder is filing the weld metal to make the outer edge of his cap / reinforcement perfectly straight. As long as the file is kept flat on the pipe and the edge is in contact predominantly with the weld metal there is very little parent metal removed. Definitely not enough to make the weld rejectable.
Regards,
Shane
Parent - By eekpod (****) Date 10-08-2009 10:18 Edited 10-08-2009 10:22
Now don't forget, the original post specifically states in his situation he has an extreme amount of "ringing" on a cyclically loaded pipe.
Again, I'm not familier enough to help, but I am following this just for professional education on my part.
It still seems like the welders are trying to disguise the original u/c or lack of fill by extreme amounts of "ringing" the weld weld to mask the original situation.
That attachment is interesting; it clearly points out "ringing" is a problem when done incorrectly by creating a notch, but then goes on to say there is no code violation in doing so, even though it creates a stress riser that may be detrimental to the part,,, that sucks.
Parent - - By bert lee (**) Date 10-08-2009 11:49
will the ringed area corrode first than the weld?
for those existing pipeline, i noticed that part is the most rusted when paint peel off

could be due to surface condition before painting,

bert
Parent - By Richman (**) Date 10-08-2009 13:59
Probably you can find the answer to your questions in B31.3 piping welds acceptance criteria.
Parent - - By js55 (*****) Date 10-08-2009 14:07
Before we get too carried away with the stress riser idea lets keep in mind that a weld itself is a stress riser.
So in a sense, we can use the technical language to make an argument here but the bottom line is, is there evidence we have a real problem here or just an assumed problem based upon an idea of good or bad practice?
I can talk ad nauseum about reduction of cross sectional area by porosity, and slag, and how from a technical standpoint it should be eliminated from weldments because of its possible detriment to optimum performance. But is total elimination of porosity and slag necessary? If I argue to accept some porosity and slag or undercut and ringing in the weldment am I risking disaster or advocating bad practice? Why? Why not? Becasue the code says some porosity is OK and yet doesn't address ringing?
Food for thought maybe.
Parent - - By ssbn727 (*****) Date 10-08-2009 15:17
Aww Jeff!
You're just itching for a debate!!!

Things must be really boring at work these days!!! :) :) :)

Respectfully,
Henry
Parent - - By js55 (*****) Date 10-08-2009 16:25
Henry,
LMAO!!!!!
Nah. Its hit and run.
Parent - - By 803056 (*****) Date 10-12-2009 17:51
As is often the case, a little of something may be fine, but carried to the extreme may prove to be harmful.

I've seen cases where the welder ran the file around the pipe to clean up spatter and blend minor undercut (whatever minor undercut is) and the "ringing" of the weld was not to the point of being obnoxious.

I've also seen the case where the helper took great pains to file the toe of the weld to a perfect 90 degree angle and the top of the weld was exactly 1/16 inch higher than the adjacent base metal and perfectly flat.

I've mentioned this in several courses I've taught. I talked about "flat topping" at one nuclear station and one of the inspectors told me it was required practice at their facility. I asked him if they typically found PT or MT indications of cracks at the toes of welds that were finished in accordance with their practice.

His reply was, "Hell yes." There was a murmur of general agreement amongst the inspectors and welder present.

I asked him if it was reasonable to expect the welds to perform better without the stress riser introduced by the practice of filing the toe of the weld to a perfect 90 degree corner. His response was, "Then we wouldn't know where to look for the cracks."

Seems perfectly logical to me!

Best regards - Al
Parent - By ssbn727 (*****) Date 10-13-2009 01:09
ROTFLMFAO!!!:) :) :) How tidy they be as they attempt to adhere to the NRC!!! ;) ;) ;)

Respectfully,
Henry
Up Topic Welding Industry / Inspection & Qualification / B31.3 Interpretation Request

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