Your opinions (or facts!) please...

Date 07-23-2009 10:35

I will do my best,

Do you require excessive undercut (on pipe in this case) to be repaired by welding or do you allow the welder to use a file to remove metal (thereby "removing" the undercut...)? Personally I'm of the weld repair persuasion, many of my peers are not. -------> IMO this can't be answered that simple, let's assume the welder repair the undercut by welding; how big is the area?, how much (or rather, how little) heat does the welder put in to the weld? how about pre/post heat, etc, etc.... I think removing it with a file can be a better solution, but again, it depends on the size and depth.

Do you allow welders to "ring" their welds with a file for appearance? If not, do you reject the weld? If you allow this, where do you draw the line between a light "ring" and a stress riser? -----> I am not sure what you mean with "ring"

Where possible, do you allow welders to reach inside pipe to repair root defects from the inside? Why or why not? -------> Most wps' I have seen or written only specify welding from 1 side, it is also my oppinion that when a welder make a repair from the inside, the heat input will be low and often done without filler material. Since your question is related to pipes I guess you mostly refer to flanges when making a repair from the inside (?) Imagine a big flange which had a few milimeters of LOP, it has been rejected on RT and has now cooled down to ambient temperature, now comes the welder and repair it with less than 1 inch of weld, what would that do to the cooling rate?

It is my own oppinion that things might be OK on lower grades of steel and without any significant requirements, but in order to maintain integrety it should be prohibited regardless of steel grade and intended service.

3.2

By aevald

Date 07-23-2009 12:56

Hello 3.2, the "ringing" that these folks are referring to is simply using the file on the toes of the cover pass welds around the entire circumference of the finished weld joint. Some welders will do this because they believe it is the proper way to complete a joint. Best regards, Allan

By 3.2 Inspector (***)

Date 07-23-2009 13:01

Aha....I have seen it, it only makes the weld/base material angle close to 90 degrees in some cases.

3.2

By pipewelder_1999 (****)

Date 07-23-2009 11:57 Edited 07-23-2009 12:00

Here are some of my opinions.

1) Removal of undercut by mechanical means is fine provided:
a) the project documents allow it. Often times a code or project specification will allow this provided tthe base metal is not reduced below a certain amount.
b) in is performed in a manner that does not just make shiny undercut (the corners of a file just make the undercut straight and shiny).

2) If a valid repair procedure has been prepared/accepted and the area to be repaired can be inspected and welded, I suggest welding from the inside. The diameter, distance from the end etc. all need to be considered. I would watch what happens during the repair and not let welders just reach inside whenever they like.

Fortunately circumferential pipe welds are not subjected to the stresses that other welds may be however that cannot change the acceptance criteria for me.

I think a file is one of the most abused tools on a pipe weld. BLEND the undercut by tapering it out and removing the notch. Random filing just because the other welders put neat wagon tracks along the toes of there weld does NOT improve the quality of a weld. I don't buy the "Taking Pride" garbage either that is often heard. I have been told by other welders that I should ALWAYs file my welds.

And though I do sometimes file, I much prefer a 20 degree re-entrant angle at the toe of the weld than filing a 90 degree corner at the toe just to impress other welders.

Again, my opinions. When in doubt, get the specs/code out.

By CWI555

Date 07-23-2009 13:26

Do you require excessive undercut (on pipe in this case) to be repaired by welding or do you allow the welder to use a file to remove metal (thereby "removing" the undercut...)? Personally I'm of the weld repair persuasion, many of my peers are not.
There is a difference in the codes and specs for this one. B31.1 will allow it, B31.3 requires it to be welded. More weld is not necessarily a good thing. The idea is to get a sound weld made in accordance with a qualified WPS with the least amount of heat input.

Do you allow welders to "ring" their welds with a file for appearance? If not, do you reject the weld? If you allow this, where do you draw the line between a light "ring" and a stress riser?
It's not up to the inspector to allow or disallow anything in this instance. The welder owns that weld until it's turned over for inspection. At time of turn over, it is judged against a written acceptance criteria. The only time this changes is for required in process inspections. The welder can make a pretty weld and then drill a hole in it for all I care. It's the final product that matters to me.

Where possible, do you allow welders to reach inside pipe to repair root defects from the inside? Why or why not?
If they have a wps and weld certs that covers it, there is no justification in making them dig it out from the face just because.

By pipewelder_1999 (****)

Date 07-23-2009 14:12

Hey Gerald,

Good post. Can you help me with the Paragraph in 31.3 that requires undercut (or any repair) to be repaired by welding. I see paragraph 328.6 that addresses repairs. But it doesn't strike me as welding being the only method for repair.

If it were accepted that thats the only way to repair, excessive reinforcement or overlap would be hard to fix if it always had to be followed up by welding but I am open for clarification. I will look at it further myself.

Gerald

By CWI555

Date 07-23-2009 14:58

I am going by a literal interpretation of the code.
328.6 Weld Repair
A weld defect to be repaired shall be removed to
sound metal. Repair welds shall be made using a welding
procedure qualified in accordance with para. 328.2.1,
recognizing that the cavity to be repaired may differ in
contour and dimensions from the original joint. Repair
welds shall be made by welders or welding operators
qualified in accordance with para. 328.2.1. Preheating
and heat treatment shall be as required for the original
welding. See also para. 341.3.3.

341.3.3 Defective Components and Workmanship.
An examined item with one or more defects (imperfections
of a type or magnitude exceeding the acceptance
criteria of this Code) shall be repaired or replaced; and
the new work shall be reexamined by the same methods,
to the same extent, and by the same acceptance criteria
as required for the original work.

I am always open to learning new things. If there is some other verbiage I am missing in the code that gives me another option, I would be more than happy to take it rather than a weld repair. paragraph 1 takes care of the issue listed in your post. The listed defects in your post are over and above the plane of a butt weld, and when you grind them to "sound metal" you need not go further. If at that time the weld is still flush or better, thats the end of it for that weld, the inspector has to accept it.

undercut is below the plane of the joint and if it's exceeding the undercut criteria in B31.3, then there is no legit way to fix it except adding weld metal to bring it back to a plane that is acceptable.
B31.1 is a different animal as are many other codes, but B31.3 when taken literally is very clear as to it's intent.

Regards,
Gerald

By pipewelder_1999 (****)

Date 07-23-2009 16:35

It may very well be the way I read it too

I too am going by a literal interpretation of the code in my eye..

328.6 Weld Repair
"A weld defect to be repaired shall be removed to
sound metal." (If the undercut is removed, is it sound metal? if excess reinforcement is removed is it sound metal? If overlap is removed is it sound metal? I take sound metal to be metal within design requirements. If NO metal can be removed, then wire brushing, removing spatter, etc could be interpreted as a "below the plane of the joint ". )

"Repair welds shall be made using a welding
procedure qualified in accordance with para. 328.2.1,
recognizing that the cavity to be repaired may differ in
contour and dimensions from the original joint.... " (I do not think this implies that welding MUST be done. ONly that if its done, this is how. I think this is where one of us is off. It very well could be me)

This one would be interesting to get an actual interpretation on .

By CWI555

Date 07-23-2009 19:24

Sometimes when posting to you it reads like I am talking to myself Gerald.

I agree on the interpretation. I'll be researching that one for any clarifications that may already be out there, and if not, I will write an inquiry to the comittee.

Regards,
Gerald

By pipewelder_1999 (****)

Date 07-23-2009 22:14

I know what you mean.

I have cspecs Turbo INT database and will take a look. It allows word, phrase and para searches.

By Shane Feder (****)

Date 07-23-2009 14:40

Gerald,
With all due respect I have to totally disagree with you on a couple of points.
The welder definitely does not (I don't know how to highlight does not) own the joint until it is handed over. It is our job as CWIs to ensure that the codes / specs are followed throughout the whole joint and not just sign off on the finished product.
I was a pipe welder for 15 years before I became a CWI and I know a hell of a lot of ways that you can attempt to fool the inspector.
And now I am one !!!
For example, pipeliners (dbigkahunna might have seen it before) used to smear mud over an area where an arc strike had been filed out. No need for MT if you couldn't even see the repair.
An inspector can only judge what he sees and if the completed weld has been camouflarged then you can only judge what you see.

IMHO there is no problem filing the edge of the cap and making it nice and straight as long as you are not digging in and lessening the wall thickness.
As for poking your head in a pipe and doing remedial repairs, I agree with 3.2.
IMHO there is nothing detrimental with doing it on basic carbon / stainless (as I did for many a year) but as soon as you start working with materials that will have their metallurgical / mechanical properties altered by doing it then it is a big no no.
How many welders would know that a 1" repair on the root of a 2" thick cold (un preheated) chromolly weld could possibly (and I stress only possibly) lead to catastrophic failure.
Cheers,
Shane

By CWI555

Date 07-23-2009 15:22

From 3.2
"Most wps' I have seen or written only specify welding from 1 side, it is also my oppinion that when a welder make a repair from the inside, the heat input will be low and often done without filler material. Since your question is related to pipes I guess you mostly refer to flanges when making a repair from the inside (?) Imagine a big flange which had a few milimeters of LOP, it has been rejected on RT and has now cooled down to ambient temperature, now comes the welder and repair it with less than 1 inch of weld, what would that do to the cooling rate?"

From myself
"If they have a wps and weld certs that covers it, there is no justification in making them dig it out from the face just because. "

From you
"As for poking your head in a pipe and doing remedial repairs, I agree with 3.2.
IMHO there is nothing detrimental with doing it on basic carbon / stainless (as I did for many a year) but as soon as you start working with materials that will have their metallurgical / mechanical properties altered by doing it then it is a big no no."

As 3.2 noted, most wps's are written from one side, they can also vary process at the root such as a tig root stick out. Autogenous welding may or may not be covered in the wps, the T of the root pass may or may not be qualified. If there is a WPS that covers it, no problems. However; as an inspector, under no circumstance am I going to make a field decision that blesses off any welder that is not already certified for a given position or other essential variable change, nor am I going to let go a weld being made without a qualified WPS. As I stated "if they have a wps and weld certs that covers it" no problems. Maybe I am unclear on what it is your trying to say, if so let me know.

As for owning the weld, we will have to agree to disagree there. If the welder is attempting to "fool the inspector" shame on him. If the inspector allows himself to be fooled, shame on him as well. The idea that smearing mud over the inspection area is going to fool an inspector has an inherent problem with it. If that inspector is trying to inspect through mud, he needs to make the RAMFO list as they don't need to be performing any inspections of welds.

The codes and specs are usually pretty damned clear on what is required for in-process inspections and final inspections. An inspector going cowboy and making up his or her own code for that, is asking for either the RAMFO or at best serious back charges by the contractor.

Therefore, the welder does in fact own the weld until they are done. If everyone has done their job right, that usually means the inspection is perfunctory.

Regards,
Gerald

By lonewolf658 (*)

Date 07-24-2009 15:42

For what its worth not beingin a class with you gentlemen.Shane is correct about the disguising of arc strikes that happens i have been told personaly if it happens to file it and then smear loose grinding dust over the area as well as smearing dirt / mud to hide it. Also this was being done at a 6g certifcation test .Instructions i have recieved which i dont agree with, if the inspector doesnt see it be quiet about it ,we'll fix it later.

By Arctic 510 (**)

Date 07-23-2009 20:58 Edited 07-23-2009 21:08

CWI 555-

For clarification, what I think you are saying here is that after the weld is done, you will evaluate it based on acceptance criteria. How do you evaluate this "ring", as undercut? There is no way to measure how much of a stress riser this is, unless you use undercut depth standards (which I am not sure is the best way to go). I can allow or disallow certain things such as this (as an owner/user inspector) by telling our welders not to do this prior to their welding. That part is easy. What I am looking for is justification to reject an obvious stress riser if it is not specifically addressed in the code (mostly 31.3 for my plant).

By js55

Date 07-23-2009 21:56

Arctic 510,
You need to be careful when considering things in terms of 'stress risers'.
Welds themsleves are stress risers.
Porosity is a stress riser.
Slag is a stress riser.
Both of these discontinuities create triaxial stress zones that decrease ductility and toughness (this is the very reason for the notch in the Charpy V notch and notched tensile testing specimens-the point of the notch is a relatively severe triaxial stress zone-even more so with CTOD's).
And both slag and porosity in most codes are acceptable.
As with undercut.
By invoking the term stress riser it is not necessarily deleterious to the weldment. Or at least deleterious to an extent unacceptable. This is the reason most codes accept certain levels of these discontinuities.
Without code, contract, or specification regarding such you have no documentative justification.

By Arctic 510 (**)

Date 07-23-2009 22:18

You're right. All of those things are stress risers. A better term might be "unnecessary" or "avoidable" stress risers.

What I gather from your post is that you are perfectly comfortable with the practice of "ringing" welds, if it is not addressed by the code, specs, etc.

In the case of 31.3 criteria for severe cyclic service (where undercutting is not permitted at all), would you consider this "ring" as undercut if it was measurable at all? It is not undercut per se, but it is effectively the same in that it is a unnecessary or avoidable stress riser, and 31.3 allows no such riser at the toe of the weld. I guess this is getting down to the letter vs. intent of the code.

By js55

Date 07-24-2009 12:33

You have to be careful when talking of 'intent' of the code.
If it is your judgemnet that this practice is the same as undercut then I see no reason to not prohibit it.
But it cannot be justified by code language or interpretation.

And unnecesary or avoidable stress risers doesn't work. Porosity is avoidable. So is slag. It is more a fitness for service assessment. Which is best left in the hands of engineers. And a great deal of research, and 100's of years of personal code committee experience has gone into the allowable levels of discontinuities. Is it right for all applications and services. Certainly not. But the codes are not cookbooks and "Sound Engineering Judgement" will always be a necessity.

By the way, I do not approve of the practice, but I still have no codified justification for its prohibition. If it is undesirable it needs to be expressed as such up front in contract, specification, or procedural documents. That is the way I handle it.

By CWI555

Date 07-24-2009 12:36

"I can allow or disallow certain things such as this (as an owner/user inspector) by telling our welders not to do this prior to their welding"

Your asking for trouble looking at it that way. As a representative of the owner, you can do a lot of things. If you start rejecting welds based on "stress riser's" that are not covered in the contractually agreed upon codes and standards, your constructor can hit you with change orders/back charges.
If I were in the constructors shoes, I'd document all those changes, get them in writing, and smile everytime I unnecessarily repaired another weld. When I recieved the check for all the back charges, I'd give a bonus out of it to all the welders.
If I were the owners QA/QC manager or project manager, I'd be adding that inspector to the permanent RAMFO list.

By Arctic 510 (**)

Date 07-24-2009 16:22 Edited 07-24-2009 16:26

It would be rather hard for our welders, who are hourly employees of my company, and not contractors, to hit us with back charges, and add me to whatever this "RAMFO" list is that you're referring to. I stand by my statement that I can disallow this practice in our welders' work.

With no fear of back charges or a "RAMFO" list (whatever that is).

:-)

I can see where this could be a problem for some situations however, and I'll keep your opinion in mind when dealing with other situations.

By CWI555

Date 07-24-2009 20:21

no one is above the ramfo list. Even if it's your company. Cost it enough money, and you will find out what the meaning is.
You are in fact costing your company money when you impose criteria that is above and beyond what is required by code or spec, if for no other reason than the added time.

By Arctic 510 (**)

Date 07-24-2009 20:38

I agree with your statement about costing one's company money. Partially why I started this thread, to get others' opinions on issues. Is ringing a detrimental enough issue to press it, and can it ever be considered undercut (especially for B31.3 cyclic service)? What I am hearing is that since the code does not address it, it is non-rejectable unless spelled out in specs.

If "ringing" is a big issue, I can ask our welders not to do it, and thereby avoiding the additional stress riser and not costing the company any money at all. I have never rejected a weld based on the application of this practice. If it is not a big issue, I can forget about it and keep on keeping on.

Thanks for your input.

By Ke1thk

Date 07-23-2009 16:21

I recently had a stainless tube root pass fail due to excessive penetration. The part was inspected to a NAVSEA Code (very high standard).

I was pressed for time. The job was late. I didn't want to weld new samples and pay to test them, again.

I asked the Level III inspector at the Lab if I could grind out the high spots. We pulled the code and researched. His evaluation was, "Yes, if and only if the repair is part of the procedure and accessible to the end of the tube with the grinder."

I was suprised that it was acceptable.

Good Luck,

Keith

By js55

Date 07-23-2009 18:18

For the great majority of materials and applications there is nothing inherently problematic with ID repairs of welds, either metallurgically or mechanically as long as, as Gerald made clear, you have the proper quals in place.

By 3.2 Inspector (***)

Date 07-23-2009 18:51

well, I guess that is stating the obvious....
The weld does not know if it was made from 1 or 2 sides.

There is little limit in what you can do, as long as it's tested, approved and qualified.

3.2

By scrappywelds (***)

Date 07-23-2009 21:01 Edited 07-23-2009 21:05

on the "ringing" of a weld, my company does allow it. THOUGH THE TERM "RINGING" HAS BEEN DEFINE FOR US "STUPID WELDERS", RINGING IS USING THE EDGE OF A FILE LIKE A HALF ROUND TO STRAIGHTEN OR PRIMARILY REMOVE UNDERCUT. THEY DO ALLOW THE FLAT OF A FILE TO BE USED TO STRAIGHTEN THE TOES OF THE WELD AND TO REMOVE SPLATTER. THE REASON WHY I HAVE BEEN TOLD WE CANNOT REMOVE UNDERCUT WITH A FILE OR GRINDER IS THE MIN. WALL THICKNESS HAS BEEN DECREASED AT THE AREA OF "REPAIR".

By Arctic 510 (**)

Date 07-23-2009 21:25

I got the term "ringing" from a "stupid" welder, when I was a "stupid" welder. Now I am an inspector, but the "stupid" part followed me. :-)

(Usually the welders have less endearing terms to use - Point of advice here - when you're cussing out the inspector, make sure he's not standing on the level of scaffolding just above you. One of our welders was telling his helper how sick he was of waiting on the "-------" inspector -me-, and there I was-unknown to him, looking at his weld! I got a laugh out of it but boy was he embarassed!)

As a prior welder, I have nothing but the utmost respect for welders.

By Shane Feder (****)

Date 07-24-2009 00:25 Edited 07-24-2009 00:28

Gerald,
Please forgive me if I am wrong but it appears to me that you are advocating something along these lines - get that car from point A to point B, I don't care how you get it there but as long as the car arrives undamaged I am happy.

"Therefore, the welder does in fact own the weld until they are done. If everyone has done their job right, that usually means the inspection is perfunctory."

If "everyone has done their job right" most of us here on the forum would be out of a job. There would be no need for welding supervisors or welding inspectors.
A final inspection is just that, it may be visual or it may be volumetric but there are a multitude of things that can be done wrong (or not in compliance with the code) during the welding process that will not be picked up by the final inspection.
That is why in process inspections are so critical.
If I walk out my office door now and see a welder welding vertical down when he is only qualified for vertical up I will say stop - cut that weld out.
Who owns the weld now ?
If I walk out my office door now and see a welder welding a s/s butt with 7018 I will say stop - cut that weld out.
Who owns the weld now ?
If I walk out my office door now and see a welder welding straight over slag without cleaning first I will say stop - cut that weld out.
Who owns the weld now ?
The list goes on and on.

ASME IX allows the supervisor to stop the test at any time when he feels the welder does not have the required skill. Who owns that weld ?, definitely not the welder.

The crazy thing about this arguement is that I used the analogy of a welder "owning" the weld in a recent post. I just didn't mean it in this way.
http://www.aws.org/cgi-bin/mwf/topic_show.pl?pid=143001;hl=ownership
Regards,
Shane

By lonewolf658 (*)

Date 07-24-2009 15:49

Please enlighten me tot his .I was under the impression at any given time a inspector could walk up watch as a weld is being made and if it wasnt by the standards could stop the process,if i am mistaken in this please correct me! I dont know much but what i do know i try to remember and yes i will listen to everything you guys say lol (i know i asked for it)

By 803056

Date 07-24-2009 16:12

You fine gentlemen have covered most of the bases, so I'll simply be adding my opinion to what has been said.

Filing the surface of the base metal adjacent to the toe of the weld is fine if it simply removes spatter and minor imperfections that do not reduce the pipe wall thickness below what would be acceptable for undercut. Filing that changes the reentrant angle of the weld toe in a manner that causes it to be reduced to near ninety degrees is not desirable, but is a real concern if cyclic loading is involved. Blending undercut to reduce the notch affect is fine as long as it doesn't reduce the wall thickness more that that permitted for any undercut. It would be acceptable if left unattended and it is no worse after being blended (again the proviso is that the wall thickness is not reduced by the "blending" action).

I have seen the filing of the welds carried to the extreme and to the point of being ridiculous, but it was considered standard practice. The practice I am thinking of seemed to be limited to powerhouses. The toes of the weld were filed to form a perfect ninety degree corner and the face of the weld filed flat. The resulting weld reinforcement would vary depending on the thickness of the pipe wall, but would average about 3/32 inch and it would form a perfect rectangular cross section sitting atop the weld. The more perfect the ninety degree corners, the better.

I asked about this practice at one nuclear facility where I was teaching and they responded that it was standard practice at their facility. I asked if they found many cracks and they responded in the positive. I asked if they usually occurred at the sharp corner of the weld toe and again they responded in the positive. I asked them if they though there was a correlation between the sharp reentrant angle at the corner of the weld toe and the cracks they were finding. Their response was that without the sharp corner they wouldn't know where to look for the cracks.

Then I asked the big question, If they were to grind the weld flush, do they think that perhaps the frequency of cracking would be reduced significantly? Their response was then we wouldn't have any one place to look for cracks, we would have to examine everything.

Best regards - Al

By CWI555

Date 07-24-2009 20:30

Shane, we will have to agree to disagree on this it seems.

The codes and specs are usually specific on what level of in process inspection that is to be performed.
Most codes above AWWA require a specific level of in process inspection. At any one of those stages it is the inspectors job to bust something within the bounds of the acceptance criteria and code.
However; Should the welder bust out on an in process, I will not count that weld against their stats. If they bust out on a final, that does count against them.
The welder therefore owns it until it's final. After they declare being done, it belongs to me.

That is how I see it.

Regards,
Gerald

By Arctic 510 (**)

Date 07-24-2009 16:25

I appreciate all of the input and opinions so far!. Thanks to all!

By swsweld (****)

Date 07-26-2009 22:19

Last year I walked in a mechanical room still under construction and as usual looked at the pipe welds overhead and saw something I have never seen before. I thought the toes were filed (ringed) also have heard it called wagon tracks, but when I got a ladder to get a closer look, the welds had a band saw ring around them. No file was used, a portable band saw. I got a flash light and determined the cuts were approx. 1/16" deep. Confused as to why this was done on every weld by a certain stamp on it I wondered if they were going to cut his welds out. So I found the mechanical contractor superintendent and asked him what the deal is and he was not aware of the situation. I explained the problem with this and he said he would look into it. I described the scenario of several welds failing a week before their warranty expiation and having to remobilize and repair the welds in a finished environment instead on fixing it now.

Just a renegade welder doing things his way to make the welds even.

I was just another contractor on the job, not inspector or QC. I knew the supt and knew that he would deal with the situation as he seemed to do good work on that project.

By Arctic 510 (**)

Date 07-27-2009 17:08

A bandsaw? Wow! I've never seen that one, but I've seen it done with a thin grinder disk!

By swsweld (****)

Date 07-28-2009 03:02

Yea, WOW.
I forgot to mention that the Mech. Supt investigated and confirmed that the "welder" ringed it w/a band saw. Bazaar.
I've been it the trade since 1978 and that was a first for me.