I would also suggest getting yourself a film interp cert. Your basically unarmed in a situation like that. I have not looked up the particulars as to the size, but pores do in fact come with tails from time to time. Then you get into "interpretation", and thats where training and experience comes in, which is subjective to a large extent based on that same experience and training. I've worked as a TPI for a number of years up until 3 months ago, you get into issues with a lot of companies claiming to be "TPI", but in reality, they are NDT or similar company, and not a true TPI in my opinion. If whatever your having that "TPI" work on fails and cost lives or reams of money, thats when you find out the difference between an IACS company or SME and an NDE company.
IACS companies
ABS American Bureau of Shipping
BV Bureau Veritas
CCS China Classification Society
DNV Det Norske Veritas
GL Germanischer Lloyd
KR Korean Register of Shipping
LR Lloyd's Register
NK Nippon Kaiji Kyokai (ClassNK)
RINA Registro Italiano Navale
RS Russian Maritime Register of Shipping
BV, GL, LR, and DNV in particular keep on staff personnel who will carry more weight than billy bobs NDT company TPI.
To carry any weight outside of those organizations, you've got to have recognized industry SME's such as Joe cane, Al, and people like that, otherwise your just wasting your companies money.
I say all this as by the guys reaction of running it up the flag pole to the level III, he showed some uncertainty. Had that been my call, I'd checked it twice before opening my mouth, then when I did, I would stick to it hell or highwater. The last thing you need come court time is uncertainty being displayed in any form.
swsweld,
Agree totally with CWI555.
Although ASME VIII Div 1 Appendix 4 Rounded Indications is not the code you are working to but it does explain the terminology ASME uses.
4.2 Terminology (a) Rounded Indications..........These indications may be circular,elliptical, conical, or irregular in shape and may have tails. When evaluating the size of an indication, the tail shall be included.
If the maximum rounded indication allowed was 0.083" and you had a rounded indication that measured 0.100" including the tail then it was a definite reject.
One would have thought that an RT II would have been able to show you this information (or advise you where to find it) to avoid any confusion.
Regards,
Shane
Thanks Gerald and Shane.
I'm still curious as to why 31.1 doesn't have the porosity acceptance standards for RT but refers you to Sect. I Appendix A-250?
Or have I overlooked it?
The Level II is actually the office manager that is qualified to perform and interpret the RT but normally works in the office. He was filling in for a guy that was on vacation.
I agree that interpretation is subjective and based on training and experience.
I would have called the irregular indication an inclusion but can't rule out that it was porosity.
Most of my film reading experience has been as a welder or supervisor and fortunately haven't had to view TOO many :)
swsweld,
it makes a diference what the thickness of the material is. 1/4 inch to 2' inch thick the Relevant Indications have to be 1/32nd or larger. Rejectable has to be 1/3t for isolated and 1/4t for random. I would kick this up to their Level III for review. At a min. I would spell out that the company your using bring with them on the truck,
1. relevant codes
2. the film class you want, D4, D7 ?
3. densitometer that is calabrated and has paperwork to back it up.
4. Certs of the level II tech your using that is reading the film and puting his/her name on the reader sheet.
5. The companies Radiography procedure.
6. UT D-meter
If they want the work they will comply.
Thanks
Jim
Jim,
There should be no need for review.
swsweld has stated that it is 3" Sch 40 which is less than 1/4" wall thickness.
That gives a maximum acceptable dimension of 0.083".
swsweld has also stated that when he looked at the film it appeared the defect was "greater" than 0.100".
Seems pretty clear cut to me, as CWI555 stated the Level II should have rejected it and stuck to his guns (having the applicable code with him would have helped)
Regards,
Shane
Does it matter that a backing ring was used? Seems irrelevant to me as far as thickness goes. Afterwards he said it could have been burn through instead of porosity. Sometimes on the smaller diameter pipes you may start to burn through leaving a small "divot" in the backing ring. If you can read the puddle and stop in time you can prevent a full burn through. I didn't make the weld but I made the repair and did not find porosity or slag. I found a small void that would be consistent with a partial burn through because when I found it I was at the ID immediately. The regular RT guy had previous experience with backing rings but this guy did not.
Admititly, I know that it is not always easy to make the right call every time. If slag, that was acceptable. Burn through acceptable? Porosity without a tail acceptable. Porosity with a tail rejectable. Lesson learned, priceless.
I actually said that if you look at it long enough you might see a tail :)
Sorry Shane,
I missed the part about where swsweld said he had already made the repair. I still would have kicked this up to his level III. As swsweld mentioned he was unsure about the tail. He also thought the defect was smaller than 0.083. This is one of my pet peeves. Weld repairs can be very expensive to do. You can get alot of milage out of kicking a read back to the Level III. It keeps the Level II guy on his toes.
Thanks
Jim
Jim.
No need to apologise.
I am a CWI and former RT II and I get extremely disappointed when contractors query calls when they don't have the training, experience and qualifications to be able to make the interpretations.
I realise repairs are expensive and nobody likes them but if you are not happy with the service provided by the NDT company then find another. If you are confident of the competence of the person viewing the films then you just have to live with the decision no matter how much it hurts.
swsweld has admitted that his RT interpretation experience is limited,I personally have never seen a slag inclusion with a tail and yet I have viewed hundreds of gas pores with tails (we call them wormholes in the Southern Hemisphere.)
Not having seen the graph it is impossible to say whether the call made by the RT II was correct or not.
Hope this does not sound like a rant, I haven't had my morning coffee.
Have a great day,
Shane
There is a great radiographic reference book made by DuPont. It shows you radiographs they made and cut apart.
From my experience the little "tail" indicates a lack of sidewall fusion. RT has a hard time recording this defect. The little "tails" give it away.
Get that book if you can. It shows a radiograph and a drawing of the cutaway of the weld where the defect is. I gave mine to a helper in the hopes that he used it wisely as it was passed onto me. I wished I had it back though as it is a wonderful tool.
Orientation is everything in the case you've described. I've had the good fortune of working government contracts where those kind of things are investigated to the nth degree. There is a specific appearance to what you describe. between the density shift from tail to pore, the inherent orientation, and part configuration it may or may not be an associated LOF.
I have the dupont book btw, as well as kodaks, agfas, and a few others. They are excellent resources as you've described, but they cannot display every possible scenerio or you wouldn't be able to pick the thing up.
One such scenerio that is relevant is what happens on a tank wall RT or any member in high compression. On film it will look like a tail porosity when in reality, it was a star crack. Since RT requires a cross section of some level of a void for an image formation, when for instance there are 3 courses of thick plate on top of it in an LNG tank with high nickle weld. It will look like a small pore with a tail. upon excavation, and PT of the flaw, (assuming sensitivity of 2 or better) you will see fine crack lines.
Then there are interbead pores with tails. The omnibust term lack of fusion could apply as there is no fusion in the area of the tail or pore, but then again, any void could be considered LOF by that train of thought. However; it is my opinion that the presents of the porosity qualifies the nature of the tail if it is connected.
Overall, the material, process, geometric configuration, and a host of other factors determine what the image actually is.
No one set rule covers it all.
Respectfully,
Gerald
Good morning Gerald,
What is the name of the Dupont book (maybe order number) you are referring to? I would like to get one.
Thanks
Jim
It's in storage at the moment, I'll get it out and get you the info.
Gerald,
don't put yourself out. Whenever it's fits your schedule is fine.
Thanks for your help.
Jim
Sorry to have "extremely disappointed" you Shane. I have been involved in RT work since 1979. Mostly nuclear and fossil fuel plants. As part owner (contractor) and CWI I see nothing wrong with questioning a borderline call. I stated that I respected his credentials and made the repair. I stated that this guy was filling in for the regular guy that was on vacation and that he (although qualified) was probably rusty. He's the office manager. Interpretation is not an exact science. Mistakes can be made. I didn't agree that the indication had a tail. The round indication was acceptable. I have been on the bad end of some unethical situations and wrong decisions by NDE personel. I have great respect for the vast majority of people in that profession. The following sentences are not meant to critisize the industry just some cases I have encountered.I had a level II tell me that my weld was acceptable by code but he was going to reject it because the AI was going to be on site in a couple of days. A couple of years ago a different RT company rejected one of our welds late in the day when he knew at lunch time just so they could make another day on my nickel. They did not get this current contract because of that bad decision. This was our first reject on this job and if there are too many rejects our % requirement will go up from 10% to 25%. That doesn't mean that the RT tech had that in mind but as the company CWI, owner and sometimes repairman I have to look out for the best interest of our company.The RT tech later said that he could have called it burnthrough and accepted it.He watched me repair it and it wasn't porosity with a tail it appeared to be a backing ring that had a "divot", a near burn through. I don't have a RT interpretation cert so I downplay my experience so that I don't come across as arrogant(I certainly have a lot to learn henceforth the thread ) but have been involved in NDE off and on for 30 years as a welder. That does count for something. Inclusions can be irregular, so can porosity with a tail. When we parted I told him no hard feelings for the disagreement and said that if anything this will help the welder that made the weld that was rejected to be more contiencious.You may have had some very unpleasant experiences to give you the attitude that contractors have no right to question the call of NDE's but try to see both sides of the story. The reason that I didn't let him take it to the level III was financial. If I repair it now they reshoot it, if good, we're done. If the level III rejects it they comeback and bill me for another day and the level III's time.Not trying to pick a fight Shane I appreciate your post as well as the others. Going to Starbucks now. Good day mate :)
"That doesn't mean that the RT tech had that in mind but as the company CWI, owner and sometimes repairman I have to look out for the best interest of our company. (*A)The RT tech later said that he could have called it burnthrough and accepted it."
"He watched me repair it and it wasn't porosity with a tail it appeared to be a backing ring that had a "divot", a near burn through"
*B) " I told him no hard feelings for the disagreement and said that if anything this will help the welder that made the weld that was rejected to be more contiencious"
I am a level III, and had this guy worked for me and made the statement *A he would be gone.
That may sound harsh, but if he knew what it was to begin with as that statement implied, then rejected for some BS he knew not to be true, his integrity has just went out the window. At the end of the day, your integrity is only for sale once. Once sold it's forever sold in my opinion. This is especially true for a company selling themselves as TPI. (refer to my earlier post)
comment *B puts your company at risk in light of what happened with comment *A. There is more to this than just walking away and letting by gones be by gones. Should this incidence come to light in the face of a failure, the wrong people are going to want to know why this was let go without reprecussions, and why you and your company continued service thereafter. In that scenerio, your going to find your feet awfully close to the fire.
I'll back any level II that works for me to the nth degree. If they simply screwed up due to running across something they are unfamiliar with, or had some other mitgating factor such as fatigue etc or even a momentary brain fart, I'll help them out to the best of my ability. However; if they deliberately, and knowingly did something like that, I would burn them at the figurative stake. At root, lack of integrity has killed many a people, cost companies from 1 to billions of dollars and uncountless time and agrevation.
My thoughts on it for what it's worth.
Gerald
swsweld,
I did not mean it as a personal attack, and I apologise if it appeared that way.
However, you stated yourself that you hadn't viewed TOO many graphs whereas in 4 years as an RT II I would have viewed thousands.
Every now and then you will call a repair and find out it is something different upon excavation, that is unfortunately unavoidable. You can only report what you see on the film based on past experience/knowledge and if you think it is a gas pore with a tail and it exceeds acceptable size then you must call it as a repair.
If you are a CWI and I am a contractor and I disagreed with your call on a visual inspection but I had no qualifications would you not be "disappointed". It is exactly the same with an RT interpreter.
Regards,
Shane
No worries Shane. You make a valid point in your last sentence. I can see both sides of this situation. If I were to reject a weld and the contractor or welder were to disagree respectfully and had legitimate issues I wouldn't get upset. If he was a jerk and an idiot I would get very upset. (I even learn things from our helpers from time to time.) A lot depends on his competence.
My first issue was that the indication on the film was much smaller than his chart.
When I inquired about that he said the chart was a copy of a copy of a copy... I asked did they enlarge it 110%. That's when he mentioned a tail. After disagreeing with the tail and not having the code with him (15th trip to the site)I asked him to go lay it out and I will repair it. I did not dispute the other defect. Just fixed it.
I've been in the room when the golden arm welder throws the fit and SWEARS that it is not IF. It must be the counter bore transition. We later gouged out 49" of a possible 75" of IF on a 2G down comer.
On the flip side we (a previous specialty machine welding company) were punished by UT's when we passed almost all RT's. I know that is very possible. The company doing the NDE had a construction division that didn't get the contract. They did get the NDE. We were foreigners taking their work. Seems like a conflict of interest. We flew our level III over to stop the bleeding.
On our jobs I show great respect to all NDE that I cross paths with. I know how difficult the CWI cert was and to all the people that have achieved other certs have my respect. All PT and VT indications I fix without a word even if I don't agree. I have learned to pick my battles. If I feel the evidence is on my side I will respectfully disagree.
I know that it is a very difficult job and often an unpopular one and as you said an occasional bad call is unavoidable.
My philosophy is to give the NDE guys nothing to reject. Unfortunately that too is very difficult.
I apologise if my previous response was a bit harsh.
Tim,
No worries, I probably didn't word my original response very well.
Regards,
Shane
By tomas
Date 07-14-2008 22:13
Hey there!
If she looked anything like a teardrop then she was probably elongated porosity.
I dont have the spec in front of me now but the numbers sound about right. I'm interested in knowing the width (perpendicular from head to tail of the indication). If length is three times longer than width then flaw is usually deemed linear and rejectable anyway. Just a thought.
