You said you were bored! It seems that I touched upon a raw nerve. I hope that isn't the case.
This thread started with the question, “is there was a separate test available for fillet welded socket joints?” My simple response was, “Yes there is.” The discussion expanded from there. I apologize if I hijacked the thread by meandering in to the realm of structural welding where large (1/4 to 5/16 inch) single pass fillet welds are common.
Try as I might, I just can't resist stirring up the mud in the puddle with a stick once in a while. This is one of those situations where I perceive a problem that isn't adequately addressed by the codes.
There are some fundamental concepts most welding standards adhere to. They subscribe to minimum workmanship requirements that have to be met to provide a certain level of assurance the welds will perform as expected. There are occasions where the codes permit alternative means of accomplishing a degree of assurance the system will function adequately. Some of the alternatives include additional NDT, in-service inspections, performance based designs, finite element analysis, etc. Even the lowly fillet weld has some basic workmanship criteria it has to meet. One fundamental workmanship requirement for welder performance testing for a fillet weld (every welding standard I’ve worked with) is that it has to have fusion to the root. Calculations depend on that fundamental principle; the theoretical throat is equal to the leg times 0.707. That is only true when we have fusion to the root. If that relationship is wrong, the throat is less than what the designer anticipated. We now have a scenario that can be a serious problem.
I believe my argument has been that large single pass fillet welds are the primary culprit. If the weld size is appropriate for the welding process and if the welder is properly trained and the necessary skills are validated by performance testing, we can all sleep better at night.
My position has been unchanged for many years. That position is that the premise that a groove weld should automatically qualify a welder for fillet welds is flawed in light of the changing technology prevalent in today’s fabrication industry. I believe many of the forum members that test welders on a regular basis and have administered a fair number of fillet break tests as well as grooved butt joints will agree with my observations.
I also recognize that those organizations involved in building pressurized systems to an ASME code do not typically administer fillet break tests to their welders. The fillet break test is more prevalent in the structural steel fabrication and erection sectors.
Trust me, I know the members of the committees, be they AWS, ASME, or any other organization, put their time, money, sweat, and tears into the valuable work they perform. It is no easy task to get a motion passed to change a code requirement. I've been involved with committee work for several years now and I know a lot of thought goes into developing the various codes and standards we use every day. I also recognize that the membership of the committees consists of people from different interest groups and there is an attempt to maintain some sense of balance so each group has representation.
I don't believe I have ever said the code committees were irresponsible. I did place the burden of responsibility squarely on the shoulders of the contractor. I did say it is something the codes should reconsider.
I trust the gentlemen that sit on any committee, ASME, AWS, or others, would not find a public debate over a code requirement offensive.
In the case of the reduction in safety factors you cite I recognize there were advances in materials as well as NDT that occurred before the reductions in the safety factors were adopted. The reduction of safety factor provides systems that are less expensive to fabricate (in the interest of the fabricator), requires more quality control and perhaps more NDT (in the interest of the boys that do such things), and in the interest of the owners (who has to look into his pocketbook to see if there is sufficient funds to make the purchase). Everyone is happy when they have to spend fewer dollars whether it is for a pair of socks, shoes, jackets, cars, pressure vessels, or a bridge.
Did I succeed in muddying the water a little? ;)
Rather than dismissing my concern and "evidence" I provided, run a couple of experiments to satisfy yourself by administering a few fillet break tests to a couple of welders and see what happens. I've had a few failed socket fitting tests where the welders tried to weld it out with a single weave bead, but the primary concern is with the large single pass fillet welds. I've seen failures with SMAW, but the problem is more severe with GMAW and FCAW using small diameter electrodes. You may experience something different than I have. I would be interested in your results. I'm not asking you or anyone to take my word for fact. I've been known to stretch the truth a wee bit. My wife still believes 3 inches is six (unless she's just playing along with my little game). ;)
Best regards – Al
Al,
I have some fellas coming in from HSB this morning so I don't have a lot of time. But let me quickly say, no raw nerve at all (unless thats what you wanted-in which case you really pizzed me off :) ). I always enjoy our debates. I suppose it may be my tone or tact. But to me its the debates that make this forum most interesting. Thus, a cure for boredom. Conversations seem to end so quickly when everyone agrees. Not to mention that the facts you use in debate are always taken seriously by me and are invaluable, and I always learn more from disagreement than when everyone happens to agree with my point of view (something to do with the great variety of experience I believe).
Trust me, when I have more time I will read your post thoroughly and with every confidence I will learn something. And perhaps if we're lucky, find something to disagree with. :)
PS: I did catch the measurement confusion comment at the end. :)
Aw yes, the old measurement trick! I am careful that I don’t use that “uncalibrated” measuring stick on the jobsite!
Like you, I always enjoy a lively exchange of ideas or experience, but your comment that my remarks regarding the code committee should be tempered caught me off guard. That's why I thought I may have touched upon a raw nerve.
No one should be surprised when I disagree with a position taken by a code or welding standard. I'm certain I'm not the only person that would like to see specific changes to the code or disagree with the positions taken by other members of this Forum on various aspects of welding. There is going to be a lively debate whenever you get two people in the same room discussing codes or any of the multitudes of issues affecting welding operations.
A good debate with you on the opposite side of the fence is always interesting and educational, but I am surprised every time you get defensive regarding code issues. I enjoy sitting in on the meetings that have anything to do with welding. The exchange of ideas and information are typically quite heated. I’m sure it's because each member of the committee considers his position to be the correct stance on the issue being discussed. Majority rules on the AWS and ASME committees and very few ballots are unanimous.
I would enjoy the opportunity to sit in on an ASME Section IX committee meeting, but it would have to be planned well in advance so I could clear my calendar. My ASME courses are planned a year in advance as are my AWS courses. In the next few weeks I will be teaching in Las Vegas, Newark, Norfolk, Orlando, and visiting Chicago (FabTech), with a few days in between to pay cloths and wash bills. I mean wash cloths and pay bills. You can see how confusing it can get. I remember a couple of years ago I decided it was time to curtail some of my travel when I checked into the wrong hotel in the right city and couldn't remember the color or make of the rental car! I'm sure you've been in the same position.
Anyway, I agree, the conversations are more interesting when there are differences in opinion being expressed. As I said, in a different thread you said you were bored! I’m delighted I was able to interrupt the boredom! ;)
By the way, if you bump into Nino O. (of HSB fame and member of Section IX), tell him I said hello. He is a good friend and member of the Executive Board of our local section of AWS.
Best regards – Al
Al,
Defensive of Code issues is not necessarily my intent. But I do believe strongly in the code philosophy of minimalism (read anti cook book) when it comes to the code, so I suppose there is an element of knee jerk.
I think an evolving code is certainly a necesity but that changes should be very carefully considered and conservative.
The basic premises of this thread are the same basic premises of virtually every proposed code revision(though motivations can vary greatly). There is a perceived deficiency in code requirements and the change proposes to remedy that deficiency.
With this I believe that it is incumbant upon the person arguing the deficiency to state their case as clear and cogently as possible.
In this case we have a clear and cogent argument that we have a problem with fillet weld tests, but not a clear and cogent argument that we have a problem with fillet/socket welds. If not, why not? The tests certainly indicate there should be. But where is it?
Add to this, the fact that the biggest problem I see is that once a rev is imposed in stone no matter how hard they try, no matter how simple the assumed change, there is always created a mountain of ambiguity and interpretation around it, and therefore greater need for more revision. This is why revs need to be carefully considered, slow to evolve, and as simple and sparing as possible.
PS:
"I remember a couple of years ago I decided it was time to curtail some of my travel when I checked into the wrong hotel in the right city and couldn't remember the color or make of the rental car! I'm sure you've been in the same position."
Not yet, but I have unconsciously wandered onto a few planes and then panicked as to whether I was on the right one or not (never mind the logic of boarding passes-machines scroo up too), only to relax when the pilot announced the destination.
However, when you check into the right hotel chain in the WRONG city then its time to curtail. :)
I spent several hours in Chicago O'Hare one night. I arrived at 11:00 PM; the connecting flight was 6:00 AM. As I strolled around to see what I could, I notice a mechanical "Robbie the Robot" attempting to pass through a metal detector. Of course all the buzzers sounded and the security people had no clue as to how to handle the robot. I followed the robot through the terminal to see what would happen next. Every time the robot would encounter somebody it would make a few comments and move on.
The robot could say anything to anybody and they would laugh. If you or I were to say with it did, we would have two black eyes. I remember it saying to two flight attendants, "Nice rack baby." They both laughed and kept walking. About that time I spotted the fellow that was operating the machine. He was standing some thirty feet away from the robot and had a mic attached to his lapel and a hand controlled in his coat pocket.
He and I talked for a bit. It seemed that he went from convention to convention with this 6 feet high robot and made a decent living with it.
The capstone was at about 5:00 AM he positioned the robot next to a gate where the passengers were disembarking from an overseas flight and started to announce in a very load voice, "Welcome to Houston, Welcome to Houston!"
The look of horror on the passenger's faces was worth the all night wait!
I still laugh every time I recount the experience!
Best regards - Al
Al,
I'm laughin now. That's hilarious!!!!
Thats just what you want to hear after a long flight. You're a 1000 miles from your destination. Or even worse, thinkin you're in Houston.
Robby would never fit in a coach seat. And I bet he could certainly silence a screamin baby.