js55
Fighting words! What I have not said in the previous reply was that I know through experience that the fabricators are not re-melting the "Tack Weld / continuous tack weld", but do not have the explicit authority under the Code to require them to demonstrate.
As for looking for reasons to disallow the "full length tack weld" without preheat, I feel quite justified in saying that "Full length" tack welds are not what the average person envisions when they think of tack welds. When I heard they were doing it, the alarms went off in my head, and I researched the Code provisions for justification. proper research revealed that the code was neutral on the subject.
I then tried to get the EOR to require them to demonstrate that they could fully remelt the Tack Welds made per D 1.1 Para. 5.18.2.2 without preheat. Again there is no specific authority in D1.1 to allow the EOR to "Require" it.to be performed. So, I have good reason to doubt they can conform to Para 5.18.2.2, and fully re-melt the tack weld with the first SAW pas, but I cannot prove it without their willing cooperation. (Destructively tested mock up weld would be required.)
As a third party inspector, I often try to disallow something that I don't like. Of course, I don't do it without "Chapter and Verse" justification. for instance, on this project one of the subcontractors routinely preheated to 800 degrees so he could make multiple passes without re-heating for the next pass. This is proscribed in D 1.5, and in ASME, but after research, I found out it was not addressed in D 1.1. Also, in my investigation I found out that the D 1.1 Committee had rejected this limitation before! The EOR did not want to allow this, to be done, but he had already approved the WPSs where the maximum preheat temperature was not addressed. So, now when the contractor would not cooperate voluntarily the EOR was out of luck. However, when the contractor submitted a new higher deposition WPS, the EOR would not approve it unless they agreed to a 450 degree maximum preheat limitation. Now the contractor was out of luck!
You see, the contractor is a low bidder, and if the EOR imposes something new on them, they get to back charge and feel justified in recovering not only the difference in price due to the change, but the diffference from profit they are actually making and how much profit they wanted to make on the job.
I think of my actions as being "Responsible". I am in fact a replacement to the previous inspector who was removed by the owner for other weld conditions that came out in the first set of columns. It is always the inspector who gets asked "Why did YOU let this happen?". (Of course you didn't make weld one on the whole project, and their QC let it go, or didn't even inspect at all!) To me, it is not just CYA, but responsibility to the public safety. So, as long as I don't impose something on the contractor that is not required by code or contract specifications, I feel completely justified doing due dilligence research. If I don't, I will be that "Last F___ing Inspector"!
Furthermore, as a third party inspector, I find that the contractors are always trying to get one over. I am always dealing with EORs who will allow something improper to be done without supporting the NCR written by his inspector. In this case above, the EOR doesnt know anything about welding, so he has deferred the welding issues approvals / disapprovals to the Port Authority Engineers.
I am the Eyes orf the EOR, and It is my responsibility to make him fully aware of all conditions and the reasons for my comments.
Joe,
You are absoutely right in stating that contractors sometimes try to get one over. And inspectors are there to see that they don't, within their authority, within the contract, and within the code. But as soon as you step beyond contract and code requirements and attempt to impose your own will you are no longer an inspector. You are a self appointed engineer.
As for full length tacks I'm wondering how it is the Engineer could find no justification within the bounds of the posted definition to halt a process wherein it was clearly way way beyond 'holding parts in proper alignment'.
The engineer certainly has the authority to impose such a clear and intended interpretation. It seems as though he was just reluctant to do so. IMO your answer wasn't to be found in 5.18.2.2 but in AWS 3.0.
And far from fighting words, in the case of full length tacks we would be in total agreement. And it seems to me under AWS 3.0 the full length tacks would be justifiably disallowable. I'd put the hammer down on that myself.
I've seen some absolutely atrocious pipe ends due to thickness variations, out of roundness, etc., used Deerman's, dogs, port-a-powers, spiders, etc., and never seen a situation where a tack needed to be the full circumference to hold alignment.
js55
The reality is that the fabricator really does need full length tack welds to hold this assembly together during the preheat cycles until they can get two or three SAW Filler passes welded. I have often seen very substantial tack welds crack simply from the preheating operation. Many times the tack welds cracked as often as three times! These are really massive steel columns made of GR. 65 material and the welds are highly restrained. Preheating of just two of these columns and maintaining it for five days of 24/7 welding used 750 gallons of propylene and cost the contractor $4000.00.
One of the contractors also needs a full length tack weld to provide a backing so that the root gap does not allow the SAW Flux to drip away. Yes there is a 1/16 inch gap limitation by Figure 3.3 (TC-P4s joint), but in some areas it may be a little larger due to the thickness of the metal and the ASTM dimensional allowance limitations. The fabricator made this pitch to the EOR, and the EOR bought off on it. The EOR did not know, (or did not connect the dots,) that there was no preheat, but now, legally, cannot go back on his approvals without incurring back charges.
At one of the fabricators, tack weld cracking was a problem even when the assembly was preheated for tack welding. They also tried lower preheats, to no avail.
As for the legal ramifications of imposing changes, The owner's legal branch has a lot of case law experience with back charges and knows how the courts will rule. I have consulted for clients that have back charged this owner for things you and I would think are "Understood", such as visual inspection, and win! Thus, when they direct me not to enforce some aspect of the Code, or let something go, I comply. I do note it at least once in my report, for CYA purposes, and alert my employer. In this case, I am not sure that even that would cover me in a court of law, but there is nothing else I can do. Many times the EOR lets things go, because he really doesn't need full compliance with some code requirement. Under the law, the EOR can allow conditions contrary to the code requirements based on engineering judgement.
Joe,
I can understand how frustrating it can be if the EOR will not back you up. Glad to hear you have your CYA records in good order.
But it seems to me you have a different type of problem than the one I was targeting. If, as you say, it is necessary to run full length tacks, then per AWS 3.0 there is no code circumvention and nothing to enforce, and therefore as an inspector, at least on this issue, your responsibility is fulfilled.
The problem of viability is up to the EOR. Having said that, I have never had any problem with an inspector, certainly not one as obviously experienced as yourself (though I've known many that were better off keepin their pie hole shut) opening a dialogue with the EOR to keep them abreast of any possible issues. I think keeping the EOR and your employer abreast IS an inspector responsibility.