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Up Topic Welding Industry / ASME Codes / Questions concerning weld process to be used ASME VIII Dev 1
- - By Jmerz2046 (*) Date 02-06-2018 02:35 Edited 02-06-2018 03:51
Hey y’all,

Keep this short and sweet. Is there anything pertaining to the code of construction for ASME VIII DEV. 1 that states what weld process is to be used, or isn’t to be used, pertaining to CJP Groove welds for carbon steel pressure vessels? I couldn’t find anything that states, for instance, if tig or stick is to be used when welding any size diameter. Is there somewhere else I should be looking? Customer is saying that a certain diameter groove weld needs to be complete TIG. (After the fact that weld maps and WPS’s were given to the customer prior to fabrication, and OKAYED!) I cannot find this written into the code. I would like to make sure that this is or isn’t in the code.Your help is appreciated.

Thanks....
Parent - - By 803056 (*****) Date 02-06-2018 15:26
ASME goes out of their way not to dictate how a vessel is to be fabricated. There are a few joint details that are prohibited, but other than that, the contractor is free to use any means or methods they can demonstrate will produce the required mechanical properties.

Al
Parent - - By Jmerz2046 (*) Date 02-06-2018 18:48
Al,

So if I understand you correctly, as long as we issued the customer a qualified WPS (and the weld joint and material by the way are a 1/2"-150 W.N.R.F. Flange welded to a pipe @ .840" O.D. x 0.147" Wall, with "CJP" SMAW for the weld process) and the customer OKAYED the WPS and weld maps, we as the fabricator, can go ahead with the weld process that was qualified ,( as long as we can demonstrate the weld process will produce the required mechanical properties, thus the WPS) and the code of construction, ASME VIII DEV. 1, doesn't dictate how or what the weld process should be? The information provided to us by the customer, doesn't say any other ASME code to comply with, such as ASME B31.3 or B31.1, so i was thinking maybe because of the flanged joint connected to small diameter pipe, they are looking at the ASME B31 series, for some reason. I'm not really a mind reader if that is supposed to be the case. I do think that I read somewhere that the ASME B31 series calls for root pass to have a slagless process (TIG welded) in some cases, but don't think that would concern us in this case. We completed the fabrication and few months down the road the engineer made the call that the process should of been TIG for the material that I previously stated, after the WPS was OKAY and fabrication completed. Now, we are stuck with the task of reworking the previously OKAYED  weld. I can understand that the customer wanted the TIG process for that particular weld joint but they shouldn't of OKAYED the WPS and WELD MAPS if that was a concern. I was under the impression that we were going to receive payment for this rework ( not repair) but the engineer for the customer is insistent that we should have none better. :-) So i can ask the engineer to show me were in his code book, that it states, what weld process is to be used for any given diameter, with "CJP", and  he will not be able to produce such a thing? Under any ASME code?

Thanks...
Parent - - By 803056 (*****) Date 02-06-2018 19:08 Edited 02-07-2018 04:19
You hit the nail on the head, you are not a mind reader nor should you be expected to.

Did the customer provide you with a project specification? Did they tell you to qualify your welders and WPSs per ASME Section IX? Did they tell you that the construction code was ASME B31.1 or B31.3?

If they didn't provide you with the information I listed, shame on them. You owe them nothing more than what the drawings specified.

B31.1, nor B31.3 require the contractor to use GTAW, GMAW, SMAW, or SAW. The welding process is determined by the contractor unless there is a project specification that restricts what welding processes can be used.

If the customer's representative is finding the work to be unacceptable, he should be able to show you in the applicable code where it is not permitted. Woo, hold on a minute; they didn't state which construction code applies in the PO or project specifications? He has no legs to stand on, he owns it.

Best regards - Al
Parent - By Jmerz2046 (*) Date 02-06-2018 19:32
Al,

Thanks for your valued input. I appreciate you taking your time out of your day to speak with me on this matter. Till next time!

Thanks,
Jmerz2046
Parent - By weldnote (*) Date 02-13-2018 16:01
Let me add something to what Al said.

The welding processes to be used do sometimes come in project specifications and you will know this before there is any sort of quotation or purchase order on the project. Frequently the purchasers will define if they want root passes with TIG, or if they want to forbid GMAW in production (I've seen this in some specifications).

If the specification says nothing, then it is as Al said, tough luck. The construction standards do not restrict on these processes. If you have qualified WPQR's and approved WPS' then you can just carry on with the work. If the client demands that TIG welding be done from here on out, by all means do so, but the price is now going to be X thousand dollars more.

TIG is a slow process, and if your company's pricing is based on your SMAW / GMAW / Whatever processes, you will lose money if you succumb to these requests.

This is a no brainer, and you're in the right, just provide all the documentation (including the WPS with your client's signature of approval), and they will have to accept it.

P.S. I've done a search through ASME VIII and the only mentions of slag are when using electroslag process, or when having slag inclusions in the weld, which I suppose is not the case :)

Best regards
Up Topic Welding Industry / ASME Codes / Questions concerning weld process to be used ASME VIII Dev 1

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