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Currently building a 40.000 m3 crude tank

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Maxvolonte

Petroleum
Sep 30, 2017
12
thread1452-421887 hello colleagues. I work for Axion energy (former Exxon) here in Argentina. We currently building a 40.000 m3 crude tank. I have the contractor site manager and owners debating me about the NDE required on the Shell connections at the first course. These are 3 8" connections, one of them for the swamp, and they have LTR. I have asked the contractor to MT the root before proceeding with filling of the Groove and they just ignored me. I have asked them to MT the cap or final pass, and they are ignoring me as well. I am about to write down an NCR, but before I proceed with it, I need advices. My understanding is that these type of connections are treated as Flush type or actually are, and the NDE requirements are the ones mentioned on para 5.7.8.11 of API 650 standard. Contractor keeps saying I am wrong, and they are making a big deal out of it. At the company I used to work before, YPF oil, contractors already knew they had to MT these welds. They want to go by the code, and they told me and my boss, that those are not Flush type shell connections, and they will not perform the NDE required.
First course is 33 mm thick.
Any advise would be appreciated.
Best regards
 
 http://files.engineering.com/getfile.aspx?folder=ea76c836-b376-4de8-b4f3-9d79413ac23d&file=IMG_20180103_102613594.jpg
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The nozzle shown in your photograph is not a flush type shell nozzle. The requirements of 5.7.8.11 are not applicable to it.
 
JStephen is correct, but your relationship with the contractor is unacceptable. You are the owner, they work for you. Being ignored is unacceptable. Boot them off the site if you can. If not, have a good meeting with them and all higher ups laying down the law.
 
Ok colleagues, then there is no nde required on this connections at all? If there's any, where in the standard 650.
Best regards
 
I agree with JStephen and IFR about the code statement about, but as a constructor QA/QC, at least in our company, we do NDT in this type of installation, never the less, this is our company standard, not a code requirement, if it's an exigence of the client I think that they should bargain with you about doing the NDT, I may ask to what group belongs the steel plate.

I also may ask if there is a testing and inspection plan for the constructor or the client have an inner specification about the non destructive testing for those types of weld, just thinking if there any contractual requirement for this type of essay.

I dont know if this paragraph should help you to decide,

"7.2.3.6 The requirements of this section shall be followed when welding to Group IV, IVA, V, and VI materials. Permanent and temporary attachments (see 7.2.1.11 for information on shell-to-bottom welds) shall be welded with low-hydrogen electrodes. Both permanent and temporary attachments shall be welded in accordance with a procedure that minimizes the potential for underbead cracking. The welds of permanent attachments (not including shell-to-bottom welds) and areas where temporary attachments are removed, shall be examined visually and by either the magnetic particle method or by the liquid penetrant method (see 8.2, 8.4, or 8.5 for the appropriate examination criteria)".

There in the Annex T it mentions

"PT Welds attaching nozzles, manways, and clean out openings instead of MT if approved. 7.2.3.6"
 
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