What level of material traceability ids required for API 650 tanks?

[mkhangholi]

We have supplied an API 650 storage tank in loose plate to a site in north Alberta canada. Plates are 350WT cold weather steel. we provided whole MTRs to client but we can not exactly tell them each part made out of exactly which heat #. they refer us generally to appendix n of API 650 and claim that there should be exact piece mark trace-ability for each piece of plate. is it true? I think what they claim is an ASME VIII requirement not API650. am I right? How to convince them.

 

[fegenbush]

Are the plates already painted? If not, they can use the markings on the steel to trace back to the MTRs you have provided.

 

[mkhangholi]

Problem is that we have piles of similar plates (24 pcs each) with similar marking, i mean there is no sequence # marking fr each every. they say we want each every piece with unique sequence # which enables trace ability to heat # for that specific piece. is this something per API650? I am sure what they are asking is applicable to nuclear or pressure vessel but not atmospheric api tank. What is trace ability identification requirements for API 650 equipment?

 

[valleytank]

Requirements for material traceability are not specified in the code other than every material must be identified and if it cannot be... to follow Appendix N and Purchaser specifications/requirements.

Due to this plate being for cold service hence the impact requirements (350WT) this makes traceability that much more critical for the client. Each plate should have low-stress stampings with supplier name, Heat/Batch #'s, Job/Tank # etc and how it correlates to your plate run-off drawings and plan views for a material map.

Ultimately this will come down to probably looking through old purchase orders and plate cut lists to identify these stacks of plate. Are you using other grades on the same job?

 

[mkhangholi]

No Other grades used for this project. all the material have MTRs with charpy results all fine. During fabrication We stamped all the cut plates with part numbers specified on the drawing. However, all the similar plates have the same part # and we didn't put sequence #. for example we have 48 similar plates with part # 7000- A, 48 pieces 7000- B,... and so on. Client claims that although theses are similar, we need sequence # to trace them to specific Heat # on MTRs( 7000-A-01, 7000-A-02,7000-A-03, ...). When we ask their reference for such a expectation they just refer us to API 650 App N. However App N doesn't show such high level trace ability which we believe applies just to nuclear pressure vessels not atmospheric storage tanks. API 650 just requires using "identified" plates and once we have materials from accredited suppliers and with proper paper work, it is considered "Identified". after that there is nothing in API about trace ability. But they just insisting ...