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Minimum Temperature limit for SA-516-70N

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khanvessel

Mechanical
May 3, 2006
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Hi,

I am working on a PV having MDMT -58 degree F in wet sour enviroment, is SA-516-70 N suitable for this application? What is the minimun temp limit for SA-516-70N and where to find?

Regards
 
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You will require impact testing of the material and weld procedures to establish it is suitable for that MDMT. In regards to sour service, you will want to review NACE MR0175/ISO 15156 and NACE Report 8X194 for general sour service and HIC specific issues.

It sounds like you don't have much experience with this material and wet sour environments so I would recommend you obtain the assistance of someone who is knowledgeable and can assist with developing your vessel requirements.
 
Requirement of Impact test for any material is function of thickness of material & MDMT. Hence there is no such "Minimum temp limit" for any material , as regards to impact testing.

Additionally there clauses for reduction in MDMT mentioned in UCS-66 and UCS-68(c) of ASME Sec Viii Div 1.
As pointed rightly by rneil you can take assistance of experienced vessel design engineer for the job.
 
Generally SA-516 Gr. 70 N has no problem above -45 °C if the requirements of ASME Code are satisfied (like bhushan76 say). In any case, with -50 °C, you must have an impact test at (minimum( -50 °C) and you have to choose the value required (Joule) by the code (or by PED Dyrective if you have to use it).

In any case consider also what say rneill for sour service requirements.

Consider that when you must have an impact test there are also many requirements that you have to consider: production coupon, PQR, WPS with these material, etc.

I hope these information could help you.
 
You should be able to obtain SA-516-70 N that will meet impact absorbed energy requirements at -58F and you should have no problem qualifying impact test weld procedures at that temp.

 
Agree with Stanweld, however, thickness, and PWHT if applicable will affect a materials suitability. I advise that you get all the requirements summarized and talk to a material supplier or better yet the mill because generally there's more than one option.
Arcelor Mittal, formerly Bethlem Lukens, has knowledgeable staff.
 
In Western Canada we regularly use SA516-70N for sour service vessels but you do need to be careful with the detailed specs (chemistry limits, qualification testing, source of supply) and this material may not be suitable in all cases (e.g., heavy wall vessels). Some people do restrict vessel material to SA516-60N as this material is less likely to cause sour service problems.
 
Thank you all for your expert advice, It is recommend in one of our clients spec that if MDMT is below -47 C, clad the vessel with UNS S31254 or use SA 203 Gr D or E with impact and HIC test.

Temp range in ASME II Table A1 is upto -20 F only.


Regards



 
You are about at the practical limit for SA-516-70N, and also -60N for that matter.

It can be done, but you will need to shop for MTRs, not just for PQR purposes but for the production steel, because production tests blocks will be subsequently required. Lower carbon, fine grain size, and Charpy numbers comfortably above the minimum are desirable.

Getting results in the weld is not difficult, it is usually the HAZ that presents the greatest difficulty.
 
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