4 replies to this topic

[Vignesh S]

SA-515 is used for intermediate and high temperature service while SA-516 is used for medium and low temperature service.

Both of these materials have almost identical physical properties and chemical composition. Only difference is that carbon content is higher in SA-515 as compared to SA-516

SA 516 is very commonly used pressure vessel plate. What is the temperature limitation for SA-516?

Thanks in advance.

Regards,
Vignesh.

[breizh]

http://www.eng-tips....d.cfm?qid=14909

This link should support your query or try Google (comparison SA 515 versus Sa 516)
Breizh

[Vignesh S]

Thank you Mr.Breizh,

I tried Google. But I can't find the limitation of temperature for SA516...

[breizh]

850 F for SA 516 if my reading (link) is correct and 1000F for SA 515 .
Breizh

[kkala]

Thanks, breizh, for really useful data on SA-515 and SA-516. Attachement from Eng-Tips is interesting.
Low temperature limit of SA-516 can be part of the query too. Googling "SA 516 minimum design metal temperature" returns data on this, although the matter may be a bit more complicated. A few findings:
1. http://www.pveng.com/Sample/AddNozzle/Sample1_APV.pdf. Referred vessel of SA-516 gr B shall have (minimum design metal temperature) MDMT=-20 oF at 100 psi (vessel MAWP) and follow temperature curve B; computed minimum temperature=-43 oF.
2. http://65.57.255.42/ubbthreads/ubbthreads.php?ubb=showflat&Number=7357. ASME VIII div1, UCS-66 contains a graph to specify MDMT, depending on shell / head thickness and qualification of material as A, B, C, D, having separate curves on the graph.
If material temperature can go lower than MDMT, impact test is required (assumed often undesirable).
For 1" thickness: material qualified as A can have MDMT=68 oF, versus -30 oF qualified as D.
SA 516 gr70 can be classified as B in "unnormalized" condition, versus D in "normalized" one.
3. So clarifications can be obtained by going to ASME VIII div1, UCS-66. Local Process does not deal with materials / codes, so I cannot be more specific. Additional advice/comments by others are welcomed.
4. Besides response to following queries (created on the go) can be useful.
4.1 In a basic design of a propylene (normal b.p. = -42 oC) sphere, we had specified MDMT=-42 oC at 0 Barg. It seems necessary to say "at 0 Barg", but why? Wall thickness (of course depending on design pressure) was fixed, so MDMT could be fixed by e.g. the curve D of the proper (steel) material per para 2. In other words, given that MDMT=-42 oC at 0 Barg, what is MDMT for the same vessel at (say) 17 Barg (any difference)?
This could also clarify statement in para (1): MDMT=-20 oF at 100 psi, computed minimum temperature=-43 oF.
4.2 Both SA-515 and SA-516 are killed carbon steels, http://www.onetb.com/forum/difference-between-sa-515-gr-70-and-sa-516-gr-70-t661.html. I had the impression that all killed carbon steels are suitable for low temperatures (down to about -49 oF, depending on grade); http://kolmetz.com/pdf/Design_Guidelines_for_Safety_in_Piping_Network_Rev%20web.pdf may indicate so (page 7). However this is not true for SA-515. Can you advise?
5. Look also at http://cr4.globalspec.com/thread/41704/SA-516-Grade-70-Steels.

Edited by kkala, 26 August 2012 - 11:01 AM.