sa 517 gr a

ELEMENTSGRADE A %GRADE B %GRADE E %Heat analysis0.15-0.210.15-0.210.12-0.20Product analysis0.13-0.230.13-0.230.10-0.22Heat analysis0.80-1.100.70-1.000.40-0.70Product analysis0.74-1.200.64-1.100.35-0.78See all 37 rows on aasteelAzom Admin · Masteel UK LtdThe differences in alloy content are not intended for corrosion resistance. The amounts in Grade E won't buy you much anyway. The alloying is done for hardenability reasons. The difference between B and E composition is considerable in that respect. That said, I don't understand why Table 2 shows common tensile requirements for all six grades. "If you don't have time to do the job right the first time, when are you going to find time to repair it?"First, this is a pressure vessel under Section VIII, Div 1 which would require review of ASME Section II, Part D for permitted material for pressure retaining service (Grades A, B and E) and allowable stresses. With that said, the selection should be based on allowable stress value (to minimize wall thickness) and weldability (PWHT concerns). Look at Table 1A in Section II and compare between listed Grades of SA 517 material, in lieu of the mechanical properties in SA 517 directly.Section II shows identical values for both grades in the temperature range I am concerned with (-20°F - 125°F). Section VIII Part UHT has the same PWHT and essential variable requirements for both grades. In essence the ASME Code makes no distinction in how the two grades are treated. The only difference is that Grade E is a P-No. 11B Gr. 2 material and Grade B is a P-No. 11B Gr. 4 material. My processes will likely be warm or hot forming of the head sections by a third party, cold working of the shell, tear-off pads, etc., flame and mechanical removal of material, FCAW and SAW, and PWHT. With these processes in mind, is there one of these grades that will give my welders and fabricators fewer headaches?I would use SA 517 Grade B.Thank you for the help. I'm going to see what the availability is like for the Grade B.