we're designed the pressure vessels
material SA516-60
thickness 47 mm
we're have to PWHT and then should be Hardness. So I would like to know about reference to code for hardness and How much value hardness?
However, if you were to do the hardness testing anyway, the hardness values can be found in API Recommended Practice 577. Look up Table-11 on page 63. Section 10.3 is entitled "Hardening".
Of course, this depends on the process... is it Hydrogen or Sour service? Are the plates HIC tested or should be?
Did you throw an eye on the project specifications? Most of the times, client sets the required hardness value... In my mind, I always keep that 200 HB for P No1 material, although it is not always mandatory...