ASTM material or S275 J2 Design Code for Structural Steel Materials

[Asya]

Bidder proposes ASTM A36 material instead of S-275 J2 or S355ML/NL for structural steel (Piperack, Equipment Structure, etc.) on the basis of international standards for most optimal and economical design. Which one? help

 

[BigInch]

I've used A36 to design numerous miles of pipe racks.
Yield strength is 36,000 psi

No reason other structural steels could not be used, as long as they are sized properly according to their respective yield strengths.
I suggest the bidder proposed this because he can build equally as well and cheaper too.