Graphene is a bit of hype intensive research right now. Mostly because the promises made for CNTs didn't ever materialize.
Bill Riehl, PhD, PE
Blackfire Engineering
Need more information. RSI is a conglomerate value. Do you have a real water analysis?
And by carbon steel, do you mean black pipe? Or seamless? Or welded? Need more info to help.
Bill Riehl
Riehl Engineering