Qualification System Relating To The Establishment Of N. 2 (Two) Distinct Lists Of Qualified Economic Operators For The Supply Of Spheroidal Cast Iron Joints Or Steel To Be Used On The Conduct Of Drinking Water And Gases Distributed Within The Territory Managed By Hera S.P.A. And By The Companies Of The Hera Group - Tender 25_11870 - Rdi 25_400.