ANSI/ASME B16.47 standard covers pressure-temperature ratings,materials,dimensions,tolerances,marking, and testing for large diameter steel flanges in sizes NPS 26 through NPS 60.It includes weld neck flange and blind flange.Series A contain weld neck flange and blind flange in ratings Classes 150,300,400,600,and 900,Series B in rating classes 75,150,300,400,600,and 900.Flanges may be cast,forged,or plate (for blind flanges only) materials.Requirements and recommendations regarding bolting and gaskets are also included.