This Standard for Classes 25, 125, and 250 Cast Iron Pipe Flanges and Flanged Fittings covers: (a) pressure-temperature ratings, (b) sizes and method of designating openings of reducing fittings, (c) marking, (d) minimum requirements for materials, (e) dimensions and tolerances, (f) bolt, nut, and gasket dimensions and (g) tests.
ASME B16.1-2005 history
2020ASME B16.1-2020 Gray Iron Pipe Flanges and Flanged Fittings Classes 25, 125, and 250
2015ASME B16.1-2015 Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250
2010ASME B16.1-2010 Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250 (B16.1 - 2010)
2005ASME B16.1-2005 Gray Iron Pipe Flanges and Flanged Fittings: Classes 25, 125, and 250
1998ASME B16.1-1998 Cast iron pipe flanges and flanged fittings - Classes 25, 125, and 250
1989ASME B16.1-1989 Cast iron pipe flanges and flanged fittings