This Standardcovers Classes 25, 125, and250 GrayIron Pipe Flanges and Flanged Fittings. It includes
(a) pressure–temperature ratings
(b) sizes and method ofdesignatingopenings ofreduc-ing fittings
(c) marking
(d) materials
(e) dimensions and tolerances
(f) bolting and gaskets
(g) pressure testing
