This International Standard specifies detailed manufacturing requirements for circular steel and nickel alloy
compact flanged connections and associated seal rings, for designated pressures and temperatures in class
designations CL 150 (PN 20) to CL 1500 (PN 260) for nominal sizes from DN 15 (NPS ½) to DN 1200
(NPS 48), and for CL 2500 (PN 420) for nominal sizes from DN 15 (NPS ½) to DN 600 (NPS 24).