This European Standard specifies requirements for PN designated circular flanges for pipes, valves, fittings and accessories made from aluminium alloy in the range of DN 15 to DN 600 and PN10 to PN 63 (see Table 1). This European Standard specifies the types of flanges and their facings, dimensions and tolerances, bolt sizes, surface finish of jointing faces, marking and materials together with associated pressure/temperature ( p/T) ratings. The flanges are intended to be used for piping as well as for pressure vessels.