This European Standard for a single series of flanges specifies requirements for circular steel flanges in PN desig-nations PN 2,5 to PN 400 and nominal sizes from DN 10 to DN 4000. This European Standard specifies the flange types and their facings, dimensions, tolerances, threading, bolt sizes, flange jointing face surface finish, marking, materials, pressure/ temperature ratings and approximate flange masses. For the purpose of this European Standard, "flanges" include also lapped ends and collars. This European Standard applies to flanges manufactured in accordance with the methods described in Table 1. Non-gasketed pipe joints are outside the scope of this European Standard.