This European Standard specifies minimum general requirements for butterfly valves having metallic bodies for use in wafer, lug, flange or butt welding piping systems and used for isolating, regulating or control applications. The PN and Class ranges are: PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100; PN 160; Class 150; Class 300; Class 600; Class 900. The DN range is: DN 20; DN 25; DN 32; DN 40; DN 50; DN 65; DN 80; DN 100; DN 125; DN 150; DN 200; DN 250; DN 300; DN 350; DN 400; DN 450; DN 500; DN 600; DN 700; DN 750; DN 800; DN 900; DN 1 000; DN 1 100; DN 1 200; DN 1 400; DN 1 500; DN 1 600; DN 1 800; DN 2 000; DN 2 200; DN 2 400; DN 2 600; DN 2 800; DN 3 000; DN 3 200; DN 3 400; DN 3 600; DN 3 800; DN 4 000. DN 750 is used only for Class 150 and Class 300. NOTE Intermediate DNs are allowed upon agreement between manufacturer and customer. For valves subject to Pressure Equipment Directive, EN 16668 applies together with this European Standard. For industrial process control valves, EN 1349 and EN 60534-2-1 apply together with this European Standard. For water supply application, EN 1074-1 and EN 1074-2 apply together with this European Standard. The correspondence between DN and NPS is given for information in Annex D.