ISO 10631:2021

This document specifies the general requirements for design, materials (e.g. steel, cast iron, ductile iron, copper alloy), pressure/temperature ratings and testing for butterfly valves having metallic bodies for use in flanged or butt-welding piping systems.
This document applies to metallic butterfly valves used for all industrial applications.
Additional requirements given in the relevant application standards can apply to butterfly valves used for more specific applications (e.g. for the water industry, the chemical and petrochemical process industry, the oil and gas industry).
This document covers butterfly valves of the following nominal sizes, DN and NPS:
-  DN 40; 50; 65; 80; 100; 125; 150; 200; 250; 300; 350; 400; 450; 500; (550); 600; (650); 700; 750; 800; 900; 1 000; 1 050; 1 200; 1 400; 1 500; 1 600; 1 800; 2 000; 2 200; 2 400.
-  NPS 1 ½; 2; 2 ½; 3; 4; 5; 6; 8; 10; 12; 14; 16; 18; 20; (22); 24; (26); 28; 30; 32; 36; 40; 42; 48; 54; 56; 60; 64; 66; 72; 78; 80; 84; 88; 90; 96.
This document is applicable to butterfly valves of the following pressure designations, PN and Class:
-  PN 2,5; PN 6; PN 10; PN 16; PN 25; PN 40; PN 63; PN 100;
-  Class 25, 125; 150; 250; 300; 600.
NOTE 1   It is possible that the nominal sizes listed are not available for all pressure designations.
NOTE 2   Nominal sizes listed in parenthesis are not common industry sizes, but are used in some application standards.