The International Organization for Standardization (ISO). This ISO document is a Draft International Standard. ISO/TC 153/SC
1. Voting begins on: 2011-12-21, Voting terminates on: 2012-05-21. This second edition cancels and replaces the first edition (ISO 10631:1994), which has been technically revised. 20р. This international standard specifies requirements for the design, materials, pressure-temperature ratings and testing of butterfly valves having metallic bodies for use in flanged or butt welding piping systems and used for general purposes.