ISO 27509:2012 specifies detailed manufacturing requirements for circular steel and nickel alloy compact flanged connections and associated seal rings, for designated pressures and temperatures in class designations CL 150 (PN 20) to CL 1500 (PN 260) for
DS/EN ISO 27509:2013 history
2020DS/EN ISO 27509:2020 Petroleum and natural gas industries – Compact flanged connections with IX seal ring (ISO 27509:2020)
2013DS/EN ISO 27509/AC:2013 Petroleum and natural gas industries - Compact flanged connections with IX seal ring
2013DS/EN ISO 27509:2013 Petroleum and natural gas industries - Compact flanged connections with IX seal ring