BS EN ISO 27509:2020

What is ISO 27509 about? 

ISO 27509 is an international standard on petroleum and natural gas industries that covers compact flanged connections with IX seal ring. 

ISO 27509 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 nominal sizes from DN 15 (NPS ½) to DN 1200 (NPS 48), and for CL 2500 (PN 420) for nominal sizes from DN 15 (NPS ½) to DN 600 (NPS 24).  

NOTE: ISO 27509 is applicable to welding neck flanges, blind flanges, paddle spacers and spacer blinds (paddle blanks), valve/equipment integral flanges, orifice spacers, reducing threaded flanges and rigid interfaces for use in process piping for the petroleum, petrochemical and natural gas industries. ISO 27509 is applicable within a temperature range from −196 °C to +250 °C. 

NOTE: ISO 27509 is not applicable for external pressure. 

Who is ISO 27509 for? 

ISO 27509 on petroleum and natural gas is relevant to: 

• Petroleum and natural gas industries 
• Manufacturers of pipes 

Why should you use ISO 27509? 

Compact flanged connections is a non-gasketed bolted static pipe connection including two flanges and where the bolt loads are transferred through metal to metal contact between the flange faces. ISO 27509 provides the general requirements and principles of design of the flange face which includes two independent seals, a force-controlled heel seal, and a displacement-controlled seal provided by the seal ring to prevent corrosion of the flange faces, the stressed length of the bolts and the seal ring. Also, provides the dimensions of flanges and seal rings. 

ISO 27509 provides the designation and materials used for the manufacturing of flanges and IX seal ring seal rings. CFCs shall generally have a level of structural safety so, this document gives the measure of strength, pressure/temperature ratings and leak tightness. 

Furthermore, ISO 27509 help you in manufacturing, testing and inspection of compact flanged connection pipes IX seal rings for petroleum and natural gas industries to ensure the safety of the environment, fittings of bolts and the organization's quality management systems. 

What’s changed since the last update?  

BS EN ISO 27509:2020 supersedes EN ISO 27509:2012. BS EN ISO 27509:2020 includes some technical changes with respect to EN ISO 27509:2012. These include: 

• Ultrasonic testing of products in accordance with new requirements in ASME VIII div. 2 
• Requirements to material strength and machining strictly in accordance with given tolerances for IX seal rings and new and better coating requirements for IX seal rings 
• Excluding use of IX seal rings to assist alignment by transfer of significant shear load during assembly 
• More comprehensive and detailed guidelines on the evaluation of damages to products and the repair of such damages and requirements to the qualification of bolt tensioning procedures 
• The elastoplastic deformation of flanges by the first assembly has been better explained in order to prevent unnecessary re-machining or rejection when flange bevel angles have changed.