Design of Compact Flange Joints

In the past 10–15 years, flange joints designed for metal-to-metal face contact with self seating and pressure activated seal rings have been used extensively in high-pressure applications in industrial piping, pressure vessels, pipelines, risers and associated equipment. These flange joints are generally much smaller and lighter, with smaller bolts, than equally rated standard gasketed flange joints, and are often called compact flange joints. This paper provides all necessary information to design compact flange joints for pressure and external loads and made from any suitable material. The paper includes design methods for design of the seal ring, flange and bolts in addition to assembly guidelines. Weld neck flanges, where the hub is of uniform thickness are discussed in detail. Similar method as presented has been applied to design compact flange joints with great success for many years.