TRACK: Safety/Reliability
Industry standards like ASME B31.3 for Process Piping and NEMA SM23 for mechanical equipment establish guidelines for stress limits and allowable nozzle loads to ensure system reliability. Expansion joints play a vital role in piping systems by absorbing thermal expansion and reducing mechanical stress, providing necessary pipe flexibility and ensuring compliance with these limits. Without them, process piping and equipment such as steam turbines and turbo-expanders could be exposed to excessive forces, leading to irreversible damage and premature failure. Metallic expansion joints are designed according to the Expansion Joint Manufacturers Association (EJMA) standards. When calculating reaction moments, these standards primarily consider the bellows spring rate and pin friction. However, relying solely on these parameters can lead to an underestimation of other crucial forces that influence the expansion joint’s behavior. This presentation explains the various reaction forces acting on Gimbal and Hinged metallic expansion joints during angular movement, emphasizing the lateral pressure force. Understanding this force is critical for more accurate moment calculations and safer designs. Furthermore, this presentation will cover best practices for designing Hinged and Gimbal joints to ensure optimal performance.