Life estimation of pressurised pipe bends using steady-state creep reference rupture stresses

Steady-state reference rupture stresses were obtained for a range of 90° pipe bends, subjected to internal pressure only, using simplified 2D axisymmetric finite element (FE) models. The bends were considered to be circular in shape and not include any ovality. Creep damage FE analyses were performed to obtain realistic failure lives and to determine the skeletal point rupture stresses, using the material properties, obtained at 640 °C, for a service-exposed CrMoV pipe steel. The effects of the normalised pipe bend dimension on the reference rupture stresses are presented. The results obtained confirm the validity of the use of the steady-state reference rupture stress in life estimation for a wide range of pressurised pipe bend geometries. The life predictions were compared with those of the corresponding straight pipes and their relevance considered. [Copyright &y& Elsevier]