Assessment of Long Corrosion Grooves in Line Pipe

Due to coating disbondment long corrosion grooves can develop in line pipe. For simple corrosion geometries current methods of assessing the residual strength of the pipe are adequate but conservative, particularly if only the nominal material strength is considered. In the case of long corrosion grooves which contain pits the application of current assessment procedures can lead to a variation in the degree of conservatism, depending on the importance applied to the pitting. This paper reviews existing methods of assessing long corrosion and describes the result of a finite element study of pits within long corrosion grooves.