In order to solve the problem that the API-579 can only assess the residual strength and safety of the metal pressure pipeline under one of the given eight modes, the concept of area occupation ratio of pitting was proposed. The corresponding relationship between area occupation ratio of pitting and remaining strength factor and ratio of the remaining wall thickness to the future wall thickness was built respectively. Furthermore, a non-discrete characterization model of residual strength was proposed. The model could be used not only to assess the residual strength but also the safety of the pipeline with pitting corrosion under the eight modes given in API-579 standard. The model made it possible to predict the dynamic remaining life of the pipeline with pitting corrosion.
