Residual Stresses in 3LPP Pipeline Coatings

Three layer polypropylene coating has been used for high temperature coatings in both onshore and offshore applications.  In the past few years, two critical performance issues relating to coating disbondment and cracking have been observed in the field.  Two possible root causes of failure due to residual stresses and adhesion loss have been reported in the literature.  In this paper, we will analyze the effect of residual stresses on coating performance and their impact on coating failure mechanisms.  Both analytical and finite element analyses will be used to assess the residual stress distributions and their effect on coating failure.