Computational analysis of internal stresses generated during the manufacturing process of a monolayer or three-layer pipeline coating

Failure Analysis of Disbondment of Three-Layer Polyethylene Coatings from the Surface of Buried Steel Pipelines

“…However, as mentioned, the disbondment of the organic coatings under operating conditions of the buried pipelines could involve a number of chemical, physical, and mixed complex phenomena. According to the literature, it has been reported that different thermal contraction coefficients between steel and thick polymer coatings can generate residual stresses at the metal-polymer interface during the cooling stage of the coating process [7,8]. These residual stresses are generated before pipeline installation, while the observed failure started to develop after a short period of time following the in-service life of the pipeline.…”

“…The 3LPE-coated steel pipes are frequently used as pipelines for oil and natural gas transportation. Over the last several years, there have been many reported failures involving adhesion of the 3LPE coatings to the metallic surface of steel pipelines [6][7][8][9][10][11][12]. The poor adhesion of the 3LPE coating to steel pipelines has been reported in all areas of the world where these coatings are used [13].…”

Stress evolution in multilayer polymer coating under thermal and pressure loading applied to the pipeline structure

“…Moreover, to our knowledge, there has been no such case of reported damage on pipelines coated with monolayer epoxy systems while these systems are also sensitive to water diffusion. Legghe et al [20], with a numerical approach, have estimated the internal stresses levels generated during the processing of monolayer and three-layer coated pipelines. Considering an elastic behaviour (more unfavourable case -without dissipation) in a first approximation, the authors obtain a large gap (x4) between stress levels in both systems.…”