Ageing of pipelines raises a major concern for liquid pipeline operators such as TRAPIL, which have to constantly adjust their integrity management practices to the growing knowledge in the field of defect assessment. In the case of TRAPIL, improvement of this knowledge arises from rigorous comparisons between in-line inspection (ILI) and field experience. However, as French regulation is also refining its recommendations over time, how does TRAPIL adapt its integrity management to fulfill all requirements ?

The first part of the article provides an in-depth description of TRAPIL defect management process, divided in three successive steps. The first step includes the analysis of ILI data, that results in excavation recommendations. The second step is the excavation itself, during which non-destructive tests are carried out on field in order to state on defects acceptability. The third step of the process consists in the validation of the pigging tool.

During an excavation, at TRAPIL, it may become necessary to grind a tube under pressure to remove indications and prevent their expansion. Grinding is challenging regarding legal requirements and health aspects, which has led to the development of new tools that are presented in the rest of the article.

Indeed, French regulation defines a criterion that has to be met when grinding, ensuring the softening of the resulting profile and a reduction of the stress concentration zone. To comply with this criterion, TRAPIL has developed a software operating with on-field data that is able to assess grinding acceptability within a few minutes according to the regulation.

Moreover, grinding may be dangerous for technician health when conducted too often or for too long, due to the vibrations it causes. Solutions have been developed to allow for both a significant reduction of vibrations and a better control on the grinding profile.