Stress Engineering Services (SES) follows a five-step process to detect, evaluate and repair pipelines. The company’s engineers tend to be conservative in the early stages of its Engineering-Based Integrity Management Program (EB-IMP), according to Dr. Chris Alexander, principal at the consulting firm and head of its onshore pipeline practice. With each subsequent level, the company is able to evaluate the severity of the damage and provide operators information about whether the pipeline can continue to operate or if a repair is necessary. Here is how Stress Engineering works with pipeline companies to provide guidance so they can keep pipelines up and running:
OK, inspection technology has found an anomaly. Using industry-accepted assessment methods, SES looks at what the pipeline codes and standards (like ASME B31.4 for liquid pipelines and ASME B31.8 for gas pipelines) say about what is an acceptable defect. If the defect falls within specified acceptable parameters, no repair is required. If not, it’s on to the next step.
In this second level of evaluation, SES researches the defect to assess severity, based on experience, operating history, testing and analysis. If it still does not meet industry requirements, the company continues its evaluation.
SES conducts computer modeling to further evaluate the damage and to define acceptability based on codes, standards and governmental regulations. If modeling shows the pipe does not meet industry standards, the company moves on to full-scale testing.
In the fourth level of EBIMP, SES conducts full-scale testing to validate the results of the preceding steps and, if necessary, to begin engineering a repair solution, which may include a composite material to repair the damage or require replacing the pipe altogether. The assessment of the repair solution is the fifth and final level of the EBIMP process.
5. Restore Service
Once SES designs the repair, the company conducts tests to reestablish pipeline integrity before it is returned to operation.
“One of the very important things in this process is data collection,” Alexander says. “We have to get as much information as we can about the defect. The more you know, the less conservative that you have to be.”
In 2008, Alexander published a paper titled, “Elements of an Engineering-Based Integrity Management Program” with his fellow SES colleague Ron Scrivner. The paper gives further details about the importance and benefits of implementing EB-IMP, with an extensive overview of the five steps.