In order to ensure that gas transport lines operate with as little damage and environmental impact as possible while being economic, Thyssengas GmbH operates a Pipeline Integrity Management System (PIMS). The task of the PIMS is to determine the overall process for the assessment of the integrity of lines and thus to control the operative implementation of inspections, maintenance, and repairs of the line network.
In this connection, Thyssengas GmbH introduced a Pipeline Integrity Management System in 2010. The goal was to provide technical system support for the PIM sub-processes "determination of line condition" and "suggestion for the assessment of the line condition". Thyssengas focused on a convergent integration of the PIMS into the existing operational processes.
During an intensive specification phase Thyssengas developed evaluation algorithms to perform the integrity assessments based on current regulations. The technical assessment developed in this way includes line classification, stress assessment, and a ranking system.
Line integrity is assessed using the stress evaluation developed as part of the project. It determines the relation between stress and resilience of the line under consideration. The result is compared to pre-determined threshold values, allowing one to make a decisive statement concerning the integrity of the line.
In addition, a ranking system was defined that determines reconstruction priorities. The ranking system determines characteristic values, weighted using utility value functions. The characteristic values help in the selection of suitable inspection methods and repair measures.
Another focus lay on the development of a corrosion evaluation. A prognosis of the possible corrosion damage is calculated using the applied construction standards, soil information, and the history of the corrosion protection. The system is able to deliver best-possible estimates of corrosion damage even without confirmed input data.
The evaluation algorithms and other individual functions were implemented and configured based on the standard software Trascue PIMS. The input data are mainly consolidated in Smallworld GIS.
PIMS was started up in April of this year. At the moment we are performing line evaluations and the results are used to validate the current PIM processes and the evaluation algorithms.