Although inspection is a key element of the integrity management process, it is important for effective integrity management to understand the meaning of inspection results and how they should affect repair and mitigation planning.
The oil and gas industry and chemical process industries use the Fitness for Service (FFS) standard as best practice to assess the suitability of in-service equipment for continued operation. Engineers can differentiate between acceptable and unacceptable flaws and damage using FFS, which provides a rational basis for defining flaw acceptance limits based on widely recognized and accepted good engineering practices (RAGAGEP).
Fitness-For-Service, API RP 579-1/ASME FFS-1, is one example of an FFS methodology currently employed by professionals in the industry. The majority of FFS assessment standards are typically divided into several levels. The referenced API 579-1/ASME FFS-1 standard has three levels, with each level requiring more data, calculations, time, and money to reach the most accurate results and, potentially, a longer equipment remnant life. For example, Levels 1, 2, and 3 of the standard. FFS involves the consideration of additional data in addition to calculations (e.g. pitting patterns and depths, corrosion morphology or shape and depth, crack depths and lengths, operating conditions, materials properties, etc.). Information from inspections is frequently a crucial component of an FFS assessment.
There are several ways to protect pipelines from deterioration. Cathodic protection systems and protective coatings, for instance, are intended to reduce corrosion. However, these protective systems’ efficacy may deteriorate over time, and structural flaws may appear, adversely affecting the assets’ dependability, safety, and performance.
Therefore, important questions must be addressed when defects are discovered during an inspection. Is an asset’s integrity currently in danger? Can I predict the rate of growth of a detected defect in order to determine whether it will get bigger and, if so, when it will become a threat to my asset? How did this flaw start, and will there be other flaws of a similar nature in the future? And of course, is there anything that can be done to prevent the emergence of new instances of these flaws?
These issues are getting more and more important as assets in the global oil, gas, and related industries continue to age. For them to continue operating safely and dependably, a thorough examination, inspection, and integrity assessment are essential.
Basic Fitness-for-Service FFS Program
A standard set of data is typically required for FFS assessments, including the original design specifications, the construction materials, and the history of use and maintenance. Even though many facilities include this information in their standard record-keeping procedures, it is not always simple to access. There are three progressive assessment levels to choose from:
Level 1 Fitness-For-Service FFS Assessment
Assessments at Level 1 require the least amount of knowledge and experience. There aren’t many computations needed for this kind of assessment, which typically uses tables and screening curves. This indicates that the calculations may be quite conservative, much like the calculations used in design codes. The duration of this level of inspection is typically shorter than the other two.
Level 2 Fitness-For-Service FFS Assessment
A Level 2 assessment can be carried out if a Level 1 assessment of a piece of equipment falls short of the required standards. To replace the straightforward, conservative computations that make up the Level 1 assessment, a Level 2 assessment necessitates considerably more complex computations. However, because the calculations are so complex, FFS software is frequently needed. The advantage is that using fewer conservative calculations may result in better results.
Level 3 Fitness-For-Services FFS Assessment
In most cases, Level 2 assessment criteria are satisfied, allowing for the equipment to be put back into use. A Level 3 assessment, however, might be necessary in extreme cases. A Level 3 assessment requires more precise data than the previous two levels and a significant amount of operational experience on the inspector’s part. Because of the potential for errors when using more sophisticated equipment, Level 3 analyses are rarely performed. The quantity of data available for evaluation, the quality of that data, and the degree of significance of the analysis to equipment operations are all factors that influence the choice of a level of FFS.
Conclusions about FFS assessment
Implementing an FFS program as a component of a reliability management program aids in easing budget acquisition and assessment completion time difficulties. Before a shutdown, you can save time by gathering the information needed to conduct the assessment.
Time and money can be saved by incorporating fitness-for-service technology and assessment capabilities into routine maintenance programs. Making sure that these resources are included in the maintenance program budget can stop shutdowns from extending and possibly stop unanticipated shutdowns.
