Implementation of RBI at an LNG Facility
In this case study, we will discuss the implementation of Risk Based Inspection (RBI) at an LNG facility. The main objective of the RBI implementation program was to develop an ongoing and sustainable asset integrity management program that would identify and prioritize the equipment that had the highest risk of failure, based on a systematic and quantitative approach.
RBI Implementation Program
To commence the RBI implementation program, Metegrity consulted with the client to gain an understanding of their facility and equipment types. Next, they determined which equipment would be included in the scope of the study. With that completed, the implementation team from Metegrity configured Visions Enterprise® to oversee the data input for the RBI assessments. The team then formulated a plan, evaluated various models, and established a strategy for executing the work.
Organizing data is a crucial step in RBI implementation. Fortunately, in this case, the facility was almost new, and most of the information was in electronic format. The team worked with master lists, process flow diagrams, heat material balance sheets, and specification sheets to understand how each plant was being operated as well as the fluid compositions, materials, and dimensions. The data was organized into equipment types per operating plant, with each folder containing equipment numbers and categorized data for the study which was validated and documented.
Developing Corrosion Control Documents
The scope of the implementation program included the development of Visions Enterprise® Integrity Manuals, aka, Corrosion Control Documents (CCD). These Integrity Manuals were developed based on the API standards. The strategy breaks down the individual plants into corrosion loops. Each loop includes equipment in a common operating environment together with the potential or acting degradation mechanisms.
The team proceeded to write these documents, 15 in total, which included process summaries, process descriptions, feed sources, corrosion loops or circuits, and identifying degradation mechanisms. The document included information regarding where and how to inspect for each mechanism and how to monitor the equipment condition, preferably onstream using various NDT methods. IOWs were also included to monitor the process and provide feedback concerning the integrity of the equipment.
As part of the RBI program, an RBI model was needed. The team after considering several models chose the standard Visions Enterprise® semi-quantitative model which was modified to meet client’s specific needs. The team performed the RBI assessment using the Visions Enterprise® software, and the results were documented and applied directly in the program. Several equipment items that required immediate attention were identified. Metegrity then developed an Asset Integrity Management program to manage these risks, which included the development of inspection plans, periodic inspections, repairs, and maintenance. A second model at client's request was also developed to perform risk assessments on pressure safety valves.
Metegrity provided the client with a detailed plan that outlined the essential steps to ensure the safe and reliable maintenance of the equipment.
The Metegrity team returned to site 7 years later to perform an audit on the effectiveness of the program. Minor changes were required. The RBI assessments were redone, and results immediately applied to the equipment. The results were an up-to-date schedule for future inspections based on risk.
In conclusion, the RBI program implemented at the LNG facility was successful in identifying and prioritizing equipment items that required immediate attention. The RBI program's success was due to the systematic and quantitative approach taken, as well as the organization, validation, and documentation of the data. Visions has an interface with OSIsoft PI, which can manage IOWs and provide feedback concerning the integrity of the equipment. Using Visions can improve the efficiency and accuracy of the RBI implementation program.