- Published on Monday, 30 July 2012 14:56
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A team of Becht engineers, in collaboration with owner/operator personnel, recently completed a successful Risk-Based Inspection (RBI) Assessment and a Turnaround Risk Based Work Selection (TA/RBWS) Assessment for a major complex refinery in the Gulf Coast. These assessments enabled the refinery to closely evaluate a very ambitious work scope for an upcoming turnaround and resulted in a significant savings to the work scope of approximately $10 to $15 million. API inspection codes and standards allow owner/operators the ability to plan an inspection strategy (increase or decrease the inspection frequencies) and/or replace turnaround inspections with alternative on-line risk mitigation approaches based on the results of a risk-based inspection assessment.
These assessments must systematically evaluate both the probability of failure and the associated consequence of failure. The probability of failure assessment must consider all forms of deterioration that could reasonably be expected to affect the piece of equipment in the particular service. The intent of this project was to assist the refinery in finalizing their work scope for an upcoming Turnaround. The assessments included Fixed Equipment, Fired Heaters, Rotating Equipment, Electrical Systems, Motors, Instrumentation, Piping and Valves, and Flare systems which covered a number of Process Units throughout the refinery. The RBI and TA/RBWS assessments included the application of the client’s corporate risk matrix for determination of risk levels and risk reduction. The RBI assessments for Fixed Equipment utilized Becht’s proprietary software tool –STIER© (Strategy Tool for Improving Equipment Reliability). In addition to the STIER© tool, Becht Engineering has a software tool – STRAITS© (Strategy Tool for Risk Assessment for Improved Turnaround Scope) for facilitating risk based work selection.
The TA/RBWS assessments covered Work List items included in the refinery’s Turnaround Plans. The RBWS incorporated Becht’s Risk Based Benefit Cost Analysis (RBBCA) for equipment items that have a high financial impact. Equipment in each Process Unit was assessed by the refinery teams for inclusion in the TA Work List or for elimination, or deferment to a future turnaround. The work was completed by a team of Senior Specialists from Becht Engineering Company that included Arcot Radhakrishnan, Eileen Chant, Phong Diep, Don Bagnoli and Jerry Horak. Over 50 refinery personnel including Operations Supervisors, Process Engineers, Complex Managers, Subject Matter Experts (SMEs), TA Planners, Reliability Engineers, Inspectors, and Technicians participated in these assessments.
Excellent participation by the teams throughout the phases of equipment data collection, initial screening and analysis, and front end planning as well as during the RBI and RBWS work processes contributed to the successful outcome of this work. In addition to providing a significant cost savings to the site, the RBI Work Process for Fixed Equipment allowed for the development of Equipment Reliability Plans (ERPs) for each of the 187 vessels covered by the assessment. The ERPs describe all pertinent inspection, maintenance, monitoring and surveillance tasks and adequately define the scope of work to sustain long term reliability. The Equipment Task Lists include work that has been justified for TAs and provide the basis for TA Work Lists on future Unit Turnarounds.
The recommended Industry Best Practice for maintaining the ERPs is to set up a work process which ensures that Inspection and Operations periodically review data on thickness, and corrosion rates, and determine whether the documented risk levels in the ERPs may need changes. The development of the Equipment Reliability Plans will now allow the Unit Teams, with oversight from the Reliability Group, to maintain and update the ERPs to reflect inspection data and operating history. This Best Practice will enable the site to plan ahead for future events, and contribute towards reliability excellence in the long term.