Algorithm for Calculating the Inspection Interval of a Process Pipeline using a Risk-Oriented Approach according to the API 581 Methodology

Abstract

The article is devoted to the actual problems of planning periodic inspections of the equipment. The main task of the inspection is to assess the actual and (or) predicted technical condition of the equipment by carrying out design, experimental (diagnostic), research and organizational actions. Inspection can be implemented based on of one of two approaches: regulated and risk-oriented. The methodology given in the API 581 standard is used as the basis for conducting inspections. According to this methodology, risk is defined as a combination of probability and consequences of failure. An example is given related to calculating the inspection interval of the object under study. According to its results, the target date for the next inspection of the facility is set 8 years after the start of its operation. The article compares inspection methods based on two different approaches. It is shown that a risk-oriented approach implies a more deep and detailed study of the objects using the advanced methods, including continuous ultrasound scanning, profile (digital) radiography, pulsed eddy current testing. It is indicated that the efficiency of inspection methods used in the risk-oriented approach is due to their choice, considering the mechanisms of degradation of the object and depending on the specific conditions of its operation. Based on the results of the conducted work, it was concluded that the methodology for calculating inspection intervals based on the API 581 standard is an effective tool to ensure the optimal level of risk. With the development of the methods for organizing production, the methods for ensuring its safety should also be improved. The fact is noted that the application of the methodology of the risk-oriented approach in the Russian Federation is currently complicated due to the lack of an appropriate regulatory framework and methodological support. The emphasis was made on the need to resolve this problem, which will invariably lead to an increase in the efficiency of industrial production, including by the reduction of the equipment downtime during the preparation and conduct of the inspection.