| Risk-based inspection and maintenance is an advanced technology that can be used for equipment maintenance and inspection. Inspection plans and maintenance strategies are developed on the basis of quantitative risk calculation values, risk levels and risk target. The coverage of equipments maintained is improved by the rotation of inspection and maintenance resources. In this way, inspection and maintenance resources can be optimized, and minimum risks but maximum benefits be achieved.Started from the API581standard, its own flaws and limitations in the quantitative risk calculation of pressure vessels were studied deeply, and then the solutions to these problems were put forward by comparing the field data and results. Finally, the computational accuracy of risk and the scientific of inspection plans and maintenance strategies were improved in a large amount.The main research results obtained in this article were as follows:1. The failure data sample collected table for pressure vessels in different industries was designed, and the establishment of generic failure frequency database based on the Weibull function and the nominal area of pressure vessels was proposed;2. The damage factors were calculated according to the reliability theory and the failure probability formula based on the damage factor, nominal area and new generic failure frequency database was proposed;3. The calculation method of mole fraction weighted for multi-media release consequences of failure was present, and calculation results were compared with the recommended method of API581;4. For the situation of extended service and operating with defects, adjustment factors based on remaining life and defects were introduced to calculate quantitative risks, risk calculation and adjustment method for high pressure vessels were raised;5. Inspection plans, maintenance strategies and replacement cycle were developed based on the risks of pressure vessels. |
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