Research On The Method Of Quantitative Evaluation Of Pressure Vessel Risk API 581

Risk assessment is the potential risk of the equipment are analyzed to improve the effectiveness of the inspection apparatus, the risk assessment test method is also known as risk-based (RBI technology). RBI is a complete assessment of technical means, it first appeared on the device may damage mechanisms and failure modes assessed using qualitative or quantitative methods determine the likelihood of failure and the consequences of failure, come to the final equipment risks. Based on the risk level of risk and then sort of a single device or set of devices, according to the results of the risk ranking can be found in the device need to focus on the device or devices in key positions, so you can develop targeted maintenance programs, reduce costs, and to avoid accidents, so that safe and effective operation of the device.Currently the international petrochemical industry for risk assessment of pressure vessels used mainly API581standards, many of our petrochemical units also its sets of equipment were based on API581standard risk assessment. However, API581standard, there are some deficiencies in risk assessment, there are some non-adaptive pressure vessel industry in our country. Therefore, this paper API581standard for the study, and improved its quantitative assessment methods, so that it can adapt to China’s pressure vessel industry’s risk assessment.This article will risk assessment methods were compared with the traditional method of risk assessment methods advantages in the detailed interpretation of them pointed out the shortcomings of the method. Through factor correction model to analyze the generic failure frequency and impact of the correction factor is crucial failure possibilities. In view of the pressure vessel industry, designed the failure data sampling table, and use the Weibull distribution model and stress-strength model were derived formulas and equipment generic failure frequency correction coefficients. Finally, a representative of the media law and the molar volume weighted flash Flash principles model to calculate the rate of mixed-phase stream discharge and the consequences of failure consequence area, in order to improve the accuracy of the consequences of failure calculations. Finally, an example of proof, standard methods were used and improved methods to assess comparative examples, and analyzes the feasibility of the improved method.