HAZOP - hazard and operational analysis
Node division: according to different processes, the traditional division with main material as the core can be adopted in Europe, or the division with process unit as the core which is gradually popular in China in recent years. The node is a forced cutting of the process flow for the convenience of HAZOP analysis. While HAZOP analysis is convenient, there is no overall view in the analysis.
Deviation selection: the empirical method (i.e. the preference for the deviation close to the consequence) is combined with the traditional method (the preference for the deviation close to the cause). For continuous processes, 18 common deviations that must be analyzed and 24 common deviations that must be analyzed for intermittent operations were selected. All the leading words and parameters are meaningfully combined, and 124 deviations which may need to be analyzed are obtained as supplements, which not only guarantee the quality of analysis but also improve the efficiency, and at the same time guarantee the overall level of the analyst.
Cause search: summarize the causes of common deviations. In order to ensure the quality of analysis, formulate 8 principles of cause search. In principle 8, there is a guarantee that the initial cause (sometimes called the immediate cause) will be found, but there is also a guarantee that in some special cases intermediate events will be allowed as the cause, and that intermediate events will be reflected in the analysis.
Consequence search: in order to ensure the quality of the analysis, 9 principles of cause search are formulated. In principle 9, it is stipulated that the ultimate adverse consequences are found, and intermediate events are allowed to be used as consequences in some special cases. Also, in principle 9, it is stipulated when to analyze the consequences of protection measures after they are activated, such as safety valve take-off and interlock action.
Protection measures: in order to ensure the quality of analysis, the protection measures search 3 principles are formulated, the concept of independent protection layer (IPL) is introduced, and the administrative measures can be used as protection measures, and the alarm can be used as protection measures. Avoid protection measures only look at the number of quality problems.
Risk assessment: the method of protection layer analysis is used to estimate the frequency of accidents in accident scenarios, so as to provide a reference for the team to decide whether the risks are acceptable.
Suggested measures: the guarantee the quality of analysis, formulate measures for 4 principles, rules effective Suggestions and possible effective suggestion, the difference between a regulation when must use separate layer as a suggestion, also specifies when to take administrative measures as advice, to ensure that after the suggested measures to implement can reduce the risk to an acceptable level.