Hazard evaluation logic diagram

Three hazard evaluation procedures using logic diagrams are (1) fault-tree analysis (FTA), (2) event-tree analysis (ETA), and (3) cause-consequence analysis (CCA). Appropriate references are [2,3,251,261]. 

Hazard analysis techniques Methods used to identify and evaluate hazards. These techniques cover the complete spectrum from qualitative preliminary hazard studies to system logic diagrams containing quantitative probabilities of mishap (APR 800-16). 

It is important to note that all the actions required by the trip logic diagram have been evaluated through hazard studies as being essential for the safety of personnel and plant. Hence the entire system shown is a safety system and remains independent of the basic process control system for the plant. The trip system plays no role in the start up of the plant except that it will prevent the start up of any one stage if it is not safe to do so by... 

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