Plant hazard analysis basics

Fault tree for overpressure example (Fig. VII/1.2.2-1). BPCS, basic plant control system C Valve, control valve E/E/PE, electrical/electronics/programmable electronics IPL, independent protection layer PHA, plant hazard analysis SIS, safety instrumentation system. 

Concept Analysis of the Technical Plant after Planning. Preliminary hazard analysis and system structure analysis are intended to facilitate safety evaluation of the planned installation from the basic concept. Comprehensiveness of observation depends on the danger level of the installation. After concluding this work, basic changes in the technical procedure frequently become necessary and must be incorporated into the planning. 

Definition of hazard, risk discussions on likelihood, consequence risk — register, matrix, ranking. Consequence ranking, preliminary hazard analysis tolerance point—ALARP refreshing on mathematics, fault tolerance, plant ageing, and basic functional safety fail safe operations in plants. 

At about the same time as Mr. Friedman made the above remark, the author of this book was putting the final touches to his book Process Hazards Analysis (the contents of which are now incorporated into Process Risk and Reliability Management), a basic premise which is that everyone wants process plants to be safe. Although the book was going to the printers at the time of the attacks, there was time to add the following words to the Preface on September 20, 2001. 

Benson and Ponton propose, based on this analysis, the concept of distributed manufacturing [139, 145], which will be referred to in detail in Volume 2 of this book series. Basically, they refer to small, transportable plants which are fed with reactants over the fence , hence using only non-hazardous, generally available materials by normal piping or standard transport. If an aggressive chemical is needed, it has to be made from environmentally friendly base materials as an intermediate on-site. Needless to say, effluents have to be completely harmless, plant operation has to be intrinsically safe, and the plant should be clean and quiet. 

The basic steps involved in an external flooding analysis are similar to those followed for internal flooding in the individual plant examination. However, the focus of attention is on areas, which due to their location and grading may be susceptible to external flood damage. This requires information on such items as dykes, surface grading, locations of structures and locations of equipment within the structures. It is expected that the generic envelope will bound site hazard parameters. 

Suggestion If a hazard study life cycle is used the instrumentation team involved in using ISA or lEC standards may need to assist or encourage the plant engineers to generate the hazard and risk analysis as an extension to the basic HAZOP study. 

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