Equipment safety fire/explosion

Process Safety A discipline that focuses on the prevention and mitigation of fires, explosions, and accidental chemical releases at process facilities. Excludes classic worker health and safety issues involving working surfaces, ladders, protective equipment, etc. 

To develop a safe design, it is necessary to first design and specify all equipment and systems in accordance with applicable codes and standards. Once the system is designed, a process safety shutdown system is specified to assure that potential hazards that can be detected by measuring process upsets are detected, and that appropriate safety actions (normally an automatic shutdown) are initiated. A hazards analysis is then normally undertaken to identify and mitigate potential hazards that could lead to fire, explosion, pollution, or injury to personnel and that cannot be detected as process upsets. Finally, a system of safety management is implemented to assure the system is operated and maintained in a safe manner by personnel who have received adequate training. 

The first step in minimizing accidents in a chemical phuit is to evaluate the facility for potential fires, explosions, and vulnerability to other liazards, particularly those of a chemical miture. This calls for a detailed study of plant site and layout, materials, processes, operations, equipment, and training, plus an effective loss prevention program. The technical nature of industry requires detailed data and a broad range of experience. Tliis complex task, today becoming the most important in plant design, is facilitated by the safety codes, standiu ds, and practice information available. The technical approach to evaluating die consequences of hazards is discussed later in tliis cliapter and in Part V (Chapters 20 and 21). 

The rapid growth and expansion of the chemical industry has been accompanied by a spontaneous rise in human, material, and property losses because of fires, explosions, hazardous and toxic spills, equipment failures, other accidents, and business interruptions. Concern over the potential consequences of catastrophic accidents, particularly at chemical and petrochemical plants, has sparked interest at both the industrial and regulatory levels in obtaining a better understanding of the subject of this book Health, Safety, and Accident Management (HS AM). The writing of this book was undertaken, in part, as a result of this growing concern. 

A frequently used safety index in process industry is for instance the Dow Fire Explosion Hazard Index (1987). The Dow F E Index gives penalties for fired equipment and certain specified rotating equipment. These are a part of the Special Process Hazards, within which the penalties of a process unit are summed. 

In the aftermath of the Bhopal disaster, OSHA s Process Safety Management (PSM) has come into play and dictates the procedures to minimize the possibility of fire, explosion, or chemical release. If a project contains a regulated hazardous chemical, a process hazards analysis must be conducted to ensure that the likelihood of a fire, explosion, or release of hazardous chemicals is minimized and that equipment and facilities are included to minimize the effects of a fire, explosion, or release, if one does occur. 

Rational plant design is concerned with safety factors and with the need for minimizing such building and equipment hazards as corrosion, fire, explosion, and personal hazards from fume and poison. Process leaks and spillage hazards, hazards due to poor lighting, and reduction of... 

The engineering factor relates to the plant layout, its location, the equipment used, and its engineering standards. Special attention should be paid to the design stage at which safety and reliability rely upon the application of various codes of practice and standards. This is a basis for prevention of the fire explosions hazards. Within this factor, the philosophy of safety is based on the acceptance of the possibility of fire and explosion and provision of a method for protecting personnel and equipment from its consequences (protection method). 

Process safety risks Detailed study/verification is required to avoid overlooking safety risks to existing equipment/facilities. There may be more fire/explosion/toxic chemicals exposure risks during project execution as the revamp work may be executed in close proximity to existing facilities, handling flammable and toxic substances Process safety risk is relatively lower as all the equipment/ facilities are designed and installed at about the same time... 

Fires, explosions and toxic releases may have impacts inside the plant. For example, they may alfect installations adjacent to their place of origin and thus lead to the so-called Domino elfect. Since their intensity diminishes with distance (e.g. inversely proportional or inversely proportional to the square), distances between equipments make sense from the safety standpoint. On the other hand, they produce costs because of increased space requirements and higher energy consumption for the transport of materials. 

The ICI-MOND Fire Explosion and Toxicity Index (ICI 1985) was derived from DOW one and it is yet appreciated in process industry in many countries, including Italy. In ICI-MOND index method there are some ninety elementary questions, nested in a three levels tree. For many issues there is also a forth level of nested questions. About two thirds of the questions are for penalties and one third for credits accounting. For the most of the questions a quantitative answer is required. The questions are organized in chapters for penalties section the subjects are related to materials and quantities, processes and equipment, layout, health for credits section instead the method deals with containment, control, safety culture, fire engineering and emergency preparedness. Every issue weighs differently in overall risk levels accounting. Results are presented in a structured way, discriminat-iug fire, toxic, confined and unconfined explosion. 

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