FIRE AND EXPLOSION RESISTANT SYSTEMS

The petroleum and related industries deal with tremendous bulk quantities of flammable and combustible materials daily. These materials are handled at extremely high pressures and temperatures where explosive, corrosive and toxic properties may also be present. It is therefore imperative not to become complacent about their destructive natures and the required protective arrangements that must be instituted whenever they are handled. 

Fire and explosion resistant materials and barriers for critical equipment or personnel protection should always be considered whenever petroleum operations are involved. They prolong or preserve the integrity of a facility critical features to ensure a safe and orderly evacuation and protection of the plant is accomplished. 

Ideally most oil or gas incidents will be controlled by the process shut down systems (ESD, depressurization, drainage, etc.) and hopeful the fire protection systems (fireproofing, water deluge, etc ), will not be required. However these primary fire defense systems may not be able to control fire incidents if previous explosions have previously occurred. Before any consideration of fire suppression efforts, explosion effects must first be analyzed to determine the extent of protection necessary. Most major fire incidents associated with hydrocarbon process incidents are preceded by explosion incident. 

Explosions are the most destructive occurrence that can transpire at a hydrocarbon facility. Explosions may happen too quickly for conventional fire protection systems to be effective. Once an explosion occurs damage may result from several events  

Overpressure - the pressure developed between the expanding gas and it s surrounding atmosphere. 

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Simplify (simplification and error tolerance) Keep piping systems neat and visually easy to follow Design control panels that are easy to comprehend Design plants for easy and safe maintenance Pick equipment that requires less maintenance Pick equipment with low failure rates Add fire- and explosion-resistant barricades Separate systems and controls into blocks that are easy to comprehend and understand Label pipes for easy walking the line Label vessels and controls to enhance understanding... 

The following appendices provide references to standards, fire resistance nomenclature, electrical ratings, hydraulic data, and conversion factors commonly referred to while examining and designing fire and explosion protection systems for the process industry. 

Fire-extinguishing procedure fight fire from a safe and explosion-resistant location. Use water from a sprinkler system or fog nozzle to extinguish the fire and dilute the spill and to keep the containers cool. 

Criterion 3 - Fire protection. Structures, systems, and components important to safety shall be designed and located to minimize, consistent with other safety requirements, the probability and effect of fires and explosions. Noncombustible and heat resistant materials shall be used wherever practical throughout the unit, particularly in locations such as the containment and control room. Fire detection and fighting systems of appropriate capacity and capability shall be provided and designed to minimize the adverse effects of fires on structures, systems, and components important to safety. Firefighting systems shall be designed to assure that their rupture or inadvertent operation does not significantly impair the safety capability of these structures, systems, and components. 

Water from a sprinkler system may be used from an explosion-resistant location to fight fire and keep the containers cool. 

The materials of construction, from the cupboard to the fan, should be inorganic and resistant to attack by perchloric acid. For the cupboard itself suitable materials include stainless steel of types, 316 or 317, solid epoxy resin, and rigid PVC. Stainless steel has been popular for this application as it is easy to form, weld, and polish. It is, however, attacked by the acid, which causes discoloration of the metal surface and the formation of iron(III) perchlorate, which can be explosive. Ductwork, separate from other extract systems, is usually made from stainless steel or plastic materials. Fire regulations may preclude the use of plastic ductwork or require it to be sheathed in an outer casing of metal or GRP. The fan casing and impeller can both be made of plastic. 

The USS Essex and three other LHD-class amphibious assault ships utilize furnace cameras to observe flame patterns and identify potential problems in a boiler combustion monitoring system and also monitor a pushbutton igniter-control system. Previously, a sailor monitored the fires through a small porthole, and an engineer in a flame-resistant jacket lit the boilers with a torch. If unburned fuel was in the boiler, explosions could occur. 

The laboratory shall be equipped with a fume hood. The fume hood should meet any specific safety requirements mandated by the nature of the research program. A discussion of hood design parameters will be found in a later section, but for high hazard use the interior of the hood and the exhaust duct should be chosen for maximum resistance to the reagents used the blower should either be explosion-proof or, as a minimum, have non-sparking fan blades the hood should be equipped with a velocity sensor and alarm should the face velocity fall below a safe limit the interior hghts should be explosion-proof, and all electrical outlets and controls should be external to the unit. It may be desirable to equip the unit with an internal automatic fire suppression system. 

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