Protection systems fire control

Dow Fire and Explosion Index. The Dow Eire and Explosion Index (3) is a procedure usehil for determining the relative degree of hazard related to flammable and explosive materials. This Index form works essentially the same way as an income tax form. Penalties are provided for inventory, extended temperatures and pressures, reactivity, etc, and credits are appHed for fire protection systems, process control (qv), and material isolation. The complete procedure is capable of estimating a doUar amount for the maximum probable property damage and the business intermptionloss based on an empirical correlation provided with the Index. 

Fire protection systems achieve control of burning by limiting the size of afire by ... 

In the majority of applications in processing facilities handling flammable gases or liquids, or liquefied flammable gases, fixed water-based fire protection systems will control, but not extinguish, the fire. Foam-water sprinkler systems are an alternative to water sprinkler systems. Both water and foam-water sprinkler systems are discussed in Chapter 7. 

It provides protection for personnel and equipment. This protection can include fire and explosion walls, ventilation systems, fire control systems, and the ability to detect fire and gas. 

Make use of fire and high-pressure protection systems for controlling struck-by and fire hazards. 

These markings provide a general idea of the hazards of a material and the severity of these hazards as they relate to handling, fire protection, exposure, and control. This standard is not applicable to transportation or to use by the general public. It is also not applicable to chronic exposure. For a full description of this standard, refer to NFPA 704. The system identifies the hazards of a material in four principal categories health, flammability, reactivity, and unusual hazards such as reactivity with water. 

Critical Equipment Equipment, instrumentation, controls, or systems whose malfunction or failure would likely result in a catastrophic release of highly hazardous chemicals, or whose proper operation is required to mitigate the consequences of such release. (Examples are most safety systems, such as area LEL monitors, fire protection systems such as deluge or underground systems, and key operational equipment usually handling high pressures or large volumes.)... 

The Guidelines for Process Equipment Reliability Data with Data Tables covers a variety of components used in the chemical process industry, including electrical equipment, analyzers, instrumentation and controls, detectors, heat exchangers, piping systems, rotating equipment (pump, compressor, and fan), valves, and fire protection systems. 

The third line includes fixed fire protection systems (sprinklers, water sprays, or deluge systems, monitor guns, etc.), dikes, designed drainage systems, and other systems that control or iiiitigaic ha. ardous releases. 

A typical block layout for a diesel engine room is given in Figure 15.29, showing the necessary auxiliaries and local control panels. Not shown but also necessary are cranes and fire-protection systems. 

These systems must be inherently reliable and safe, particularly from the point of view of fire protection, and fire-resistant fluids can be used for control systems in order to reduce this risk. Fire-detection and fire-fighting systems should always be provided for any turbogenerator installation. 

Industrial fire protection and safety engineers attempt to eliminate hazards at their source or to reduce their intensity with protective systems. Hazard elimination may typically require the use of alternative and less toxic materials, changes in the process, spacing or guarding, improved ventilation or, spill control or inventory reduction measures, fire and explosion protective measures - both active and passive mechanisms, protective clothing, etc. The level or protection is dependent on the risk prevalent at the facility versus the cost to implement safety measures. 

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. 

Fire Protection—The science of reducing loss of life and property from fire by control and extinguishment. Fire protection includes fire prevention, detection of a fire, providing systems to control or mitigate the fire, and providing manual firefighting capabilities. 

An active fire protection system requires some action to occur before it functions per its design intent. This action may be taken by either a person or control system. Examples of active fire protection systems are monitors, water spray systems, foam systems, emergency isolation valves, and ESD systems. 

Detection and Control The limitation of the severity of incidents by early detection of the incident and the operation of safety systems, including fire protection systems through fire and gas detection and process isolation. 

Defining the active protection systems needed to limit/control fire spread. 

The competence of personnel who select, design, install, test, and maintain fire protection systems is ultimately the factor that controls the effectiveness and reliability of fire protection systems. Many of the personnel described in the following sections are subject to jurisdictional requirements for licensing. 

Other supervisory signals may come from fire protection system components such as supervised control valves, system air and supervisory air pressure transmitters, water tank level and temperature transmitters, valve house and fire water pump building temperature transmitters, and fire water pumps. 

A water mist system is a proprietary fire protection system using very fine water sprays. The very small water droplets allow the water mist to control or extinguish fires by cooling of the flame and fire plume, oxygen displacement by water vapor, and radiant heat attenuation. These systems are single shot systems. A water mist system and nozzles are shown in Figure 7-28. 

Open grating floors allow spilled liquids or solids to fall through onto lower levels, possibly resulting in housekeeping problems and personnel exposure to spilled materials. In addition, if cascading liquid is ignited, a three-dimensional fire can result. These three-dimensional fires can be difficult to control by manual firefighting or even with fixed fire protection system. 

Since control rooms are normally constantly manned, it is considered unlikely that a fire could progress undetected to a hazardous size. Fixed fire protection systems, whether manually or automatically activated, are seldom installed in control rooms of processing facilities, mainly due to the fact that they are normally constantly manned. As such, it is considered unlikely that any fire that does occur would progress undetected to a size that cannot be extinguished by manual intervention (fire extinguishers, hose reel, etc.). 

Fire protection system impairment occurs when a fire alarm or supervisory system is shut-off, damaged, fails, or is otherwise taken out-of-service completely or in part. These out-of-service conditions are called impairments. While process monitoring, control, safety, and security-entry systems also provide protective functions, this element of the fire prevention program is only concerned with impairments to fire protection systems and equipment. An essential element of the fire prevention program is a procedure for fire protection impairment handling. 

Fire Protection System System Design System Pressure System Control Valve Locations ... 

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