Fire Suppression Systems

Check for plant integrity/flammable leaks periodically or continuously on-line, as appropriate Install appropriate fire/smoke detection, audible alarms Provide adequate fire suppression systems Deal with mishaps such as spillage immediately... 

Ensure the adequaey (in terms of quality, quantity and reliability) of serviees/utilities, e.g. steam, proeess/eooling water, eleetrieity, eompressed air, inert gas, fire suppression systems, ventilation. Stand-by or emergeney serviees may be required. Some general safety design eonsiderations are summarized in Table 12.11. 

The unique combination of properties associated with certain fluonnated methanes and ethanes has led to their widespread use in fire suppression systems The three halogenated fire suppression agents in general use today are bromo-trifluoromethane (CF Br, Halon 1301), bromochlorodifluoromethane (CF2BtCl, Halon 1211) and, in small volumes, primarily in the republics of the former Soviet Union and Eastern European nations, 1,2-dibromotetrafluoroethane (BrCF2Cp2Br, Halon 2402)... 

Taxonomy No. 4,2.3.2 Equipment Description PROTECTION SYSTEMS-FIRE- FIRE SUPPRESSION SYSTEMS-WATER ... 

Direct damage to assets This may be caused by explosion, rainwater ingress and fire. The level of security is dependent upon good building details and the fire-suppression system used. 

In some cases more drastic action may be necessary. For instance, when the temperature of a reactor exceeds a given value a reaction inhibitor may be added to the mixture. Or, as noted before, when small solid particles are being handled in the presence of air, a fire-suppression system may be installed that will quickly snuff out any incipient explosion. 

The data reported in Table VI for Halon 1301 concentration required for flame extinguishment vary in the range of 3 to %, which is comparable to the range found for ordinary combustibles. Thus maintenance of Halon 1301 concentrations in excess of is expected to extinguish fires in the ignition zone for the FRC materials this concentration limit satisfies the current Halon 1301 requirements for fire suppression systems for tracked vehicles. 

Advancements In Electronic Fire Detection in the past fifteen to twenty (15 to 20) years has made Ultra High Speed Deluge Systems for explosive facilities quite feasible and reliable. Since Detection has been covered in previous chapters, this chapter will focus mainly on Ultra High Speed Deluge Fire Suppression. Discussed are the three (3) most popular ultra high speed fire suppression systems presently used in explosive facilities. 

Facility Emergency Response Measures (e.g., Fixed fire suppression systems, fire fighting, first aid, etc.). From 0-4 hours after incident Severe... 

Release of flammable vapors from piping due to inadequate isolation/maintenance. Explosion impacted fire suppression system. 

Improper operating procedure cause a chemical process upset resulting in a tank boilover and vapor release. Explosion impacted fire suppression system capability. 

Release of combustible chemical vapors to atmosphere during process upset. Explosion impacted capability of the fire suppression system. 

Lightning struck storage tank, cause explosion and fire which spread to other tanks. Fire suppression system impacted during explosion losing its capability. 

The first task in applying a spacing table to a facility is to ensure it corresponds to the philosophy of protection adopted by the company. Where limited space is available to provide the required spacing, an examination of the equivalent fire and explosive barriers or active fire suppression system should be confirmed. This analysis should be accepted by the company as part of the design risk analysis. 

Alarms should be initialed by the local or main control facility for the location. Manual activation means should be provided for all emergency, fire, and toxic vapor alarm signals. Activation of fire suppression systems by automatic means should also indicate a facility alarm. Most fire and gas detection systems are also set to automatically activate alarms after confirmation and set points have been reached. Manual activation of field or plant alarm stations should activate the process or facility alarms. 

The objectives of fire suppression systems are to provide cooling, control the fire (i.e., prevent it from spreading) and provide extinguishment of the fire incident. A variety of fire suppression methods are available to protect a facility. Both portable and fixed systems can be used. The effectiveness of all fire extinguishing measures can be determined by the rate of flow of the extinguishing agent and the method or arrangements of delivery. 

All fixed fire suppression system control valves should be located out of the fire hazard area but still within reach of manual activation. For high hazard areas (such as offshore facilities), dual feeds to fire suppression systems should be considered from opposite areas. For onshore facilities, firewater isolation valve handles should not be contained within a valve pit or a below grade enclosure within the vicinity of hydrocarbon process facilities, since heavy process vapors travel from the process and may settle inside. 

Hydrants should be considered as a backup water supply source to monitors and fixed fire suppression systems. Hydrants should be located on the ring main at intervals to suitably direct water on the fire hazard with a fire hose. Hydrants monitors and hose reels should be placed a minimum of 15 meters (50 ft.) from the hazard they protect for onshore facilities. Hydrants in process areas should be located so that any portion of a process unit can be reached from at least two opposite directions with the use of 76 meters (250 ft), hose lines if the approach is made from the upwind side of the fire. Offshore hydrants are located at the main accessways at the edge of the platform for each module. Normal access into a location should not be impeded by the placement of monitors or hydrants. This is especially important for heavy crane access during maintenance and turnaround activities. 

Leakages from CO2 fire suppression systems are considered extremely rare. With adequate inspection and maintenance procedures a leak on the system should generally not be expected to occur. Installed pressure gages on the CO2 cylinders should be frequently checked against the initial pressure readings. If they are found to be different, immediate action should be taken to investigate possible leakages. 

Depending on the criticality and value additional fire suppression systems are provided for protection. NFPA 850 section 5-8.6 recommends that oil-filled station and start-up transformers at power generation plants be protected with a water or foamwater spray system. The most common installation is a fixed water spray. Where several transformers are provided, a firewall is commonly used to separate and protect one unit from another. 

Additional resources include the National Fire Protection Association (NFPA), the Society for Fire Protection Engineers (SFPE), Fire Suppression Systems Association (FSSA), and the American Petroleum Institute (API). Refer to the References section of this Guideline for specific resources. 

Many states now require lire suppression systems for public service stations and for some private fleet refueling facilities. Most of these systems are dry chemical using infrared detectors and work as effectively on methanol vehicle fires as gasoline vehicle fires. No special requirements are necessary for these systems when used at a methanol refueling facility. All fire suppression systems should be checked after installation for proper coverage using a fraction of the dry chemical that would normally be used (this is called a puff test ). The puff test not only shows the coverage that will be obtained, but tests the components of the fire protection system. 

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