Gaseous Agent Extinguishing Systems  Chapter 10
Learning Objectives <ul><li>Describe the physical characteristics of carbon dioxide </li></ul><ul><li>Describe the four ap...
Learning Objectives (continued) <ul><li>Explain the halon numbering identification system </li></ul><ul><li>Describe the p...
Introduction <ul><li>Alternative fuels were developed to cope with new manufactured materials </li></ul><ul><li>Environmen...
Carbon Dioxide <ul><li>Odorless, colorless, noncombustible, and nonconductive </li></ul><ul><li>Exists in air at a very sm...
Carbon Dioxide Fire Extinguishing Systems <ul><li>Self-contained and use fixed nozzles, manual hose reels, or both </li></...
Low- and High-Pressure Storage <ul><li>Two types of carbon dioxide extinguishing systems: </li></ul><ul><ul><li>Low-pressu...
Figure 10-1 Low-pressure carbon dioxide extinguishing system protecting a chemical storage facility
Carbon Dioxide Delivery Systems <ul><li>Local application systems  protect a specific area </li></ul><ul><li>Total floodin...
Halogenated Agents <ul><li>Halogenated hydrocarbons : mixture of carbon and one or more halogen elements </li></ul><ul><ul...
Halon Fire Extinguishing Agents <ul><li>Odorless, colorless, non-corrosive, nonconductive, nontoxic at low concentrations ...
Halon Extinguishing Systems <ul><li>Pre-engineered or engineered, self-contained </li></ul><ul><li>To start sequence, auto...
Halon Delivery Systems <ul><li>Two types of halon delivery systems: </li></ul><ul><ul><li>Local application </li></ul></ul...
Figure 10-4 These storage tanks are a part of a total flooding halon extinguishing system
Location Application Systems <ul><li>Protect specific areas by discharging halon directly onto the hazard </li></ul><ul><l...
Total Flooding Systems <ul><li>Protect enclosed hazards by filling the entire enclosure with halon </li></ul><ul><li>Amoun...
Clean Agents <ul><li>Halocarbons  or  clean agents  are environmentally safe, non-toxic, not electrically conductive; leav...
Categories of Clean Agents <ul><li>Clean agents fall into  inert gas-based  category </li></ul><ul><li>Extinguish by inter...
Clean Agent Extinguishing Systems <ul><li>Only application method is total flooding </li></ul><ul><li>System activation op...
Approval and Periodic Inspection, Testing, and Maintenance <ul><li>All carbon dioxide, halon, clean agent systems must go ...
Carbon Dioxide <ul><li>Once installation complete, NFPA 12 requires visual, operational, discharge inspections and tests <...
Halon <ul><li>NFPA 12B, the standard for halon 1211, is obsolete </li></ul><ul><li>Ten-minute pneumatic pressure test dete...
Clean Agents <ul><li>Visual inspection verifies components are correctly placed, and all signage is in place </li></ul><ul...
Figure 10-8 A Test equipment used to determine the amount of air leakage from the enclosure
Summary <ul><li>Alternative extinguishing agents developed for new manufactured materials </li></ul><ul><li>Gaseous system...
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Chapter 10

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Chapter 10

  1. 1. Gaseous Agent Extinguishing Systems Chapter 10
  2. 2. Learning Objectives <ul><li>Describe the physical characteristics of carbon dioxide </li></ul><ul><li>Describe the four application methods of delivery for carbon dioxide </li></ul><ul><li>Explain the reason for and the impact of the Montreal Protocol </li></ul><ul><li>Describe the physical characteristics of halogenated hyrdrocarbons (halons) </li></ul>
  3. 3. Learning Objectives (continued) <ul><li>Explain the halon numbering identification system </li></ul><ul><li>Describe the physical characteristics of halocarbons and inert gases (clean agents) </li></ul><ul><li>Name the two categories of clean agents </li></ul>
  4. 4. Introduction <ul><li>Alternative fuels were developed to cope with new manufactured materials </li></ul><ul><li>Environment, logistics, technological application may make it impractical to use water </li></ul><ul><li>Necessary to prevent water damage to extremely valuable property </li></ul><ul><li>Extinguishing gases offer an alternative </li></ul><ul><li>Three types of gases: carbon dioxide, halons, and clean agents </li></ul>
  5. 5. Carbon Dioxide <ul><li>Odorless, colorless, noncombustible, and nonconductive </li></ul><ul><li>Exists in air at a very small level </li></ul><ul><ul><li>Approximately 380 parts per million by volume </li></ul></ul><ul><li>Displaces and reduces the level of oxygen below 15% of the air content </li></ul><ul><li>50% heavier than air, and separates air from the fuel as it extinguishes the fire </li></ul><ul><li>Not suitable for reactive metals, materials containing oxygen, metal hydrides </li></ul>
  6. 6. Carbon Dioxide Fire Extinguishing Systems <ul><li>Self-contained and use fixed nozzles, manual hose reels, or both </li></ul><ul><li>Highly pressurized CO 2 liquid expands to a gas vapor state, combines with moisture in the air </li></ul><ul><ul><li>Forms a fog-like cloud that consumes the hazard </li></ul></ul><ul><li>Cloud quickly dissipates, but gas lingers to maintain non-ignitable environment </li></ul><ul><li>Useful where clean up of another agent would be problematic </li></ul>
  7. 7. Low- and High-Pressure Storage <ul><li>Two types of carbon dioxide extinguishing systems: </li></ul><ul><ul><li>Low-pressure storage: stores about 300 psi </li></ul></ul><ul><ul><li>High-pressure storage: stores above 850 psi </li></ul></ul><ul><li>Both high enough to make CO 2 self-expel </li></ul><ul><li>Low-pressure systems require refrigeration/heating equipment </li></ul><ul><li>Activation may be automatic, manual, or emergency manual </li></ul>
  8. 8. Figure 10-1 Low-pressure carbon dioxide extinguishing system protecting a chemical storage facility
  9. 9. Carbon Dioxide Delivery Systems <ul><li>Local application systems protect a specific area </li></ul><ul><li>Total flooding systems protect enclosed hazards, rooms, and areas within a structure </li></ul><ul><ul><li>Fill entire enclosure with CO 2 </li></ul></ul><ul><li>Hand hose system are manual delivery </li></ul><ul><ul><li>Individual accesses a hose, real, and nozzle </li></ul></ul><ul><li>Standpipe/Mobile supply systems installed at industrial facilities </li></ul><ul><ul><li>For use by trained personnel </li></ul></ul>
  10. 10. Halogenated Agents <ul><li>Halogenated hydrocarbons : mixture of carbon and one or more halogen elements </li></ul><ul><ul><li>Also called halon </li></ul></ul><ul><li>Numbering system indicates chemical makeup </li></ul><ul><ul><li>Halon 1211 : 1 part carbon, 2 parts fluorine, 1 part chlorine, 1 part bromine </li></ul></ul><ul><ul><li>Halon 1301 : 1 part carbon, 3 parts fluorine, zero parts chlorine, 1 part bromine </li></ul></ul><ul><li>Halon 1211 and 1301 are only two halons in widespread use in fire systems </li></ul>
  11. 11. Halon Fire Extinguishing Agents <ul><li>Odorless, colorless, non-corrosive, nonconductive, nontoxic at low concentrations </li></ul><ul><ul><li>Leave minimal residue </li></ul></ul><ul><li>Halons break down the reaction sequence of fire </li></ul><ul><li>Effective on Class B and C fires </li></ul><ul><li>Protect computer rooms, electronic equipment, flammable and combustible liquids, etc. </li></ul><ul><li>Not suitable for reactive metals, materials containing oxygen, metal hydrides </li></ul>
  12. 12. Halon Extinguishing Systems <ul><li>Pre-engineered or engineered, self-contained </li></ul><ul><li>To start sequence, automatic detection, activation, and manual controls required </li></ul><ul><li>Emergency release by a single manual operation, appropriate warning devices required </li></ul><ul><li>Manual abort switch must be located within the hazard area </li></ul><ul><ul><li>Requires constant pressure to maintain abort status </li></ul></ul><ul><ul><li>Time delay allowable when people must evacuate </li></ul></ul>
  13. 13. Halon Delivery Systems <ul><li>Two types of halon delivery systems: </li></ul><ul><ul><li>Local application </li></ul></ul><ul><ul><li>Total flooding </li></ul></ul><ul><li>Same types of systems that protect CO 2 , wet, and dry chemical systems </li></ul><ul><li>Type of system installed determines the type of halon used </li></ul><ul><li>Most halon systems are total flooding type </li></ul>
  14. 14. Figure 10-4 These storage tanks are a part of a total flooding halon extinguishing system
  15. 15. Location Application Systems <ul><li>Protect specific areas by discharging halon directly onto the hazard </li></ul><ul><li>Appropriate when enclosing a hazard is not possible or practical </li></ul><ul><li>Nozzle placement and type critical to ensure appropriate application of the agent </li></ul><ul><li>Halon 1211 is a liquid stream agent; best for local application delivery </li></ul><ul><li>When discharged, agent expands as a mixture of liquid droplets and vapor </li></ul>
  16. 16. Total Flooding Systems <ul><li>Protect enclosed hazards by filling the entire enclosure with halon </li></ul><ul><li>Amount of halon and number of nozzles needed depend on total volume of the area </li></ul><ul><li>Concentration levels range from 4% to 15% by volume </li></ul><ul><li>Halon 1301 more appropriate for total flooding systems </li></ul><ul><li>Once discharged, uniform and rapid distribution </li></ul>
  17. 17. Clean Agents <ul><li>Halocarbons or clean agents are environmentally safe, non-toxic, not electrically conductive; leave no residue </li></ul><ul><li>Effective on Class A, B, and C fires </li></ul><ul><li>Protect computer rooms, telecommunication facilities, radio and television broadcast, etc. </li></ul><ul><li>Possibility of health problems if exposed for an extended time at high concentrations </li></ul><ul><li>Exposure during fire may subject a person to higher levels of byproducts than with halon </li></ul>
  18. 18. Categories of Clean Agents <ul><li>Clean agents fall into inert gas-based category </li></ul><ul><li>Extinguish by interrupting the chain reaction or removing the heat from the reaction zone </li></ul><ul><li>Inert agents reduce the oxygen level in protected area </li></ul><ul><li>Five subcategory designations: </li></ul><ul><ul><li>FC, FK, FIC, HFC, HCFC </li></ul></ul><ul><ul><li>Identify the chemical composition of the mixture </li></ul></ul><ul><li>Inert gases have designation IG </li></ul><ul><ul><li>Mixture of helium, neon, argon, nitrogen, CO 2 </li></ul></ul>
  19. 19. Clean Agent Extinguishing Systems <ul><li>Only application method is total flooding </li></ul><ul><li>System activation operates a discharge control head and valve </li></ul><ul><ul><li>Allows gas to escape the cylinders, flood the piping and flow to nozzles </li></ul></ul><ul><li>Substantial discharge of the agent: </li></ul><ul><ul><li>Within 10 seconds of activation for halocarbons </li></ul></ul><ul><ul><li>Within 60 seconds for inert agents </li></ul></ul>
  20. 20. Approval and Periodic Inspection, Testing, and Maintenance <ul><li>All carbon dioxide, halon, clean agent systems must go through periodic inspection, testing, and maintenance </li></ul>
  21. 21. Carbon Dioxide <ul><li>Once installation complete, NFPA 12 requires visual, operational, discharge inspections and tests </li></ul><ul><li>When system is operational, weekly and monthly visual inspections: </li></ul><ul><ul><li>Prevent conditions that prevent proper operation </li></ul></ul><ul><ul><li>Determine if there have been changes in the hazard </li></ul></ul><ul><ul><li>Determine if there is equipment damage or signs of system leaks </li></ul></ul><ul><li>Liquid level and pressure on low-pressure systems requires checking </li></ul>
  22. 22. Halon <ul><li>NFPA 12B, the standard for halon 1211, is obsolete </li></ul><ul><li>Ten-minute pneumatic pressure test determines if there is pipe leakage </li></ul><ul><li>Puff test ensures piping continuity </li></ul><ul><li>Enclosure integrity test determines amount of leakage from the enclosure </li></ul><ul><li>Concentration level should be at least 80% of design amount after 10 minutes </li></ul>
  23. 23. Clean Agents <ul><li>Visual inspection verifies components are correctly placed, and all signage is in place </li></ul><ul><li>Operational testing verifies mechanical and electrical components perform as required </li></ul><ul><li>Ten-minute pneumatic pressure test determines if there is pipe leakage </li></ul><ul><li>Puff test ensures piping continuity </li></ul><ul><li>Significant leakage will reduce the concentration to below an acceptable level </li></ul>
  24. 24. Figure 10-8 A Test equipment used to determine the amount of air leakage from the enclosure
  25. 25. Summary <ul><li>Alternative extinguishing agents developed for new manufactured materials </li></ul><ul><li>Gaseous systems are self-contained, engineered, or pre-engineered systems </li></ul><ul><li>Gases work well on Class A, B, and C type fires </li></ul><ul><ul><li>Not suitable for reactive metals, materials containing oxygen, metal hydrides </li></ul></ul><ul><li>Halons no longer manufactured for environmental reasons </li></ul><ul><ul><li>Clean agents work well as halon substitutes </li></ul></ul>

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