1 / 35

Fire Detection and Suppression

Fire Detection and Suppression. Chapter 1 Fire Extinguishing Agents and Portable Fire Extinguishers . Portable Fire Extinguishers. First line of defense against incipient fires of limited size For a portable extinguisher to be effective, the following requirements must be met:

johnathan
Download Presentation

Fire Detection and Suppression

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Fire Detection and Suppression Chapter 1 Fire Extinguishing Agents and Portable Fire Extinguishers

  2. Portable Fire Extinguishers • First line of defense against incipient fires of limited size • For a portable extinguisher to be effective, the following requirements must be met: • Extinguisher must be readily accessible. • Extinguisher must be in working order. • Extinguisher must be suitable for the hazard • Operator must know how to use extinguisher. Fire Extinguishing Agents and Portable Fire Extinguishers

  3. Classification of Fires by Burning Characteristics • Class A: ordinary combustibles • Class B: flammable and combustible liquids and gases • Class C: energized electrical equipment • Class D: combustible metals • Class K: cooking devices that contain or use combustible vegetable or animal oils and fats Fire Extinguishing Agents and Portable Fire Extinguishers

  4. Extinguisher Symbols • Pictorial system (Fig. 1.2) • Letter system (Table 1.1) Fire Extinguishing Agents and Portable Fire Extinguishers

  5. How Extinguishers Are Rated • UL 711, Standard For Rating and Fire Testing Fire Extinguishers • Rating criteria • Intended use (fire class) • Fire fighting capability • Volume and duration of agent discharge • Range of discharge • Hydrostatic testing of the agent vessel and discharge hose Fire Extinguishing Agents and Portable Fire Extinguishers

  6. Extinguisher Rating Tests • Class A • Wood crib test • Wood panel test • Excelsior test • Class B: 2-inch (50 mm) layer of flammable liquid • Class C: nonconductivity (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  7. Extinguisher Rating Tests (cont.) • Class D: tested for specific types of metals • Magnesium fire tests • Sodium And Potassium Fire Tests • Class K: UL Standard 300 Fire Extinguishing Agents and Portable Fire Extinguishers

  8. Extinguishing Agents • Water • Antifreeze agents • Alkaline mixtures • Carbon dioxide (CO2) • Aqueous film forming foam (AFFF) • Film forming fluoroprotein (FFFP) (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  9. Extinguishing Agents (cont.) • Halogenated agents • Halotron and other replacement agents • Dry chemical agents • Ordinary • Sodium bicarbonate • Potassium bicarbonate • Multipurpose: monoammonium phosphate • Class D dry powders: NA-X; Met-L-X; Lith-X Fire Extinguishing Agents and Portable Fire Extinguishers

  10. Types of Fire Extinguishers • Stored-pressure • Cartridge-operated • Pump-operated • Obsolete types • Inverting • Soldered or riveted shell • Loaded stream Fire Extinguishing Agents and Portable Fire Extinguishers

  11. Selection and Distribution of Extinguishers (cont.) • General considerations • Nature of the hazard • Size of the extinguisher • Light hazard occupancy • Ordinary hazard occupancy • Extra hazard occupancy (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  12. Selection and Distribution of Extinguishers (cont.) • Specific considerations • Chemical and physical characteristics of combustibles • Potential severity of fire • Location of extinguisher • Effectiveness of the extinguisher for the hazard • Personnel available to operate the extinguisher • Environmental conditions (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  13. Selection and Distribution of Extinguishers • Specific considerations (cont.) • Anticipated adverse chemical reactions between the extinguishing agent and the burning material • Any health and occupational safety concerns • Inspection and service required (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  14. Selection and Distribution of Extinguishers (cont.) • Class A extinguisher distribution factors; substitutions in ordinary- and low-hazard occupancies • Class B extinguisher distribution factors • Distance to hazard • Depth of hazard • Flammable liquid fires without depth • Flammable liquid fires with depth (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  15. Selection and Distribution of Extinguishers (cont.) • Class C extinguisher distribution factors : • No special rules • Usually involve Class A or Class B fuels • Class D extinguisher distribution factors : • Requires analysis of specific metal present • Travel distance should not exceed 75 feet (25 m) (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  16. Selection and Distribution of Extinguishers (cont.) • Class K extinguisher distribution factors • Employee responsibilities • Travel distance should not exceed 30 feet (10 m) Fire Extinguishing Agents and Portable Fire Extinguishers

  17. Installation and Placement of Extinguishers • General guidelines • Visible and well signed • Not blocked by storage or equipment • Near points of egress or ingress • Near normal paths of travel (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  18. Installation and Placement of Extinguishers (cont.) • Installation guidelines • Height from floor • Temperature of environment • Snow, rain, corrosive fumes Fire Extinguishing Agents and Portable Fire Extinguishers

  19. Portable Fire Extinguishers on Fire Apparatus • General requirements: • Proper type for probable hazards • Accessible • Proper maintenance • NFPA 1901, Standard on Automotive Fire Apparatus (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  20. Inspecting, Maintaining, and Recharging Extinguishers • Infrequent use results in tendency to ignore extinguishers • Common problems • Misplaced or stolen extinguishers • Damage from being struck by vehicle • Lost pressure • Extinguishers used and replaced without notifying proper authorities (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  21. Inspecting, Maintaining, and Recharging Extinguishers (cont.) • Inspection: visual check to determine that an extinguisher is available and operable • Maintenance: thorough examination and performance of any needed service Fire Extinguishing Agents and Portable Fire Extinguishers

  22. Inspecting Extinguishers • Check that the extinguisher is in its proper location. • Ensure that access to the extinguisher is not obstructed by boxes, clothing, storage items, or is otherwise inaccessible. • Check the inspection tag to determine if maintenance is due. (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  23. Inspecting Extinguishers (cont.) • Examine the nozzle or horn for obstructions. • Check lock pins or tamper seals to make sure that they are intact. • Check for signs of physical damage. • Check that the extinguisher is full of agent. • Check that the pressure gauge indicates proper reading. (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  24. Inspecting Extinguishers (cont.) • Check collar tag for current information and/or damage. • Check that required signage is in place. • Check to see if the operating instructions on the extinguisher nameplate are legible. • Check that the extinguisher is suitable for the hazard protected. Fire Extinguishing Agents and Portable Fire Extinguishers

  25. Maintaining Extinguishers • Mechanical parts • Extinguishing agent • Expelling means Fire Extinguishing Agents and Portable Fire Extinguishers

  26. Recharging Extinguishers • Importance of following correct schedule • Using proper extinguishing agent • Pressurizing • Moisture contamination in nonwater extinguishers • Qualifications and training Fire Extinguishing Agents and Portable Fire Extinguishers

  27. Hydrostatic Testing of Portable Extinguishers • Failure of pressure vessels • Hydrostatic test: filling the cylinder with water and then applying appropriate pressure by means of a pump • Determining appropriate pressure • Signs that preclude testing an extinguisher • Record keeping Fire Extinguishing Agents and Portable Fire Extinguishers

  28. Using Portable Extinguishers Step 1: Activate alarm system. First, call appropriate fire department. Second, initiate local alarm. Step 2: Select a suitable extinguisher. Match extinguisher to fire. Analyze the type of hazard being protected and provide, in a conspicuous location, an extinguisher of the proper size and type. (Continued Fire Extinguishing Agents and Portable Fire Extinguishers

  29. Using Portable Extinguishers Step 3: Activate the extinguisher effectively. Stored pressure: remove safety pin and squeeze valve handle. Cartridge: remove nozzle from holder and depress lever that punctures cartridge seal. Step 4: Apply the extinguishing agent properly. (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  30. Using Portable Extinguishers (cont.) • P.A.S.S. Method • Pull the pin • Aim • Squeeze • Sweep (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  31. Using Portable Extinguishers (cont.) • Attacking Class A fires • Water-based extinguisher • Aim stream at seat of fire • Initial distance = 10–30 feet (3 m to 10 m) • AFFF extinguisher: same method as water-based • Multipurpose dry chemical • Attack fire at base • Sweep nozzle from side to side • Coat all fuel surfaces (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  32. Using Portable Extinguishers (cont.) • Attacking Class B fires • Regular or multipurpose dry chemical extinguishers • Begin discharge at about 10 feet (3 m), sweeping leading edge of fire and moving forward. • Begin second attacks with second full extinguishers. • C02 extinguishers • Apply at close range, sweeping surface of burning liquid with overlapping strokes. • Continue discharge after initial extinguishment (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  33. Using Portable Extinguishers (cont.) • Attacking Class C fires • Dielectric or nonconductive agent • Carbon dioxide* • Water mist* • Halon • Dry chemical (involves substantial cleanup) *Best choices • De-energize equipment if possible (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  34. Using Portable Extinguishers (cont.) • Attacking Class D fires • Dry powder agents • Apply with extinguisher or shovel • Cover fuel with 2-inch layer • Avoid disturbing fuel • Limitations of individual agents (Continued) Fire Extinguishing Agents and Portable Fire Extinguishers

  35. Using Portable Extinguishers (cont.) • Attacking Class K fires • Class K fire extinguisher recommended • Class A:B:C or Class B:C extinguisher: reignition possible • Application • Begin from distance of 10 to 12 feet (3.5 – 4 m) • Hold application wand at edge of flames and coat surface of fuel with side-to-side sweep. • Continue to apply agent until the fire extinguisher is completely empty. Fire Extinguishing Agents and Portable Fire Extinguishers

More Related