This chapter discusses fire protection systems and equipment. It describes water supply systems including public and private water companies. It also discusses distribution systems, fire hydrants, and auxiliary water sources. The chapter describes fire detection systems and components. It discusses different types of extinguishing systems, agents such as water, foam, dry chemical, and gases. It also covers sprinkler systems, standpipes, and fire pumps.

1. Introduction to Fire Protection 3rd Edition

2. Chapter 12 Fire Protection Systems and Equipment

3. Objectives Describe the components of a water supply system Explain the importance of a dependable water supply system Describe the components and importance of a fire department water supply program Describe fire detection systems and their components

4. Objectives (con’t.) Describe different types of extinguishing systems and their components Describe the different types of extinguishing agents Explain how the various types of extinguishment agents work

5. Introduction Water is most common extinguishing agent Over the years, water systems have been become dependable and readily available Additives are added to water to increase effectiveness Other extinguishing agents have been developed for cases in which water causes damage or is ineffective

6. Public Water Companies Water is one of the single most important factor in municipal fire protection Water companies formed to provide adequate water supplies Fire or building department determines required fire flow for structures Water company may have to boost pressure to provide for flow at large fires

7. Private Water Companies Usually established to address industrial or commercial needs Maintain own distribution and storage Should be checked periodically by fire department

8. Water Supply Systems Storage capacity and redundancy of system Factors for determining required system capacity Frequency and duration of drought Danger to system from natural disaster

9. Water Supply Systems (con’t.) Types of supply systems Gravity fed systems Direct pumping systems Underground storage systems Combination systems Requires duplication of equipment to prevent shutdowns

10. Water Supply Systems (con’t.) Adequacy criteria Average daily consumption Maximum daily consumption Peak hourly consumption Minimum recognized water supply system for fire protection 250 gpm for 2 hours (30,000 gallons)

11. Distribution System From storage to treatment to consumer Water mains Underground piping of differing sizes Largest are called primary feeders Widely spaced throughout system Best when laid in grid pattern Looped to prevent dead ends and pressure drops

12. Distribution System (con’t.) Secondary feeders Reinforce grid Concentrate supply in high demand areas Distributors Serve individual hydrants and blocks of consumers

13. Fire Hydrants Two basic types (see Figure 12-5) Wet barrel Contains water May have more than one valve Common fitting sizes: 2 ½, 4, and 4 ½ inch Dry barrel Is dry to prevent freezing Valve located underground

14. Fire Hydrants (con’t.) Special hydrant types Airport taxiway/runway Totally underground Dry hydrant Drafting source from static water supply Facilitates drafting operations Hydrant spacing is specified by local ordinance

15. Fire Hydrants (con’t.) Hydrant maintenance program Inspect, clean, and lubricate all parts Clear weeds and other obstructions Flush when necessary Notify water company first Open and close valves slowly Water hammer may occur if valves are closed too quickly, especially at high flows or pressures

16. Fire Hydrants (con’t.) Hydrant testing Performed on new systems to assess flow rates Performed on old systems to assess condition of system Hydrant painting Painted for visibility Color coded to identify flow rates (developed by NFPA)

17. Water Systems Program Used to promote cooperation between fire department and water companies Letter of working agreement Water system map Hydrant records Maintaining water system familiarizes personnel with the location of hydrants

18. Auxiliary Sources of Water Supply In areas with lack of an adequate water supply system, especially rural areas Water available from static sources Cisterns, reservoirs Canals, creeks, rivers Tanks, swimming pools, etc. Preplan your area and identify sources

19. Private Fire Protection Systems Designed to protect individual properties from fire Uses detection devices Has two main purposes Alert building occupants Notify fire department

20. Detection Devices Smoke detectors For public education purposes, the NFPA prefers the term “smoke alarm” A working smoke alarm in the home doubles a person’s chances of surviving a fire Change your clock Change your battery Test your alarm monthly

21. Detection Devices (con’t.) Smoke/flame detector types Ionization chamber Flame or light detector Visible smoke detector Rate of rise detector Fixed temperature detector

22. Detection Devices (con’t.) Alarm system activation Manual pull stations (see Figure 12-14) Water flow switch or excess flow switch Many systems have combinations of smoke/heat detectors and other devices

23. Extinguishing Agents Water Most commonly used agent High specific heat One gallon absorbs 1,280 BTU when temperature raised from 62 degrees to 212 degrees Additional 8,080 BTU absorbed when going from 212 degrees water to 212 degrees steam Volume expands 1,700 times when converted to steam

24. Extinguishing Agents (con’t.) Foam Consists of concentrate added to water Extinguishes three ways Cools surface Cuts off vapor production Insulates surface from radiated heat

25. Extinguishing Agents (con’t.) Types of foam Chemical Combination of two agents Chemical reaction creates bubbles Mechanical Concentrate added to hose stream through inductor Nozzle adds air to create bubbles

26. Extinguishing Agents (con’t.) Types of mechanical foam (Class B) AFFF AFFF ATC Protein Fluorinated protein High expansion

27. Extinguishing Agents (con’t.) Class A foam When used with CAFS, will stick to vertical surfaces to form fire resistive protection layer Acts as wetting agent Reduces surface tension of water Helps it soak into fuel/reduces runoff Do not mix foam types Use the right type for the classification of fire

28. Extinguishing Agents (con’t.) Wetting agents Reduce surface tension of water and allow it to soak into fuel at faster rate Water does not evaporate as fast Less water is needed for job Deep seated embers are extinguished more quickly

29. Extinguishing Agents (con’t.) Fire retardant Short term Depends on wetness to suppress fire Uses class A foam and wetting agents Applied by air or ground-based units Long term Depends on chemical reaction with fuel Contains pigment to remain visible from air Applied by aircraft

30. Extinguishing Agents (con’t.) Other agents Carbon dioxide (CO 2 ) dilutes oxygen to smother fire Halogenated agents break chemical chain reaction Clean agents act like halogenated agents and do not damage ozone layer

31. Extinguishing Agents (con’t.) Other agents (con’t.) Dry chemical Breaks chemical chain reaction Used for A, B, and C fires Can be used along with water Must be followed up with water to ensure deep-seated embers are extinguished

32. Extinguishing Agents (con’t.) Other agents (con’t.) Dry powder Used for class D fires Used on flammable metals May just be dry sand in a pail Safety Note : Water may react violently with some combustible metals, causing an explosion of hot metal particles

33. Extinguishing Systems Automatic sprinklers Proven 96% effective Failures are primarily due to Improper maintenance Inadequate or shut off water supply Incorrect installation or design Obstructions

34. Residential Sprinklers Less expensive than commercial systems Less complicated Proven effective, but not commonly installed due to: Added cost Misconception that operation results in water damage

35. Commercial and Industrial Sprinkler Systems Basic components Fire department connection Open screw and yoke (OS&Y) valves Post indicator (PI) valves Backflow prevention Main control valve

36. Wet Pipe System Used where freezing is not a concern Water remains behind sprinkler heads at all time Clapper in control valve keeps water pressure constant in system Alarm valve actuates when flow is detected Retard chamber prevents false alarms due to pressure fluctuations

37. Dry Pipe System Used where freezing is a concern Compressed air in system keeps water below clapper in main control valve Head opening releases air pressure and water enters system System may cause delay in water discharge at head

38. Dry Pipe System (con’t.) Fire department connection Attached to riser For boosting system pressure with fire department apparatus May be several in high rise or other large structures Know which ones to connect to Preplan your systems and mark if possible

39. Dry Pipe System (con’t.) Path of water through system Water main PI valve and OS&Y (may have back flow preventer) Through main valve mounted on riser Feed mains Cross mains Branch lines Sprinkler heads

40. Dry Pipe System (con’t.) Deluge system All sprinkler heads open at all times Sensor system releases water into sprinkler system Used where flooding amounts of water are required Systems are used in LPG storage, lumber operations, etc.

41. Dry Pipe System (con’t.) Preaction system Closed sprinkler heads Preaction valve opens on activation Allows water into piping Water is discharged when heat is sufficient to open sprinkler head

42. Sprinkler Heads Include deflector to divide flow into droplets Various types for differing applications Pendant: head down Upright: head upright Sidewall: head horizontal Note : Types are not interchangeable and should only be used as designed

43. Standpipe Systems Usually found in stairwells Prevent having to lay hose to upper floors Class I: 2 ½ inch hose connection for Fire Department use Class II: 1 ½ inch hose connection with hose for occupant use Class III: 2 ½ and 1 ½ inch connection for occupant and fire department use Watch out for pressure-reducing devices

44. Foam Systems Can create foam in several ways Eduction: draws concentrate into hose stream through Venturi action Injection: injects concentrate into system before or after main pump Batch mixing: pours concentrate into tank Premixing: concentrate and water stored as mixture

45. Gas Extinguishing Systems Used when water will cause excessive damage to stock or electrical installations Carbon dioxide Stored in large tanks/cylinders Plumbed to nozzles Alarm evacuates area before discharge Release delayed to allow evacuation

46. Dry Chemical Systems Powder stored in a container Common fire extinguisher May have expellant gas in container with powder or in remote reservoir Can handle rough service Requires little maintenance

47. Wet Chemical Extinguishing Systems Used for combustible cooking Installed hood system or portable extinguishers Reduces temperature of liquid and applies extinguishing agent

48. Fire Extinguishers From very small to very large Found in all types of applications Different types for all classifications of fires Not for use on all classifications of fire at the same time Check the label before using

49. Obsolete Agents Some obsolete extinguishers are still in use Soda acid, carbon tetrachloride If encountered Remove these from service Handle carefully ad dispose properly If unsure of extinguisher type, ask local extinguishing service to assist

50. Fire Pumps Boosts pressure in fixed systems Diesel and/or electric powered System may have both Centrifugal pumps Vertical turbine pumps

51. Pressure-Reducing Devices Used to reduce pressure on lower floors of high-rise buildings Used to reduce pressure in standpipe systems May require special nozzles to provide effective firefighting hose stream Preplan the location and types of systems for safety

52. Fire department should maintain close relationship with local water company Firefighters must: Be familiar all types of extinguishing agents Be aware of the hazards of agents Know how to operate all agent systems Stay informed of new agents and systems Be able to pick the best option available at an incident Summary