FIRE FIGHTING SYSTEM

1. FIRE FIGHTING SYSTEM • Fire is a reaction giving off heat, light, and smoke; • The three essential elements for a fire to occur are: heat, fuel, and oxygen. • These three elements form what is called the fire triangle. Removing any one of these components and a fire cannot occur, or continue. BUILT ENVIRONMENT

2. FIRE TRIANGLE BUILT ENVIRONMENT

3. Sources of Ignition Friction Hot surfaces Electrical shorts and electrical equipment Static electricity Tools Open flames Heating systems BUILT ENVIRONMENT

4. Classes of Fire Classification according to type of material under fire: Class A fires; involving solid materials - paper, wood, fabrics and so on. Cooling by water or spray foam is the most effective way of extinguishing this type of fire. Class B fires; involving flammable liquids such as petrol, oils, fats; foam and dry powder extinguishers should be used. Class C fires; which are fuelled by flammable gases such as natural gas, butane and so on. Priority must be given to shutting off the source of fuel and the fire should be tackled with dry powder. Class D metal fires; involving metals such as aluminum and magnesium; special powders are required in such situations. Class E fires; in which live electrical equipment is involved (sometimes known as ‘electrical fires’). Non-conducting agents such as powder and carbon dioxide must be used BUILT ENVIRONMENT

5. Classification according to the hazard of occupancy Extra light hazard; Non-industrial occupancies like hospitals, hotels, libraries, office buildings, schools, museums, nursing homes, and prisons. Ordinary hazard; Commercial and industrial occupancies involving handling combustible materials. Under this class there are four groups of occupational fire hazards: Light group; butcheries, breweries, restaurants, coffee shops, and cement works Medium group; bakeries, laundries, garages, potteries, engineering shops High group; aircraft factories, leather factories, carpet factories, plastic factories, warehouses, departmental stores, printing rooms, saw mills chemical labs, and tanneries Special group; cotton mills, distillers, film and television studios, and match factories. Extra high hazard; Commercial and industrial occupancies involving handling highly inflammable materials such as; celluloid works, foam plastics, rubber factories, paint and varnish factories, wood and wool works, oil and other flammable liquids. BUILT ENVIRONMENT

6. Fire Detectors Heat and flame detectors; have three basic operating principles: Fusion; melting of a metal rather like a normal electrical fuse which operates a switch thus closing an electrical alarm circuit. Expansion; a bimetallic strip is used which expands when heated and makes contact with an open electrical circuit, thus closing it and sounding an alarm. Flame (heat) and smoke detectors; an infra-red beam is transmitted across the protected area. The smoke and heat interfere with the transmission of the beam; this is detected by the receiving unit and the alarm is initiated. BUILT ENVIRONMENT

7. Smoke Detectors • Ionization detectors; work on the principle that ions are absorbed by smoke particles. Some of the ions are absorbed by the smoke and the ion flow across the detection chamber is reduced; this change is detected and the alarm operates. • Light scatter detectors; contain a photoelectric cell fitted in a chamber at right angles to a light source. Smoke entering the chamber scatters the light and the resulting disturbance triggers an alarm. • Obscuration detectors; work on the opposite basis to the light scattering principle in that when the light which normally impinges on the photoelectric cell is obscured by smoke, the alarm is triggered. BUILT ENVIRONMENT

8. Fire Protection of Buildings There are four categories of fire protection systems for buildings • Portable extinguishers • Fixed foam, carbon dioxide, and dry powder extinguishers • Fixed riser and hose-reel systems • Sprinkler systems BUILT ENVIRONMENT

9. Portable Fire Extinguishers • Water or spray foam fire extinguisher; suitable for class A fires involving solid materials - paper, wood, fabrics and so on. • Foam and dry powder extinguishers; suitable for class B fires involving flammable liquids such as petrol, oils, fats; should be used. • Dry powder extinguisher;suitable for class C fires which are fuelled by flammable gases such as natural gas, butane and so on. • Special powder extinguisher; suitable for class D metal fires involving metals such as aluminum and magnesium. They work by simply smothering the fire with powdered copper Non-conducting agents such as powder and carbon dioxide extinguishers; suitable for class E fires in which live electrical equipment is involved BUILT ENVIRONMENT

10. Portable Fire Extinguishers • Halotron 1 extinguishers; like carbon dioxide units, are for use on class B and C fires. Halotron 1 is an ozone-friendly replacement for Halon 1211. It discharges as a liquid, has high visibility during discharge, does not cause thermal or static shock, leaves no residue, and is non-conducting. These properties make it ideal for computer rooms, clean rooms, telecommunications equipment, and electronics. • FE-36 (Hydrofluorocarbon-236fa) extinguishers; The FE-36 agent is less toxic than both Halon 1211 and Halotron 9. In addition, it has zero ozone-depleting potential. • Water mist extinguishers; are ideal for Class A fires where a potential Class C hazard exists. Unlike an ordinary water extinguisher, the misting nozzle provides safety from electric shock and reduces scattering of burning materials. This is one of the best choices for protection of hospital environments, books, documents, and clean room facilities. In non-magnetic versions, water mist extinguishers are the preferred choice for MRI or NMR facilities or for deployment on mine sweepers. BUILT ENVIRONMENT

11. Portable Fire Extinguishers BUILT ENVIRONMENT

12. Fixed Fire Extinguishers • Fixed Foam Extinguishers: Buildings containing flammable liquids normally have a piping system installed in the protected areas in the building with an inlet in the street through which foam is pumped. The opening is protected by a strong glass panel and is marked ‘FOAM INLET’. The fire brigade will smash the glass to feed the inlet. • Fixed Carbon Dioxide Extinguishers: This system consists of a piping network with nozzles attached and located in the protected areas. The system is connected to a fixed supply of CO2. This system does not cause any side effect as it leaves no residue after its application. BUILT ENVIRONMENT

13. Fixed Fire Extinguishers (cont..) • Dry Powder Systems:Dry powdered extinguishing chemical agents under pressure of dry air or nitrogen are discharged over the burning materials. Normally, this system is suitable for application on liquid and electrical equipment fires. BUILT ENVIRONMENT

14. Standpipe/Riser and Hose-reel System A rising main consists essentially of a pipe (of 50 mm minimum diameter) installed vertically in a building with a fire service and has inlet at the lower end and outlets at each floor inside the building. (See next page) BUILT ENVIRONMENT

15. Standpipe/Riser and Hose-reel System HOSE REEL BREAKTANK PUMP SYSTEM BUILT ENVIRONMENT

16. Standpipe/Riser and Hose-reel System There are two types of risers: • WET RISERS; Wet risers are kept permanently charged with water which is then immediately available for use on any floor with an outlet. Buildings above 60 meters in height should be provided with wet risers. Wet risers in building should not be used for any other purpose. The water supply system to the riser should be capable of providing a pressure of 410 kPa at the highest outlet. Lower outlets should be protected against excessive pressure whereby pressures should limited to 520 kPa maximum at any outlet. Wet riser system is always the preferred system unless freezing conditions may occur. In this case the dry riser system is to be used. BUILT ENVIRONMENT

17. Standpipe/Riser and Hose-reel System • Dry risers; Dry risers are similar to wet risers but are kept empty of water. When required, they will be charged by fire service pumps at ground level. Dry risers should only be installed where prompt attention can be relied upon or where buildings are not fire sensitive such as all-concrete buildings. Appropriate occupants training will be required when such systems are installed. The most common material used for standpipes is steel. Internal hose reels may be fitted inside buildings and should be sufficiently light and easily manipulated to be used by employees for a first aid fire protection. BUILT ENVIRONMENT

18. Automatic Sprinkler Systems BUILT ENVIRONMENT

19. Types of Automatic Sprinkler Systems • In general, sprinkler systems may be classified into two main types: wet-pipe and dry-pipe systems • Wet-pipe System; In the wet-pipe system the pipe work is fully charged with water at all times and thus, it is the fastest system in delivering water. This system is recommended except when freezing conditions may exist or accidental mechanical damage to sprinkler head may result in property loss or damage. Therefore, this system should not be used in spaces designated for electrical equipment such as computers, switch boards and alike. BUILT ENVIRONMENT

20. Wet-pipe System Schematic of wet-pipe sprinkler system BUILT ENVIRONMENT

21. Types of Automatic Sprinkler Systems • Dry-pipe system:In this system no water is introduced into the piping network until a fire occurs. The dry-pipe systems are used where conditions are such that freezing may occur due to weather or other conditions such as cold stores where the temperature is artificially maintained close to, or below freezing. In dry type systems the pipes are kept charged, at all times, with air or nitrogen under pressure. Activation of a sprinkler head by heat released from a nearby fire results in a pressure loss which in turn activates a dry pipe valve which opens allowing water to enter the piping network and sprayed through opened sprinkler heads. The disadvantage of this system is that accidental damage to a sprinkler head or gas leakage may falsely indicate the existence of fire and activate the system causing property damage. To avoid these unfavorable characteristics of dry-pipe system a preaction valve is used resulting in what is termed the "preaction system". BUILT ENVIRONMENT

22. Dry-Pipe System Schematic of dry-pipe sprinkler system BUILT ENVIRONMENT

23. Types of Automatic Sprinkler Systems • Preaction System:This system is a dry-pipe system with a preaction valve activated by a separate fire detection system that is more sensitive to fire than sprinkler heads. The fire detection system may consist of smoke- or flame-sensitive detection sensors that signal the actuators to open the preaction valve allowing water to flow through the sprinkler heads that are already opened by heat from fire. Thus, this system is much safer than the dry-pipe system as the water is allowed to enter the piping system only if fire occurs. BUILT ENVIRONMENT

24. Preaction System Schematic of preaction sprinkler system BUILT ENVIRONMENT

25. Types of Automatic Sprinkler Systems • Deluge System:This system is also a dry-pipe system with sprinkler heads (or nozzles) open all the time. The system is equipped with "deluge" valve operated by heat, smoke, or flame sensitive sensors. Upon valve opening water discharges out of all sprinkler heads simultaneously. BUILT ENVIRONMENT

26. Deluge System Schematic of deluge sprinkler system BUILT ENVIRONMENT

27. SPRINKLER BUILT ENVIRONMENT

28. SPRINKLER BUILT ENVIRONMENT

29. SPRINKLER Upright sprinkler Pendent sprinkler BUILT ENVIRONMENT

30. Discharge Diagram For Standard Sprinklers BUILT ENVIRONMENT

31. SPRINKLER BUILT ENVIRONMENT

32. Temperatures and Identification Colors of Sprinklers BUILT ENVIRONMENT

33. PARTS IDENTIFICATION BUILT ENVIRONMENT

34. SPRINKLER DISTRIBUTION ARRANGEMENTS BUILT ENVIRONMENT

35. Design of Hose Reel System General guidelines for the design of hose-reel systems have been developed by different codes of practice. These are: • Nozzle: (a) Minimum pressure at the nozzle, P = 200 kPa (b) Flow rate at each nozzle: q = 0.4 l/s (Hall, p. 39) q = 0.5l /s (Code, p. 55) (c) Hose-reel type and size: Type: Rubber hose/flexible (BS3169) Size: Lengths for two different diameters are given in the following table (d) Coverage: 418 m2/hose BUILT ENVIRONMENT

36. Design of Hose Reel System General guidelines for the design of hose-reel systems (Jordanian Code) • Nozzle Size: BUILT ENVIRONMENT

37. Design of Hose Reel System * Nozzle diam 4.5 mm, ** nozzle diam 6.4 mm, *** it is allowed to lower the pressure according to hydraulic calculation but not less than operating pressure. BUILT ENVIRONMENT

38. Design of Hose Reel System * Operating pressure 3 bar, ** operating pressure 1.25 bar BUILT ENVIRONMENT

39. Design of Hose Reel System * Operating pressure 3 bar, ** operating pressure 1.25 bar BUILT ENVIRONMENT

40. SYSTEM FLOW RATE • For systems using 65mm diameter hose: • 31.5 – 78.8 lt/s for high and special hazards • 15.8 – 78.3 lt/s for light and ordinary hazards • For systems using 40 mm diameter hose . • 6.3 lt/s for light and ordinary hazards. • For systems using 19 or 25 mm diameter hose • 1 lt/s BUILT ENVIRONMENT

41. Design of Hose Reel System Table 1 hose diameter vs. length BUILT ENVIRONMENT

42. Design of Hose Reel System • Supply Pipe/Riser: • Minimum number of hoses operated simultaneously: • 3 at 0.4l/sgiving 1.2 l/s (Hall, p. 39) • 2 at 0.5l /sgiving 1.0 l/s (Code, p. 55) • Pressure at the connection to the hose reel (Code, p. 55): • P=1.25 bar for a nozzle of 9.4 mm diameter (Code) • P= 3.0 bar for a nozzle of 4.8 mm diameter (Code) BUILT ENVIRONMENT

43. Design of Hose Reel System Riser size: Table 2: Riser diameter vs. building height BUILT ENVIRONMENT

44. Design of Hose Reel System • Tank: watersupply/storage tank size = 1.6 m3 (Hall) = 1.125 m3 (Code, p. 55) • Hose-Reel assembly type: • Fixed: the least expensive • Swinging: more flexible for drawing off the hose • Recessed-swinging: good for corridors • Pumping specifications (if needed): • 2.3l / s discharge capacity • duplicate pumps for maintenance BUILT ENVIRONMENT

45. Design of Hose Reel System Example: A five storey building with floor area of 800m2 (28x15 m) is to be equipped with hose-reel fire fighting system. Size the system for down-feed and up-feed water supply for a light fire hazard classification. The height of each floor is 3.2m. BUILT ENVIRONMENT

46. Design of Hose Reel System Solution: • According to the coverageof 412 m2 per hose reel, two hose-reels on each floor is sufficient to cover the whole floor area. • Assume 2 hoses operating simultaneously, the riser flow rate is then 1.0 l/s (0.5 l/s, each.) • The hose length is chosen from Table 1 as 30m with diameter of 19mm. BUILT ENVIRONMENT

47. Design of Hose Reel System A storage tank of 1.6 m3 is capable of providing two hose reels at 1.0 l/s total flow rate for 1600 seconds (or 27 minutes) duration. We also choose a nozzle with 4.8 mm diameter (Pressure connection to reel=3.0 bar.) We further choose the riser to be 50 mm in diameter since the building height is just slightly greater than 15 m (i.e., 16 m) as the pump will take care of the difference. BUILT ENVIRONMENT

48. Design of Hose Reel System The only item left is the pump size. So, we size the pump as follows: • Pressure required at point A is 3 bar (3.0e+5 Pa or 30.6 m head). • Static pressure head at point A is 15 m (up-feed) or 3.0 m down-feed. • Friction head loss Hf calculated using Thomas Box formula • q = {(d5 *Hf)/(25*L*105)}1/2 • Hf = q2*25*L*105/d5 BUILT ENVIRONMENT

49. Design of Hose Reel System Taking L= 1.5 L physical= 1.5*15 = 22.5 m (up-feed) = 1.5*3 = 4.5 m (down-feed) Hf = q2*25*L*105/d5 = 0.18 m (up-feed) = 0.04 m (down-feed) BUILT ENVIRONMENT

50. Design of Hose Reel System • Total head is then: • Htotal =HA + H f + Hstatic • =30.6+0.18+15=45.78 m • (up-feed) =30.6+0.04-3.0 = 27.64 m (downfeed) • Thus the system specifications are: BUILT ENVIRONMENT