Upon completion of this unit of study, the student should be able to: 1. Identify the term fire stream and the four purposes of a fire stream.

Transcription

1

2

3 UNIT OBJECTIVES Upon completion of this unit of study, the student should be able to: 1. Identify the term fire stream and the four purposes of a fire stream. 2. Identify the advantages and disadvantages of using water as an extinguishing agent. 3. Identify the three types of fire streams and the difference between a straight stream and a solid stream. 4. Define the following terms: gpm, psi, friction loss, water hammer, and nozzle reaction. 5. Demonstrate how to open and close a nozzle and identify methods of preventing damage to a nozzle and associated equipment. 6. Demonstrate proper methods of handling fire streams. 7. Identify the characteristics of various nozzles. 8. Describe the principle of foam generation and define common causes for the poor generation of foam and identify the procedures for correcting each. 9. Identify the advantages, characteristics, and precautions for use of the various types of foam. 10. Assemble and operate a foam fire stream arrangement given the appropriate equipment. Fire Streams - 1

4 NFPA STANDARDS Successful completion of the information in this section is necessary to fulfill the requirements of the following sections of NFPA : Fire Fighter I Standard * Attack an interior structure fire operating as a member of a team, given an attack line, ladders when needed, personal protective equipment, tools, and an assignment, so that team integrity is maintained, the attack line is deployed for advancement, ladders are correctly placed when used, access is gained into the fire area, effective water application practices are used, the fire is approached correctly, attack techniques facilitate suppression given the level of the fire, hidden fires are located and controlled, the correct body posture is maintained, hazards are recognized and managed, and the fire is brought under control. (A) Requisite Knowledge. Principles of fire streams; types, design, operation, nozzle pressure effects, and flow capabilities of nozzles; precautions to be followed when advancing hose lines to a fire; observable results that a fire stream has been properly applied; dangerous building conditions created by fire; principles of exposure protection; potential long-term consequences of exposure to products of combustion; physical states of matter in which fuels are found; common types of accidents or injuries and their causes; and the application of each size and type of attack line, the role of the backup team in fire attack situations, attack and control techniques for grade level and above and below grade levels, and exposing hidden fires. (B) Requisite Skills. The ability to prevent water hammers when shutting down nozzles; open, close, and adjust nozzle flow and patterns; apply water using direct, indirect, and combination attacks; advance charged and uncharged 38 mm (1 in.) diameter or larger hose lines up ladders and up and down interior and exterior stairways; extend hose lines; replace burst hose sections; operate charged hose lines of 38 mm (1 in.) diameter or larger while secured to a ground ladder; couple and uncouple various handline connections; carry hose; attack fires at grade level and above and below grade levels; and locate and suppress interior wall and subfloor fires. 2 - Fire Streams

5 NFPA STANDARDS Fire Fighter II Standard 6.3.1* Extinguish an ignitible liquid fire, operating as a member of a team, given an assignment, an attack line, personal protective equipment, a foam proportioning device, a nozzle, foam concentrates, and a water supply, so that the correct type of foam concentrate is selected for the given fuel and conditions, a properly proportioned foam stream is applied to the surface of the fuel to create and maintain a foam blanket, fire is extinguished, reignition is prevented, team protection is maintained with a foam stream, and the hazard is faced until retreat to safe haven is reached. (A) Requisite Knowledge. Methods by which foam prevents or controls a hazard; principles by which foam is generated; causes for poor foam generation and corrective measures; difference between hydrocarbon and polar solvent fuels and the concentrates that work on each; the characteristics, uses, and limitations of fire fighting foams; the advantages and disadvantages of using fog nozzles versus foam nozzles for foam application; foam stream application techniques; hazards associated with foam usage; and methods to reduce or avoid hazards. (B) Requisite Skills. The ability to prepare a foam concentrate supply for use, assemble foam stream components, master various foam application techniques, and approach and retreat from spills as part of a coordinated team. Fire Streams - 3

6 I. Fire Streams (Essentials p. 717) A. Fire stream: a stream of water or other extinguishing agent after it leaves the fire hose and nozzle until it reaches the desired point B. Purposes of fire streams 1. Apply a water or foam stream directly to the burning material to reduce its temperature 2. Reduce high atmospheric temperature and absorb and/or disperse hot smoke and gases from a heated area in a confined space 3. Create a barrier between a fuel and fire 4. Reduce the temperature over an open fire and thus permit a closer proximity with hand hose lines to effect extinguishment 5. Protect fire fighters and property from heat through the use of fire streams as a water curtain 6. Disperse smoke and gases from a heated area II. Extinguishing Principle of Water A. Primary principle of extinguishment is by cooling the fuel below ignition temperature 1. Can also smother by diluting or excluding oxygen 2. Vaporization a. Process that changes a liquid into a gaseous state 4 - Fire Streams

7 b. The rate of vaporization depends on the substance involved, heat, and pressure 3. Heat absorption involves the heat required to raise a substance's temperature and the additional heat to change state a. Specific heat is the amount of energy required to raise the temperature of a specified mass of a substance by one degree b. Energy is also needed to change a liquid to a gas phase c. Latent heat of vaporization: quantity of heat absorbed by a substance at the point at which it changes from a liquid to a gas 4. When water from a fire stream is broken into small droplets, such as from a fog nozzle, it absorbs heat and converts to steam more quickly than in a compact form, such as from a solid-bore nozzle a. How much heat a fire stream absorbs is dependent on the surface area of water put into an area b. The more surface area exposed to heat, the more heat absorbed c. A fire stream can be ineffective unless it reaches the fire with enough water to absorb the heat being produced d. In some situations, a fog stream might evaporate before reaching the burning fuel and a solid stream is needed to reach the seat of the fire Fire Streams - 5

8 5. Effective extinguishment generally requires steam production a. Water converted to steam absorbs more heat than water heated at its boiling point b. Water converted into steam occupies several hundred times its original volume to aid in extinguishment c. At 212 F water expands about 1,700 times d. One cubic foot of water (7.48 gallons) will occupy a space of 1,700 cubic feet when converted into steam e. At 500 F, water expands 2,400 to 1 f. At 1,000 F, water expands 4,200 to 1 g. The volume of steam produced is also dependent on the amount of water applied B. Other advantages of water as an extinguishing agent 1. Readily available and relatively inexpensive 2. Greater heat-absorbing capacity than other common extinguishing agents 3. Water changing to steam requires a large amount of heat (high latent heat of vaporization) 4. Can be applied a variety of ways a. Solid stream (1) Fire stream that stays together as a solid mass 6 - Fire Streams

9 (2) Produced by a solid-bore nozzle and should not be confused with a straight stream b. Fog stream: stream of finely divided particles used for fire control c. Broken stream: stream broken into coarsely divided drops C. Disadvantages of water as an extinguishing agent: 1. Has considerable surface tension 2. Reacts with certain materials 3. Freezes at normal winter temperatures 4. Low viscosity (resistance) 5. Conducts electricity 6. Steam can cause serious burns to personnel III. Pressure Loss or Gain A. Pressure: the application of force 1. Pounds-per-square-inch = psi 2. Gallons-per-minute = gpm B. Friction loss 1. The part of the total pressure that is used to overcome friction while forcing water through pipes, fittings, fire hose, and adapters Fire Streams - 7

10 2. As water flows through hose, couplings, and appliances, water molecules rubs against the sides of these items and friction is produced 3. The most common friction loss occurs in the hose between the pumper and the nozzle a. If the speed of the water traveling through a hoseline is increased above its practical limit, the friction becomes so great that the water is agitated by resistance b. In general, the smaller the hose diameter and longer the hose lay, the higher the friction loss 4. Factors which affect the amount of friction loss: a. Amount of water moving through the hose b. Size of hose c. Length of hose layout d. Number of bends and kinks in hose e. Obstructions in water stream f. Rough linings in the hose g. More adapters than necessary h. Damaged couplings C. Elevation loss and gain 1. Elevation refers to the position of the nozzle above or below the pumper 8 - Fire Streams

11 2. Pressure loss occurs when the nozzle is above the pump 3. Pressure gain occurs when the nozzle is below the pump D. Water hammer 1. The sudden surge of pressure in the water system (hose, pipe, fire pump) resulting from the sudden stoppage of water flow through the system, such as the abrupt closing of a nozzle or valve 2. Can damage water mains, fire hose, hydrants, and pumps 3. To prevent water hammer, all valves, including nozzles, hydrants, and hose clamps, must be opened and closed slowly 4. A brief application of water fog at about 150 gpm for about one second will not cause water hammer E. Nozzle reaction 1. The back pressure (kick back) felt while water is being discharged from a nozzle 2. Factors affecting the amount of nozzle reaction: a. Nozzle pressure b. Amount of water being discharged (gpm) c. The fire stream pattern Fire Streams - 9

12 IV. Fire Stream Nozzles (Essentials p. 724) A. Fire stream sizes 1. Low-volume: less than 40 gpm, typically supplied by 1" hoselines 2. Handline stream: 40 to 350 gpm, typically supplied by 1 1 / 2 " to 3" hoselines 3. Master stream: greater than 350 gpm, typically supplied by 2 1 / 2 " or 3" hoselines or large diameter hose 4. The amount of water discharged is determined by the nozzle design and water pressure at the nozzle 5. All fire streams must have: a. A pressuring device: a pump b. Hose c. An extinguishing agent: water d. A nozzle B. Solid stream nozzles 1. A stream of water shaped by a fixed orifice (solidbore nozzle) previous to discharge a. Can reach areas other stream types may not reach b. Can be affected by gravity, friction of the air, and wind 10 - Fire Streams

13 2. Designed so the shape of the water in the nozzle is gradually reduced until it reaches a point a short distance from the outlet a. The nozzle becomes a smooth cylinder with a length 1 to 1 1 / 2 times its inside diameter b. Gives the water its round shape before discharge 3. Characteristics of solid streams a. A stream that does not lose its continuity until the point of breakover where it falls into showers of spray b. A stream that is solid enough to keep its shape even in a breeze 4. Flow capacities of solid stream nozzles a. Handheld nozzle sizes and flows at 50 psi nozzle pressure: (1) 3 / 4 " = 120 gpm (2) 7 / 8 " = 160 gpm (3) 1" = 200 gpm (4) 1 1 / 8 " = 265 gpm (5) 1 1 / 4 " = 326 gpm b. Solid stream nozzle for master stream devices operate at 80 psi nozzle pressure and can flow: (1) 1 1 / 4 " = 413 gpm Fire Streams - 11

14 (2) 1 3 / 8 " = 500 gpm (3) 1 1 / 2 " = 596 gpm (4) 1 5 / 8 " = 700 gpm (5) 1 3 / 4 " = 813 gpm (6) 1 7 / 8 " = 935 gpm (7) 2" = 1063 gpm 5. Advantages of solid streams a. Greater reach and penetration b. Operate at less pressure and reduce nozzle reaction c. Less likely to disturb thermal layer d. Maintains better visibility for fire fighters e. May be easier to maneuver because of lower pressures f. Less prone to clogging with debris g. Produce less steam conversion than fog nozzles h. Can be used to apply compressed-air foam 6. Disadvantages of straight streams a. Only one stream pattern available b. Hoselines may be more easily kinked c. Less heat absorption per gallon delivered 12 - Fire Streams

15 C. Fog stream nozzles 1. Create a stream of fine water droplets to expose the maximum water surface for heat absorption 2. Most fog nozzles are adjustable into: a. Straight stream b. Narrow fog stream (15 o to 45 o ) c. Wide-angle fog stream (45 o to 80 o ) 3. A straight stream from a fog nozzle does not have the solid core of water as does the stream from a solid stream nozzle 4. Factors which influence the reach of a fog stream: a. Gravity b. Water velocity c. Stream pattern d. Water droplet friction with air e. Wind 5. Waterflow adjustment a. Manually adjustable nozzles (1) Allow for the adjustment of the gallons being discharged by turning the selector ring on the nozzle (2) Each setting gives a constant flow as long as there is adequate nozzle pressure Fire Streams - 13

16 (3) Handline nozzles may have settings from 10 gpm to 250 gpm, depending on the size hose (4) Adjustments must be made in small increments or there can be a sudden change in nozzle reaction b. Automatic (constant-pressure) nozzles (1) Allow for the adjustment of the gallons being discharged by opening and closing the shutoff valve on the nozzle to different degrees (2) Allow the operator to vary flow rate while maintaining a constant pressure 6. Most fog stream nozzles are designed to operate at nozzle pressure of 100 psi at the base of the nozzle 7. Advantages of fog stream nozzles: a. Discharge pattern can be adjusted b. Amount of water can be adjusted c. Can aid in ventilation d. Help dissipate heat through amount of exposed surface area for heat absorption 8. Disadvantages of fog stream nozzles: a. Do not have the reach or penetration power of solid streams b. Can be broken up by wind 14 - Fire Streams

17 c. Can disturb thermal laying and cause steam burns d. Can push air into the fire area and contribute to fire spread D. Broken stream nozzles 1. Designed to cover the most space possible with high heat absorption with coarsely divided drops 2. Types: a. Water curtain nozzles b. Cellar nozzles c. Distributors 3. Advantages a. Coarse drops absorb more heat than a solid stream b. Greater reach and penetration than a fog stream c. Can be effective with confined space fires, such as attics, basements, wall spaces, and underground vaults 4. Disadvantages a. May have enough continuity to conduct electricity b. May not reach some fires Fire Streams - 15

18 E. Special stream nozzles 1. Designed for special purposes to meet specific needs 2. Types: a. Penetrating/piercing nozzles b. Foam nozzles G. Stream straighteners 1. Vanes set into the water stream 2. Reduce the whirling action of the water stream before entering nozzle H. Nozzle handling precautions 1. Keep nozzles closed during makeup or movement of the line 2. Do not drop or drag nozzles 3. Release trapped air from hose lines before moving into fire area 4. Operate all valves and nozzles slowly to prevent water hammer 5. Move forward of nozzle if control of the line is lost, if possible 6. In confined areas, improper use of nozzle may upset the thermal balance 16 - Fire Streams

19 I. Operating nozzles 1. Fire fighters should be positioned on the same side of the hoseline J. 2. Before opening the nozzle back up personnel should communicate they are ready 3. The nozzle is opened slowly and fully 4. Personnel must retain control of the nozzle and hoseline at all times Nozzle control valves 1. Ball valve a. Most common nozzle valves in use b. A ball with a smooth waterway through it, is suspended from both sides of the nozzle body and seals against a seat c. The ball is rotated 90 degrees by moving a valve handle ("nozzle bale") d. When the bale is pulled backward, the nozzle is opened, when pushed forward the nozzle is closed e. When open the waterway through the ball is in line with the nozzle allowing water to flow through it f. If partially opened, the ball will cause turbulence in the water stream and may affect the desired pattern Fire Streams - 17

20 2. Slide valve a. The slide control valve seats a movable cylinder against a shaped cone to turn off water flow b. Changing the sliding cylinder relative to the cone either increases or decreases flow c. Water flows through the nozzle without turbulence d. Task Force Tips (TFT ) is the most common brand to use this technology in their nozzles 3. Rotary control valve a. Found only on rotary control fog nozzles b. Consist of an external barrel guided by a screw rotating around an interior barrel c. Controls both the flow and discharge pattern K. Inspection and maintenance of nozzles 1. Check for external damage to the nozzle 2. Look for internal damage and debris 3. Check the nozzle bail or handle for function by moving it to the OPEN and CLOSED position 4. Check the gallonage setting control by moving it to all of the various gallonage settings 5. Check pattern adjustment for function by rotating it 18 - Fire Streams

21 6. Check nozzle coupling gasket for defects, age, and ability to return to normal shape by pinching gasket between the thumb and index fingers V. Fire Fighting Foam and Foam Streams (Essentials p. 734) A. Water will have limited effect in flammable liquid emergencies 1. Proper application of foam requires understanding the various types of foam and their application 2. To be effective, foam concentrates must be matched to the fuel to which they are applied B. Fire fighting foam forms a blanket of foam on the surface of burning fuels which excludes oxygen and stops the burning process 1. The water in foam is slowly released and has a cooling effect on the fuel 2. With ignitable liquids, the foam blanket also reduces the releases of flammable vapors from the liquid, preventing reignition of the fuel C. Extinguishing characteristics of foam: 1. Suppressing: prevents release of vapors 2. Separating: creates a barrier between the fuel and fire 3. Cooling: lowers temperature of the fuel 4. Penetrating: lowers the surface tension of water and allows it to penetrate into deep-seated fires Fire Streams - 19

22 D. Hydrocarbon and polar solvent fuels 1. Hydrocarbon fuels float on water and foam will float on top of these fuels a. Gasoline b. Crude oil c. Fuel oil d. Benzene e. Kerosene f. Jet fuel 2. Polar solvents such as alcohol, acetone, acids, ketone, and lacquer thinner a. Have an attraction for water b. Fire fighting foam must be alcohol resistive to be effective on these liquids E. Foam production 1. Foam (finished foam): completed product after air is introduced into the foam solution 2. Foam concentrate: raw liquid foam before the introduction of water and air 3. Foam proportioner: introduces foam concentrate into the water stream a. Foam must be proportioned with water and aerated with air to be used 20 - Fire Streams

23 b. These elements must be in correct ratios to produce foam c. Aeration should produce an adequate amount of foam bubbles 4. Foam solution: mixture of foam concentrate and water before air is introduced 5. Foam expansion refers to an increase in volume when a foam solution is aerated and depends on: a. Type of foam concentrate used b. Accurate proportioning (mixing) of the solution c. Quality of foam concentrate d. Aspiration method 6. Basic foam types a. Low-expansion foam: has an air/solution ratio of up to 20 parts finished foam for every part of foam solution (20:1 ratio) b. Medium-expansion foam: has an air/solution ratio of from 20:1 to 200:1 parts finished foam for every part of foam solution through hydraulically operated nozzle-style delivery devices c. High-expansion foam: the rate is from 200:1 to 1,000:1 F. Types of foam concentrates 1. Foam concentrates must match the fuel to which they are applied Fire Streams - 21

24 a. Class A foams are not designed for Class B fires b. Class B foams designed for hydrocarbon fires will not extinguish polar solvent fires c. The fuel involved must be identified before applying foam 2. Class A foams a. A wetting agent (hydrocarbon surfactants) is added that reduces the surface tension of water allowing it to soak into combustible material b. Characteristics (1) Can be used with ordinary nozzles (2) Can be pre-mixed in the booster tank (3) Good penetrating capabilities (4) Mildly corrosive c. Can be propelled with compressed gas systems d. Only for Class A fires 3. Class B foams a. Designed for use on unignited or ignited Class B flammable or combustible liquids b. The rate of application depends on: (1) Type of foam concentrate being used (2) Whether or not the fuel is on fire 22 - Fire Streams

25 (3) Whether a hydrocarbon or polar solvent is involved (4) If the fuel is spilled or contained in a tank (5) If the foam is applied by a fixed system or portable equipment c. Unignited spills require less application than burning spills (1) Heat and thermal drafts do not attack the finished foam (2) A foam blanket 4 inches thick should be applied to the fuel's surface (3) If ignition occurs, the foam should be flowed until extinguishment is complete (4) Stopping and starting can allow the fire to consume the foam blanket in place d. Protein foam: chemically broken down protein solids resulting in a protein liquid concentrate (1) Low expansion (2) Excellent water-retention capabilities (3) High heat resistance and reignition resistance (4) Do not allow foam to plunge into burning liquids (5) Apply in a finished foam spray or apply indirectly Fire Streams - 23

26 (6) Requires a close approach by fire fighters (7) Unlike other synthetic foams, protein foams are biodegradable e. Fluoroprotein foam: protein and synthetic based (1) Long term vapor suppression (2) Excellent heat resistance (3) Fast fire knockdown (4) Can be plunged into the fuel or used for subsurface injection (5) Nontoxic and biodegradable after dilution f. Film forming fluoroprotein foam (FFFP): protein based with added surfactants to reduce burnback (1) Develops a continuous floating film on hydrocarbon fuels (2) Excellent heat resistance (3) Fast fire knockdown (4) Alcohol resistant formula can be used on polar solvents at 6% and hydrocarbons at 3% (5) Nontoxic and biodegradable after dilution g. Aqueous film forming foam (AFFF): synthetic based (1) Can be used through regular fog nozzles 24 - Fire Streams

27 (2) Spreads a fast-healing, continuous-floating film over fuels (3) Fast fire knockdown (4) Can be affected by freezing and thawing (5) May be applied directly on fuel surface (6) Must cover the entire fuel surface (7) May be used with subsurface injection (8) Foam blanket continues to drain water releasing more film allowing AFFF to "heal" over areas where the blanket has been disturbed (9) Can be used as wetting agent to penetrate Class A fuels h. Alcohol-Resistant AFFF (1) Can be used on both polar solvent and hydrocarbon fuels (2) Forms a membrane on polar solvents to prevent foam blanket destruction (3) Fast flame knockdown (4) Good burnback resistance i. High-expansion foam: low water content foam minimizes water damage and runoff (1) High air-to-solution ratio: 200 to 1 to 1,000 to 1 Fire Streams - 25

28 (2) Poor heat resistance (3) Will attack the surface of galvanized steel and raw steel with prolonged exposure (4) Outdoor use is not recommended (5) Can be used: (a) On Class A and some Class B fires (b) To flood confined spaces (c) To reduce vaporization from liquefied natural gas spills j. Hazardous materials vapor mitigating foam (1) Special low expansion foams designed for use on unignited spills of hazardous liquids (2) Unignited chemicals change the ph or remove the water from fire fighting foams rendering them ineffective G. Foam proportioning 1. Foam concentrates must be proportioned with water at the percentage for which they are designed a. The percentage rate varies with the intended fuel and is marked on every foam container b. Most fire fighting foams are designed to be mixed at 3% to 6% concentrate in water (1) 3% foam concentrate is to be mixed 97 parts water and 3 parts concentrate 26 - Fire Streams

29 (2) 6% foam concentrate is to be mixed 94 parts water and 6 parts concentrate c. Class A foams are proportioned for their specific objective (1) A higher percentage concentrate can be used to produce a thick foam for exposure protection and fire breaks (2) A lower percentage mixture can produce a thin foam that sinks into a fuel's surface d. Some multipurpose Class B foams are designed for hydrocarbon and polar solvent fuels at different concentrations (1) 3% for hydrocarbons (2) 6% for polar solvents 2. Proportioning equipment may be designed for mobile use and others for fixed fire protection systems 3. The selection of a proportioner depends on: a. The foam solution flow requirements b. Available water pressure c. Cost d. Intended use (truck, fixed, portable) e. The agent to be used Fire Streams - 27

30 4. Induction/eduction proportioning a. Uses the pressure energy in the water stream to induct (draft) foam concentrate into the stream b. Venturi principle used in eductors (1) As water at a high pressure passes over a reduced opening, it creates a low pressure near the outlet side of the eductor (2) The low pressure creates a suction which draws the foam concentrate into the water stream 5. Injection proportioning a. An external pump or head pressure is used to force foam concentrate into a fire stream b. Commonly used in apparatus-mounted or fixed systems 6. Batch-mixing proportioning a. Concentrate is mixed with water in the apparatus water tank or portable water tank b. Commonly used with Class A foams c. Should be used as a last resort with Class B foams 7. Pre-mixing a. Water and concentrate are pre-mixed in a container 28 - Fire Streams

31 b. Used in extinguishers and vehicle-mounted tank systems c. Limited to a one time application because the tank must be completely emptied and refilled before another use H. Foam proportioners 1. May be portable or apparatus-mounted 2. Operate by either: a. Venturi action that inducts foam concentrate into the water stream b. Pressurized proportioning devices that inject concentrate into the water stream at a specified ration and higher pressure 3. Portable foam proportioner a. In-line foam eductors (1) Most common used in the fire service (2) May be connected at the pump or along the hose lay (3) Manufacturer's instructions must be followed about inlet pressure and the maximum hose lay between the eductor and nozzle (4) Operate on the Venturi Principle (5) The foam concentrate inlet to the eductor must be no more than six feet above the surface of the liquid foam concentrate Fire Streams - 29

32 (6) If the eductor in too far above the concentrate, the foam will be very lean or may not be inducted at all b. Foam nozzle eductors (1) Operate like an in-line educator but the eductor is built into the nozzle (2) Can create problems because concentrate containers must be at the nozzle and can create difficulty in relocating the line 4. Apparatus-mounted proportioners a. Installed in-line eductors b. Around-the-pump proportioners c. Balanced pressure proportioners 5. Compressed-air foam systems (CAFS) a. Apparatus may be equipped with CAFS b. A direct-inject foam proportioner mixes foam with water on the discharge side of the pump and a compressor adds air to the mix before it is discharged c. Advantages (1) Stream reach is much longer than other foam systems (2) Hoselines weigh less than those full of water or foam solution (3) Foam produced is very durable 30 - Fire Streams

33 (4) Foam adheres well to vertical surfaces d. Disadvantages (1) Adds expense to cost and maintenance of apparatus I. (2) Hose reaction may be significant (3) Additional training for personnel is necessary Foam delivery devices 1. Handline nozzles a. Solid-bore nozzles (1) Limited to certain types of Class A foam applications (2) Most often used with compressed air foam systems b. Fog nozzles (1) Can be used to produce low-expansion, short-lasting foam (2) Best used with AFFF and Class A foams (3) Should not be used for polar solvent fires because of inadequate aspiration c. Air-aspirating foam nozzles (1) Most effective for generation of lowexpansion foam Fire Streams - 31

34 (2) Introduces air into the foam solution through a venturi principle (3) Much less reach than standard fog nozzles (4) Provide maximum expansion of the foam (5) Some manufacturers have aeration attachments for fog nozzles 2. Medium and high-expansion foam generating devices a. Water-aspirating nozzles (1) Back of the nozzle is open to allow airflow (2) Foam solution passes through the nozzle in a mist that mixes with the air (3) The end of the nozzle has a screen or set of screens to break up the foam and further mix it with air b. High-expansion generators (1) Air is forced through the foam spray by a powered fan J. (2) Produces foam with a high air content (3) Typically used in total-flooding applications Causes of poor foam generation 1. Eductor and nozzle flow ratings mismatch 2. Improper cleaning of proportioning equipment 32 - Fire Streams

35 3. Air leaks at fittings 4. Too long of a hose lay on the discharge side of the eductor, creating excess back pressure 5. Nozzle too far above eductor, causing excessive elevation pressure 6. Mixing different types of foam together resulting in a mixture too viscous to pass through the eductor 7. Partially closed nozzle resulting in high nozzle pressure K. Assembling a foam fire stream system 1. Select the proper foam to be used 2. Check the eductor and nozzle to make sure that they are compatible 3. Ensure the foam concentration matches the eductor percentage rating 4. Attach the eductor to hose of proper size 5. Attach the attack hoseline and nozzle to the discharge end of eductor 6. Avoid kinks in the hose 7. Open the foam bucket and places eductor suction hose into the foam 8. Open the nozzle fully 9. Increase the water supply pressure to meet the eductor's requirement Fire Streams - 33

36 L. Foam application methods 1. Roll-on method a. Foam stream is directed at the front edge of a burning liquid and allowed to roll across the fuel's surface b. This method can be used only on a pool of fuel on open ground 2. Bank-down method a. Foam stream is directed against an object near the fuel, such as a wall or tank shell b. Foam is allowed to run down the object and onto the liquid c. The method can be used with fires and spills within diked areas or around vehicles 3. Rain-down method a. Foam stream is directed into the area over the fuel and foam floats down to the liquid's surface b. Primary method for aboveground fuel storage c. On small fires, the nozzle is swept back and forth to cover the fuel's entire surface d. On large fires, the stream can be directed at one point to allow the foam to collect there and float out across the fuel's surface 34 - Fire Streams

37 M. Foam hazards 1. Foam, either in concentrate or diluted poses little health hazard a. Can be mildly irritating to the skin and eyes b. Affected areas should be flushed with water c. Some can be harmful if ingested or inhaled 2. Most foam concentrates are mildly corrosive: all foam equipment must be thoroughly flushed after use 3. The primary environmental impact is after foam has been applied to a fire or liquid spill a. When foam decomposes, oxygen is consumed by bacteria action b. This reduction in oxygen in a waterway may kill fish and other aquatic creatures c. The chemical properties of Class B foams vary depending on the concentrate and manufacturer d. Protein-based foam are typically safer for the environment VI. Fire Streams Summary A. For water to be effective as an extinguishing agent, fire fighters must be adequately trained and proficient in the use of the various types of fire streams available 1. Personnel must understand the limitations of water as an agent Fire Streams - 35

38 2. Fire fighters need to be familiar with the use of the various nozzles within their department and the advantages and limitations of each 3. Improperly used, fire streams can cause injuries, damage equipment, and create additional fire control problems B. Fire personnel must also understand the advantages of using various types of foam and how to apply foam for the most effective result 36 - Fire Streams

39 FIRE STREAMS QUIZ Name: Date: 1. An advantage of water for use as an extinguishing agent is. a. the greater the surface area that is exposed, the more heat will be absorbed b. it has considerable surface tension c. it may react with certain materials d. it has low viscosity 2. When water converts to steam at 212 o F, it expands approximately. a. 1,000 to 1 b. 1,700 to 1 c. 2,400 to 1 d. 4,200 to 1 3. Which of the following factors does not affect the amount of friction loss? a. Size of hose b. Length of hose layout c. Amount of water moving through hose d. Pump pressure 4. Water hammer is best defined as. a. that part of total pressure that is used to overcome friction while forcing water through pipes and hose b. the sudden surge of pressure in a water system resulting from the sudden stoppage of water flow c. the back pressure felt while water is being discharged from a nozzle d. a stream of water after it leaves the fire hose until it reaches the desired point 5. Which of the following is not an advantage of solid stream nozzles? a. Can easily be used with foam b. Good reach and penetration c. Operates at less pressure d. Helps maintain visibility for fire fighters Fire Streams - 37

40 FIRE STREAMS QUIZ 6. Solid stream hand held nozzles should operate at psi and fog stream nozzles at psi. a. 80, 100 b. 50, 100 c. 100, 50 d. 100, A disadvantage of using fog stream nozzles is that. a. the discharge pattern is not adjustable b. the amount of water discharged is not adjustable c. ventilation can be hampered through their use d. the stream can be broken up by wind 8. Foam eductors operate by which of the following? a. Venturi principle b. Venturous theory c. Mason's axiom d. Diverging siphon 9. Which of the following is not a cause of poor foam generation? a. Air leaks at fittings b. Improper cleaning of proportioning equipment c. Mixing different types of foams d. Use of air-aspirating nozzles 10. For in-line eductors to function properly, the inlet to the eductor must be no more than above the level of the foam concentrate. a. 12-inches b. 3-feet c. 6-feet d. 10-feet 38 - Fire Streams

41 INSTRUCTOR'S GUIDE PRACTICAL SKILLS These Lead Instructor Practical Skills are designed to provide the Lead Instructor for a Fire Fighter I and II course with a more detailed overview of the practical skills required of all students. The appropriate skills from NFPA are listed at the front of each skill's section. Although the skills from NFPA are written as Job Performance Requirements, these have been divided into individual skill elements. This is to allow for consistency in the evaluation of each skill element. Students must successfully complete each step of each practical skill during the practical skills evaluation portion of a Fire Fighter I and II course. At the time of a Fire Fighter I and II Certification Examination, the skill steps have been prioritized to allow a student to miss a predetermined number of steps Fire Streams

42 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams Successful completion of the practical skills in this section are necessary to fulfill the requirements of the following sections of NFPA : Fire Fighter I Standard * Attack an interior structure fire operating as a member of a team, given an attack line, ladders when needed, personal protective equipment, tools, and an assignment, so that team integrity is maintained, the attack line is deployed for advancement, ladders are correctly placed when used, access is gained into the fire area, effective water application practices are used, the fire is approached correctly, attack techniques facilitate suppression given the level of the fire, hidden fires are located and controlled, the correct body posture is maintained, hazards are recognized and managed, and the fire is brought under control * Clean, inspect, and return fire hose to service, given washing equipment, water, detergent, tools, and replacement gaskets, so that damage is noted and corrected, the hose is clean, and the equipment is placed in a ready state for service. Fire Fighter II Standard 6.3.1* Extinguish an ignitible liquid fire, operating as a member of a team, given an assignment, an attack line, personal protective equipment, a foam proportioning device, a nozzle, foam concentrates, and a water supply, so that the correct type of foam concentrate is selected for the given fuel and conditions, a properly proportioned foam stream is applied to the surface of the fuel to create and maintain a foam blanket, fire is extinguished, reignition is prevented, team protection is maintained with a foam stream, and the hazard is faced until retreat to safe haven is reached. Fire Streams - 41

43 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams - NFPA , Demonstrate the Operation of a Solid-Bore Nozzle Skill Objective: The candidate shall demonstrate the operation of a solid-bore nozzle while flowing water from a hoseline. Skill Procedure: The evaluator shall have a 2 1 / 2 "or 3" hoseline off of a pumper. The evaluator shall have the candidate utilize a solid-bore nozzle. The candidate shall utilize other personnel as needed to assist with the hoselines. Students are allowed two chances at each skill for successful completion. Any step listed in italics missed shall result in failure of the skill. Otherwise, students are allowed to miss a maximum of two of the following steps and pass this skill. Items to be checked If the candidate: Solid Stream Nozzle 1. States the reason solid stream nozzles are used 2. Indicates the proper operating nozzle pressure of 50 psi for handlines 3. Utilizes the proper number of persons to effectively handle the hoselines 4. Slowly opens the nozzle 5. Moves the nozzle in different directions 6. Slowly closes the nozzle 7. Controls the nozzle in a safe and capable fashion 8. States the advantages of solid streams 9. States the disadvantages of solid streams 42 - Fire Streams

44 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams - NFPA , Demonstrate the Operation of a Fog Stream Nozzle Skill Objective: The candidate shall demonstrate the operation of a fog stream nozzle while flowing water from a hoseline. Skill Procedure: The evaluator shall have a 1 1 / 2 " or 1 3 / 4 " hoseline off of a pumper. The evaluator shall have the candidate utilize a fog stream nozzle. The candidate shall demonstrate the use of the nozzle by going through the gpm flows and the nozzle settings as indicated. The candidate shall utilize other personnel as needed to assist with the hoselines. Students are allowed two chances at each skill for successful completion. Any step listed in italics missed shall result in failure of the skill. Otherwise, students are allowed to miss a maximum of two of the following steps and pass this skill. Items to be checked If the candidate: Fog Stream Nozzle 1. States the reason fog stream nozzles are used 2. Indicates the proper operating nozzle pressure of 100 psi for fog streams 3. Utilizes the proper number of persons to effectively handle the hoselines 4. Slowly opens the nozzle 5. Moves the nozzle through the various gpm settings and nozzle settings 6. Slowly closes the nozzle 7. Controls the nozzle in a safe and capable fashion 8. States the advantages of fog streams 9. States the disadvantages of fog streams Fire Streams - 43

45 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams - NFPA , Demonstrate the Operation of Fire Stream From a Ladder Skill Objective: The candidate, given a 24 foot extension ladder in place, with protective equipment (SCBA optional), shall advance a 1 1 / 2 " or 1 3 / 4 " charged attack line, up the ladder with assistance and operate the nozzle from the ladder. Before operating the nozzle, it will be secured in place and the candidate shall perform a leg lock. Skill Procedure: The evaluator should arrange for a 24 foot extension ladder to be secured against a structure and locate one fire fighter to butt the ladder with another fire fighter assisting the candidate with the hose. The candidate shall advance the charged line up the ladder, secure the nozzle, perform a leg lock and flow the nozzle. Students are allowed two chances at each skill for successful completion. Students are allowed to miss a maximum of one of the following steps and pass this skill. Items to be checked If the candidate: 1. Positions on the ladder with a leg lock on opposite side nozzle will flow or uses a life belt 2. Has the other fire fighter push the charged hose line up the ladder to him or her (Note: additional fire fighters can be utilized to advance the hose as necessary) 3. Projects the nozzle through the ladder rungs 4. Secures the nozzle and hose with a rope or rope hose tool 5. Opens the nozzle and flows water in a controlled manner 6. Conducts the exercise in a safe and efficient way 44 - Fire Streams

46 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams - NFPA , Demonstrate Inspecting Nozzles Skill Objective: The candidate, shall demonstrate the procedures for inspecting nozzles for damage. Students are allowed two chances at each skill for successful completion. Students are allowed to miss a maximum of one of the following steps and pass this skill. Items to be checked If the candidate: 1. Checks the nozzle bail or handle for function by moving it to the OPEN and CLOSED position 2. Checks the gallonage setting control by moving it to all of the various gallonage (GPM) settings 3. Checks fog rotating ring for function by rotating it 4. Checks nozzle pattern adjustment for function by moving it to different wide fog, medium fog, straight stream, and flush settings 5. Checks nozzle coupling gasket for defects, age, and ability to return to normal shape by pinching gasket between the thumb and index fingers Fire Streams - 45

47 MISSOURI DIVISION OF FIRE SAFETY FIRE FIGHTER I & II PRACTICAL SKILLS Fire Streams - NFPA , Demonstrate the Assembly and Operation of a Foam Stream Skill Objective: The fire fighter, given the proper equipment, shall assemble and operate a foam fire stream arrangement. Skill Procedure: The evaluator should determine the type of foam generating equipment used by the authority having jurisdiction and gather the equipment and a pumper. The evaluator will provide for assistance as necessary. The candidate will assemble the equipment and, with assistance as necessary, operate the equipment. Students are allowed two chances at each skill for successful completion. Any step listed in italics missed shall result in failure of the skill. Otherwise, students are allowed to miss a maximum of two of the following steps and pass this skill. Items to be checked If the candidate: 1. Selects the proper foam to be used 2. Checks the eductor and nozzle to make sure that they are compatible 3. Ensures the foam concentration matches the eductor percentage rating 4. Attaches eductor to hose of proper size 5. Attaches attack hoseline and nozzle to the discharge end of eductor 6. Avoids kinks in the hose 7. Opens the foam bucket and places eductor suction hose into the foam 8. Opens nozzle to ensure generation of foam 9. Demonstrates the application of foam in the following methods: a. Bounces agent off walls or other obstructions b. Applies the agent in front of the burning fuel and rolls the agent onto the fuel c. In the absence of a wall of obstruction, gently lobs the agent onto the burning liquid 10. Performs the evolution without difficulty in a safe manner Fire Streams