1. Nozzles, Fire Streams, and Foam
Chapter 11
Nozzles, Fire Streams,
and Foam

2. Introduction Fires usually extinguished by water
Foam added to improve water’s extinguishment ability
For fires where water ineffective
Water and foam delivered using nozzles and fire streams
Nozzle selection important
Each fire situation requires different appliance

3. Definition of Fire Stream
Fire stream: extinguishing agent that leaves the nozzle and flows toward its target
Four elements affecting the stream:
Pump
Water
Hose
Nozzle
Proper stream has sufficient volume, pressure, and direction to reach its target

4. Nozzles
Nozzles: appliances that allow application of extinguishing agent
Two types: solid stream and fog
Combination nozzles: straight stream or adjustable spray patterns
Nozzle pressure: pressure required for effective nozzle operation
Relates to flow and reach
Nozzle flow: amount of water a nozzle provides at a given pressure

5. Figure 11-1 Nozzles showing the stream shape for straight, solid, and wide pattern streams.

6. Nozzles (cont’d.)
Nozzle reach: distance the water will travel after leaving the nozzle
Nozzle reach a function of water pressure
Affected by stream shape, water pressure, wind direction, gravity, air friction
Stream shape (stream pattern): configuration of droplets of water as they leave the nozzle
Nozzle reaction: nozzle moves in opposite direction of water flow

7. Solid Tip or Stream Deliver unbroken stream of water
Solid stream nozzle delivers water as a solid cone of water
Large droplets when bounced off wall, ceiling
Flow a factor of tip size at a certain nozzle pressure
Minimal effect of room’s thermal balance
Disadvantages: lack of volume control, lack of fog protection, higher nozzle reaction

8. Fog Nozzles
Deliver fixed spray pattern or variable combination pattern
Straight stream and spray patterns
Fog provides better heat absorption, but can change to steam
Excellent tools for hydraulic ventilation
Large quantities of smoke removed by aiming fog cone out an open window
Can also draw heat from the fire

9. Figure 11-6 Variable combination fog nozzle patterns
Figure Variable combination fog nozzle patterns. From top to bottom: straight stream, narrow fog, and wide fog.

10. Figure 11-7 Parts of a fog nozzle.

11. Straight Stream Creates a hollow type stream
Similar to solid stream pattern
Straight stream pattern must pass around the baffle of the nozzle
Creates an opening in the pattern
May allow air into the stream and reduce its reach
Newer designs have hollow effect from the tip
Short distance to refocus the stream to create solid stream with good reach and penetration

12. Figure 11-11 Comparison of (A) straight and (B) solid streams at tip.

13. Special Purpose Not often used
Cellar nozzles and Bresnan distributors:
Fight localized fires in basements when firefighters cannot make direct attack
Piercing nozzles originally designed to penetrate the skin of aircraft
Modified to pierce through building walls and floors
Water curtain nozzle
Sprays water to protect against heat exposure

14. (A)
(B)
Figure (A) Cellar nozzle and (B) Bresnan distributor.

15. Figure 11-13 Piercing nozzle.
Figure Water curtain nozzle.

16. Nozzle Operations Solid tip nozzles easy to operate
Nozzle size and tip selected to match desired flow
Carry smaller nozzle tips in pocket
Fog nozzles with rotating valves common for wildland firefighting
Gallonage and pattern adjustments detected in the dark because nozzle clicks at each position
Fog nozzles have more applications than smooth bore nozzles
Considered more effective

17. Operating Hoselines Chapter 10 covers:
Advancing hoselines, initial nozzle operation
Straightening the hose
Properly spacing firefighters on same side of line
Bleeding off air from hose and nozzle
Selecting proper pattern
Most hoselines operated from crouching or kneeling position
Lying, standing, or sitting positions also used

18. Small-Diameter Handlines
Typically 1½, 1¾, or 2 inches in diameter
Flow from 100 to over 250 gpm
When flowing at lower volumes, operated by one person
Larger volumes require two people
Fog and solid tip nozzles can be used for small lines
Small lines popular because of ease of mobility, number of personnel, extinguishing ability

19. Medium-Diameter Handlines
Medium-diameter hose for handlines:
2½-inch or 3-inch hose
Solid tip and fog nozzles
Flow from 165 to 325 gpm
2½-inch hose is standard size hoseline
Many departments use 1¾-inch and 2-inch for attack
Increased maneuverability
Large commercial structures or buildings with high fire loading require increased gpm flow of 2½-inch line
Require two or more personnel to operate

20. Master Stream Devices Master stream devices capable of 350 gpm
Main artillery of fire service
Used when large volumes of water required
Must be apparatus-mounted or secured properly
Require only one person to operate
Lack of mobility

21. Stream Application, Hydraulics, and Adverse Conditions
Applications of fire streams vary according to method of fire attack, conditions encountered
Including environmental factors and water supply
Fire streams must have proper pressure and flow
Firefighters must understand hydraulics
Improper hydraulic calculations are the leading cause of poor fire streams

22. Direct, Indirect, and Combination Attack
Direct fire attack
Aim the flow of water directly at the seat of the fire
Used on deep-seated fires that require penetration
Indirect fire attack
Apply a fog stream into a closed room
Convert water into steam to extinguish the fire
Combination attack
Typical attack in structural firefighting

23. Figure 11-20 Firefighter directly attacking a fire.

24. Figure Firefighter using indirect attack by applying water into room and then closing the door.

25. Figure One cubic foot of water in liquid form expands 1,700 times when converted to steam at 212°F.

26. Figure Firefighter using combination fire attack directing the stream from the ceiling to the fire with a circular, “Z” or “T” motion.

27. Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines
Hydraulics: study of fluid in motion
Pressure: force divided over an area
Flow: rate and quantity of water delivered
Friction loss: loss in pressure due to friction
Discharge pressure of a pump:
EP = NP + FL ± E + SA

28. Figure 11-27 Example for friction loss and engine pressure calculations.

29. Adverse Conditions Two types: natural and man-made Natural:
Wind and wind direction
Breaks up stream and deflects it from its target
Rain, snow, hail, tree branches, wires, etc. deflect and break up hose streams
Gravity and air friction:
Move closer to the target or to a better position

30. Types of Foam and Foam Systems
Class B foam: specially formulated concentrated liquid foaming agents
Creates a blanket that cools and smothers the fire
Seals in vapors
Class A foam: detergent or soap-based surfactants
Penetrate ordinary combustible materials
Keeps fuel wet and reduces its ability to burn

31. Foam Characteristics
Protein foam: natural protein materials with metallic salts
Fluoroprotein foam: improved protein foam with fluorinated surfactant added
Alcohol-resistant foam: contains a polymer
Forms a layer between burning surface and foam
Fluoroprotein film-forming foam (FFFP):
Combines protein with film-forming fluorosurfactants
Detergent-type foams: synthetic surfactants break surface tension of water

32. Classification of Fuels
Foams used for Class A and B fires
Specific considerations affect their use

33. Class A Piles of Class A materials extinguished using a wetting agent
Foamy water solution has the ability to cling to sides of objects
Used to protect homes in urban interface areas during wildland fires
Disadvantages:
Cost of equipment and agent, environmental effects
Fire investigation lab tests, difficult salvage operations

34. Class B Class B fuels: hydrocarbons and polar solvents Hydrocarbons:
Firefighters do not use foam
Hydrocarbons:
Examples: heating oil, gasoline, paraffin, asphalt
Not miscible; foam is best method to extinguish
Polar solvents:
Examples: alcohols, lacquer thinners, acetone
Normal foams break down when used on fires involving these mixtures
Special foams create a polymeric barrier

35. Figure 11-29 (A) AFFF applied on Class B fuel
Figure (A) AFFF applied on Class B fuel. Note the film barrier on the surface.

36. Figure Polar solvent or alcohol-type foam applied on Class B polar solvent fuel. Note the polymeric film barrier on the surface.

37. Application of Foam
Requires a device to proportion, meter, or mix foam concentrate into the water
Air added to foam solution
Eductor: common proportioner
Works on Venturi principle
Must have proper gpm flow, correct pressure, be clean, not have back-pressure situations
Compressed air foam systems (CAFS):
Concentrate in separate foam tank
Concentrate metered by microprocessor

38. Figure 11-33 Foam eductor using the venturi principle.

39. Bank-In Technique
Figure The bank-in technique of foam application.

40. Bank-Back Technique
Figure The bank-back technique of foam application.

41. Raindown Technique
Figure The raindown technique of foam application.

42. Fog Nozzles versus Foam Nozzles
Some nozzles combined all foam-making steps
Modern foam nozzles aspirate air and apply foam to the fuel
Air vents built into the nozzle
Designed for low and medium expansion
Recommended with protein and fluoroprotein foams
Fog nozzles can be used with foam
Clip-on foam nozzle adapters attach to the fog nozzle
Three techniques: bank-in, bounce-off, raindown

43. Nozzle and Foam Equipment Maintenance
Nozzles and foam appliances must be cleaned and maintained regularly
Follow manufacturer guidelines and department policies
Guidelines and policies should include:
Cleaning and maintenance schedule
Necessary skill level of firefighter
Documentation procedures
Replacement and repair process

44. Lessons Learned
Fire streams: water that leaves a nozzle and heads toward the target
Solid tip and fog nozzles
Nozzle should match fire conditions and department resources
Correct hydraulics calculations require understanding pressure and friction loss
When fuels not compatible with water, other agents are used
Foam requires special equipment