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Chapter 11

Chapter 11 . Nozzles and Fire Streams. Introduction. Fires usually extinguished by water Water delivered using nozzles and fire streams Nozzle selection important. Definition of Fire Stream. Fire stream Four elements affect stream: Pump Water Hose Nozzle Proper stream

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Chapter 11

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  1. Chapter 11 Nozzles and Fire Streams

  2. Introduction • Fires usually extinguished by water • Water delivered using nozzles and fire streams • Nozzle selection important

  3. Definition of Fire Stream • Fire stream • Four elements affect stream: • Pump • Water • Hose • Nozzle • Proper stream • Sufficient volume • Pressure • Direction to reach its target

  4. Nozzles • Nozzles: • Solid stream and fog • Combination nozzles: • Straight stream or adjustable spray • Nozzle pressure • Nozzle flow • Nozzle reach • Stream shape • Nozzle reaction

  5. Nozzles showing the stream shape for straight, solid, and wide pattern streams.

  6. Solid Tip or Stream • Deliver unbroken stream of water • Solid stream nozzle • 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

  7. Fog Nozzles • Deliver fixed or variable spray pattern • Fog provides better heat absorption • Hydraulic ventilation

  8. Variable combination fog nozzle patterns. From top to bottom: straight stream, narrow fog, and wide fog.

  9. Parts of a fog nozzle.

  10. Straight Stream • Creates a hollow type stream • 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.

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

  12. Special Purpose • Not often used • Cellar nozzles and Bresnan distributors • Piercing nozzles • Modified to pierce through building walls and floors • Water curtain nozzle • Sprays water to protect against heat exposure

  13. (B) (A) (A) Cellar nozzle and (B) Bresnan distributor.

  14. Piercing nozzle. Water curtain nozzle.

  15. Nozzle Operations • Solid tip nozzles easy to operate • Nozzle size and tip selection • Fog nozzles with rotating valves • Gallonage and pattern adjustments • Fog nozzles have more applications than smooth bore nozzles. • Review Chapter 10. • Most hoselines operated from crouching or kneeling position

  16. Small-Diameter Handlines • Typically 38, 45, or 50 mm (1½, 1¾, or 2 inches) in diameter • Flow from 400 to over 1,000 L/min (100 to over 250 gpm) • When flowing at lower volumes, operated by one person • Fog and solid tip nozzles can be used for small lines. • Ease of mobility • Number of personnel • Extinguishing ability

  17. Medium-Diameter Handlines • 65 to 77 mm (2½-inch or 3-inch hose) Solid tip and fog nozzles • Flow from 625 to 1,200 L/min (165 to 325 gpm ) • 65 mm (2½-inch) hose is standard size hoseline • Large commercial structures • Require two or more personnel to operate

  18. Master Stream Devices • Capable of 1,400 L/min(350 gpm) • Artillery of fire service • Large volumes of water • Apparatus-mounted or secured properly • One person to operate • Lack of mobility

  19. Stream Application, Hydraulics, and Adverse Conditions • Applications of fire streams vary • Method of fire attack • Conditions encountered • Including environmental factors • Water supply • Proper pressure and flow • Hydraulics • Improper hydraulic calculations are the leading cause of poor fire streams

  20. Direct, Indirect, andCombination Attack • Direct fire attack • Indirect fire attack • Combination attack

  21. Firefighter directly attacking a fire.

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

  23. Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines • Hydraulics • Pressure • Flow • Moving water through hoselines, nozzles and appliances requires forces that act positively and negatively to achieve flow. • Mass • Pressure

  24. Friction Loss The loss of energy from the turbulence, or rubbing, of the moving water through the hose • Pump operator compensates for friction loss by increasing the pump pressure for the correct pressure to the nozzle.

  25. Friction Loss Principles • Friction loss is based on four principles: • Friction loss varies directly with the length of the hose if all other variables are held constant. • Friction loss varies approximately with the square of the flow. • When the flow remains constant, friction loss varies inversely with the hose diameter. • For any given velocity, the friction loss will be about the same regardless of the water pressure.

  26. Pump Discharge Pressure • Discharge pressure of a pump: PDP = NP + FL ± E + A • Pump Discharge Pressure • Nozzle Pressure • Friction Loss • Elevation • Appliance loss

  27. Example for friction loss and pump discharge pressure calculations.

  28. Adverse Conditions • Two types: natural and man-made • Natural • Wind and wind direction • Rain, snow, hail, tree branches, wires • Gravity and air friction

  29. Lessons Learned • Fire streams • Solid tip and fog nozzles • Nozzle should match fire conditions and department resources • Correct hydraulics calculations • Effective use of nozzles and fire streams on the fireground

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