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Nozzles and Fire Streams 1. Introduction Fires usually extinguished by water Water delivered using nozzles and fire streams Nozzle selection important.

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Presentation on theme: "Nozzles and Fire Streams 1. Introduction Fires usually extinguished by water Water delivered using nozzles and fire streams Nozzle selection important."— Presentation transcript:

1 Nozzles and Fire Streams 1

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

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 3

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

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

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 6

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

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

9 Parts of a fog nozzle. 9

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. 10

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

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 12

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

14 Piercing nozzle.Water curtain nozzle. 14

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 15

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 16

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 17

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 18

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 19

20 Direct, Indirect, and Combination Attack Direct fire attack Indirect fire attack Combination attack 20

21 Firefighter directly attacking a fire. 21

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

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 23

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. 24

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. 25

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

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

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

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 29

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