Nozzles, Fire Streams, and Foam

Objectives (1 of 5) Define a fire stream. Identify the purposes of a fire stream. Identify the various types of fire streams. Identify the types of nozzles. Explain the pattern and use of each type of nozzle.

Objectives (2 of 5) Demonstrate the operations of the various types of nozzles. Explain the operation and characteristics of various sizes of fire streams. Explain the reach and application of various sizes of fire streams. Identify the three types of fire attack.

Objectives (3 of 5) Explain the factors in choosing the type of fire attack. Identify and explain the principles of hydraulics relating to fire streams. Define and explain friction loss. Define and explain nozzle pressures and reactions.

Objectives (4 of 5) Define and explain elevation as a factor in fire streams. Explain adverse factors in operations of fire streams. Explain the selection factors for fire streams in fire operations.

Objectives (5 of 5) Define foam. Identify the types of foam. Explain the principles of foam for fire suppression. Explain the operation of foam-making equipment.

Introduction Fires are usually extinguished using water to cool the heat produced. Foam is used to extinguish fuels where water is ineffective. Water and foam are delivered using nozzles. Selection of the proper nozzle is important to successfully fight the fire.

Definition of Fire Streams A fire stream is water or other agent as it leaves the nozzle toward a target. Fire streams must be properly developed and aimed. Poor streams allow the fire to burn. A proper stream has sufficient volume, pressure, direction, and reaches the target. Firefighters need to understand fire streams and their application.

Nozzles (1 of 2) Nozzles are appliances to apply water. There are two basic types of nozzles. Solid stream nozzle Fog nozzle Combination nozzles can deliver both patterns. It is important to be aware of advantages and disadvantages of both.

Nozzles (2 of 2) Nozzle selection factors Nozzle pressure Nozzle flow Nozzle reach Nozzle reaction Stream shape

Stream Patterns

Solid Tip or Stream (1 of 2) Delivers an unbroken or solid stream of water. Delivers water as a solid mass. Solid mass breaks the further the water travels. Flow is a factor of the tip size. Excessive or reduced nozzle pressures have adverse effects on stream performance.

Solid Tip or Stream (2 of 2) Hand line tips are from 3⁄4” to 1¼” at 50 psi. Master stream tips are 1” and larger at 80 psi. Hand lines can reach over 70’ and master streams about 100’. Have less effect on a room’s thermal balance. Have good penetration.

Solid Tips

Fog Nozzles (1 of 4) Nozzles deliver a fixed or combination pattern. Fixed spray patterns are of the impinging design. Constant or set volume nozzles only allow pattern adjustment.

Fog Nozzles (2 of 4) Variable combination fog nozzle patterns vary from straight stream to wide fog. Adjustable nozzles allow for selection of flow and pattern.

Fog Nozzles (3 of 4) Operate from 50 to 100 psi Provide good reach that varies with pattern Provide good penetration Produce more steam Can be used to assist in horizontal ventilation

Fog Nozzles (4 of 4)

Fog Nozzle Ventilation

Straight Stream Pattern creates a hollow type stream. As stream passes through nozzle baffle, air goes into the stream reducing its reach. Newer nozzle designs have compensated for this.

Special Purpose Nozzle (1 of 2) These were developed for use in limited types of situations. Cellar nozzles and Bresnan distributors are effective for basement and cellar fires. Piercing nozzles were designed to penetrate aircraft skin and building walls and floors. Water curtain nozzle is designed to spray water to protect against exposures to heat.

Special Purpose Nozzle (2 of 2)

Playpipes and Shutoffs Shutoff at the nozzle places flow control with nozzleperson. Shutoff is opened by pulling back on the lever.

Nozzle Operations Solid tips are screwed on and off. Fog nozzles are either lever-type open/close shutoff or rotating type. Fog pattern can be adjusted by rotating the nozzle barrel. Nozzles with variable gallonage have an additional rotating ring on the collar. Nozzle clicks when adjustments are made.

Operating Hoselines Most operated from a crouching or kneeling position Small-diameter hand lines Medium-diameter hand lines Master stream devices

Hoseline Operations

Stream Application (1 of 3) Fire stream application depends on fire attack method and conditions encountered. Fire stream must have proper pressure and flow. An understanding of hydraulics is needed to assure proper pressure and flow.

Stream Application (2 of 3) Direct fire attack aims the flow of water directly at the seat of the fire. Indirect fire attack is used by converting water into steam in a closed room. Quantity of water applied is amount needed for total conversion of steam to fill a room. Indirect fire attack should not be used with people in the room.

Stream Application (3 of 3) Combination attack uses a blend of direct and indirect fire attacks. For a combination attack, water is aimed at the ceiling and then rotated. Ventilation with this attack controls the flow of fire gases and steam.

Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines (1 of 5) Hydraulics is the study of fluids at rest and in motion. Fire streams must have sufficient volume and pressure. Pressure is required to lift, push, or move water. Pressure is force divided over an area.

Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines (2 of 5) Force is a measurement of weight. Water weighs 62.4 pounds per cubic foot, creating a force of 62.4 pounds. Atmospheric pressure is 14.7 psi at sea level. Gauge pressure measures pressure minus atmospheric pressure.

Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines (3 of 5) Vacuum (negative) pressure is the measurement of pressure less than atmospheric pressure. Apparatus used for drafting uses a compound gauge to measure vacuum pressure. Head pressure measures pressure at the bottom of a column of water in feet. Velocity pressure is the pressure in a hose as it leaves the nozzle.

Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines (4 of 5) Flow is the rate and quantity of water delivered. Required flow is the amount of water required to extinguish the fire. Available flow is the amount of water that can be moved to extinguish the fire. Discharge flow is the amount of water flowing from the discharge side of the pump.

Basic Hydraulics, Friction Loss, and Pressure Losses in Hoselines (5 of 5) Water flow can be determined using a flow meter or pressure gauge. When flow stops, the system is equalized at the highest pressure in the system. A sudden stop of water can create a water hammer or pressure surge. Discharge pressure of a pump: EP = NP+ FL± E + SA

Calculating Friction Loss and Engine Pressure

Adverse Conditions That Affect Fire Streams Major natural factor is wind and wind direction. Gravity and air friction are also natural factors. Factors cannot be removed, but bringing stream closer to the target reduces effects.

Types of Foam and Foam Systems Foam is an aggregate of gas-filled bubbles formed from aqueous solutions of specially formulated concentrated liquid foaming agents. Foam concentrate is mixed with water forming a solution to which air is added allowing foam to float over flammable liquids and extinguish them. Class A foam solutions are detergent or soap-based surfactants.

Summary Fire streams leave a nozzle and head toward a target. Two main types of nozzles are solid stream and fog nozzles. It is important to understand basic hydraulics. Foam application requires special equipment and unique application techniques.