pfd - firestreams

8/9/2019 PFD - firestreams

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Basic FirefighterFire Streams

Michael Corsello

Peyton Fire


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Fire StreamsA stream of fire extinguishing agent

from the time it leaves a hose andnozzle until it arrives at it desiredlocation


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Fire Streams

A fire stream is composed of 4

primary elements:

1. Pump

2. Hose

3. Nozzle

4. Water


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Fire StreamsWater

The primary extinguishing agent

Cheap / plentifulMultiple states (liquid, solid, gas)

Expands to 1700 times its original sizewhen converted to steam

Occupies 1700 times its original volume

Increases surface area greatly, greatlyimproving its heat absorption rate


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Fire StreamsPressure loss / gain

Gravity loss / gain

1 atm = 14.7 psi

33ft column of water exerts 1 atm of force

Every 33 ft of elevation gain = 14.7 psi loss

Every 33 ft of elevation loss = 14.7 psi gain

Nozzle lower than source = greater pressure

Nozzle higher than source = less pressure


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Fire StreamsPressure loss / gain

Friction lossThe resistance of flow through a hose caused by bends

in the line, surface flow, deformities, etc; are collectivelyknown as friction loss

Larger hoses experience less friction loss than smallerhoses

The longer the distance, the greater the loss

Avoid sharp bends in hosesUse the shortest lines possible

Use larger hoses for longer runs (or siamese appliances)

Keep hoses in good condition


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Fire StreamsWater Hammer

Sudden reduction in the rate of flow of water

through a hose or pipe results in a transfer ofkinetic energy to the surrounding area hose,fittings, pumps, etc.

Water hammer can be heard as a sudden, sharpclank.

Water hammer can cause serious damage to allparts of the system


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Fire Streams


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Fire StreamsFire Stream Types

Low-volume streams

Less than 40gpm (i.e. booster lines)Handline streams

40-350gpm 1-3in lines

Master streams

Over 350gpm

fed by multiple 2 or 3in linesor by LDH lines these are large-volumestreams


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Fire StreamsFire Stream Patterns

Solid Stream

Fixed, open orifice (pressure jet nozzle)Operating pressure 50psi hand, 80psi master

Long range, small surface area indirect attack

Broken Stream

Stream broken into coarse droplets

Operate at greater pressures, have moderate distance,larger surface areas suitible for direct attack


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Fire StreamsFire Stream Patterns

Fog Stream

Stream broken into extremely small dropletsGenerally, nozzles are capable of varying widths ofpattern

Very short distance

LARGE surface area

Direct attacks

Cause much thermal imbalance

May cause excessive water damage


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Fire StreamsEach stream pattern has distinct advantages

Smaller droplets provide better surface area and

heat absorption, but have little resistance to

wind

Larger droplets have better distance, at the cost

of heat absorbing surface area


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Fire Streams


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Fire StreamsRemember

Safety First

pfd - firestreams

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