Kirks Fire Investigation Ch 4

Front 1

GASES

Flammable materials found in the gaseous form will burn when mixed with what?

Back 1

When mixed with the proper amount of air and properly ignited

Front 2

Does the flash point have an significance with gaseous form

Back 2

No

Front 3

Does boiling point have any significanace with gases forms

Back 3

No

Front 4

The flammable range of mixture with air

Back 4

Blank _____________Density and _______________and ___________________are important properties

Front 5

Liquids and there Vapor

Vapors from liquids are the materials that directly support what?

Back 5

the flame over a liquid fuel

Front 6

What are the important considerations to the liquid vapor combination?

Back 6

Vapor pressure, Flash point and to a lesser defree boling point.

Front 7

What are the critical properties of vapors themselves?

Back 7

Ignition temperature, range of flammable concentrations of vapor air mixtures and vapor densities

Front 8

Why are liquids themselves of little or no interest except as indicated for their production of flammable vapors, a process integral with combustion?

Back 8

Because they rarely burn

Front 9

Solids

Solids burn by direct combinatio of oxygen with their surface (glowing combustion) , as volatilized materials that have melted and vaporized, or as complex fuels that pyrolyze to form combustible gases and vapors and leave a noncombustible solid residue.

Reactive metals such as Magnesium, soduim, potassium, or ____________ or ______________ fuels such as charcoal burn only at their surface, as a flowing fire.

Back 9

Phosphorus or carbonaceous fuels

Front 10

Solids

If the vapors being pyrolyzed from common solid fuels are disregarded, most of the properties just mentioned do not apply to ___________

Back 10

Solids

Front 11

Solids

Solid fuels have no _________ _________ in the strict sense, no vapor density, no single ___________________.

Back 11

Flash point no single ignition temperature

Front 12

Solids

Have a _____________ _______________ range only when they are finely divided and stirred into air as a combustible dust suspension.

Back 12

Flammable mixture range

Front 13

Their physical properties that control their flammability are such factors as density, conductivity, and thermal capacity.

Back 13

Factors are density, conductivity, and thermal capacity

Front 14

Under some conditions the solids ____________ and ____________ will also influence their performance as fuels.

Back 14

Porosity and Melting point

Front 15

Vapor Pressure

Any _________________exposed to air will evaporate as molecules escape its surface.

Back 15

Liquid

Front 16

A liquid in a sealed system will create an equilibrium state where the vapor reaches saturation and there is no further evaporation.

Back 16

Called Saturated vapor pressure

Front 17

The partial atmospheric pressure exerted by the vapor at this stage is called the

Back 17

Saturated vapor pressure

Front 18

Saturated vapor pressure is most often measured in mmHg

Back 18

Atmospheric pressure is 760 mmHg is the direct measure of the bolatility of the liquid and is determined by the molecular weight and chemical structure of the liquid involved and the temperature.

Front 19

The higher the temperature the more liquid will evaporate and the higher the

Back 19

Vapor Pressure

Front 20

The lower the molecular weight, the higher the

Back 20

Vapor Pressure

Front 21

The vapor pressure is a fundamental physical property that has a great influence on the

Back 21

Flammability of liquid fuel

Front 22

When vapor pressure reaches 760mmHg the liquid is at its

Back 22

Boiling Point so the temperature at which that occurs is recorded as its boiling temperature.

Front 23

When temperture of a liquid fuel is such that its vapor pressure reaches the percentage of

Back 23

760 mmHg that is equivalent to the lower flammability limit of the fuel the fuel is said to be at its flash point.

Front 24

The vapor pressure is also dependent on the contour of the surface of the liquid. It is higher for a convex surface than for a flat surface at the same temperture. This is why an aerosol of small droplets or a liquid distributed on the fibers of a porous wick is easier to ignite then a pool of the same liquid

Back 24

Vapor pressure is also dependent on the contour of the surface of the liquid

Front 25

FLAMMABILITY EXPLOSIVE LIMITS

Mixtures of flammable gases or vapors with air will combust

Back 25

Only when they are within particular ranges of concentration.

Front 26

When a gas is present at a concentration below its LEL or LFL

Back 26

lower explosive limit or its Lower Flammability limit

Front 27

When a gas is present at a concentration below its LEL or LFL it is considered to be too

Back 27

Lean a mixture to burn and cannot be ignited

Front 28

When concentrations of gas are above its upper explosive limit UEL the fuel air mixture is to

Back 28

Rich to burn and will not ignite.

Front 29

Fuels such as hydrogen, carbon monoxide and carbon disulfide have very wide ranges within which flame will propagate to create an exploxion. Most fuels such as petroleum distillate hydrocarons show quite narrow limits of concentration.

Back 29

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Front 30

Natural gas

Back 30

Lower 4.5 upper 15 Ignition temp Min C 482-632 F 900-1,170

Front 31

Propane

Back 31

LEL 2.15 UEL 9.6 Ignition temp Min C 493-604 F 920-1,120

Front 32

Butane

Back 32

LEL 1.9 UEL 8.5 Ingnition temp Min C 482-538 F 900-1000

Front 33

Accetylene

Back 33

LEL 2.5 UEL 81 Ingnition temp Min C 305 F 581

Front 34

Hydrogen

Back 34

LEL 4 UEL 75 Ingnition temp Min C 500 F 932

Front 35

Ammonia

Back 35

LEL 16 UEL 25 Ingnition temp Min C 651 F 1204

Front 36

Carbon Monoxide

Back 36

LEl 12.5 UEL 74 ingnition temp Min C 609 F 1128

Front 37

Ethylene

Back 37

LEL 2.7 UEl 36 Ingnition temp Min C 490 F 914

Front 38

Ethylene Oxide

Back 38

LEL 3 UEL 100 Ingnition temp Min C 429 F 804

Front 39

Within a closed system if the mixture will not explode it will not ?

Back 39

Ignite

Front 40

Within a closed system if the mixture will not explode or ignite. For this reason the

Back 40

Explosive range and flammability range of a gas or vapor may be thought of as one and the same

Front 41

Flammability limits are ______________________ dependant

Back 41

Temperture dependant

Front 42

The highter the initial temperture

Back 42

The wider the range

Front 43

FLASH POINT

The flash point of a material is the ________________ temperature at which it produces a flammable vapor.

Back 43

Lowest

Front 44

At its flash point temperature the vapor pressure of the fuel 760 mm is equal to that fuel's _______________

Back 44

LLF lower limit of flammability

Front 45

The flash point of low octine gasoline produces a vapor that can be ignited at any temperature above -43C not that gasoline will spontaneously ignite at such an extremely low temperture. It requires what?

Back 45

Flame a small arc or other local source of heat.

Front 46

How do you test the flash point

Back 46

It is determined by placing a small sample of the fuel in the cup of a testing apparatus and heating or cooling it to the lowest temperature at which an arc or small pilot flame will cause a little flash to occur over the surface of the liquid.

Front 47

Types of Flash point testers

Back 47

Pensky Martens, Cleveland adn Tag

Front 48

What handbook can you find Flash Point Test ?

Back 48

NFPA Fire Protection handbood

Front 49

Flame Point/Fire Point

What is the Flame point or Fire point at which liquid produces a vapor that can sutain a contiuous flame

Back 49

it is the lowest temperature. (rather than the instanteous flash of the flash point.

Front 50

Ignition Temperature

It is important to all considerations of fire.

It is sometimes refered to as

Back 50

AIT Autoignition temperature or spontaneous ignition temperture SIT

Front 51

Ignition Temperature is the temperture at which a fuel will ignite ______________________________________________________________________________________________________________

Back 51

on its own without any additional source of ignition.

Front 52

Some Common Ignitable Liquids minimum spontaneous ignition temperature

Acetone

Back 52

Acetone C 465 F 869

Front 53

Gasoline low octane

Back 53

Gasoline low octane C 280 F 536

Front 54

Gasoline High Octane

Back 54

Gasoline High Octane C 456 F 853

Front 55

Turpentine (Spirits)

Back 55

Turpentine C 253 F 488

Front 56

AIT Auto ignition Temperature

How is AIT measured

Back 56

It is measured using the minimum temperature by a particular lab technique and is dependent on size shape and even surface material and texture of the confinement vessel used in the test apparatus.

Front 57

What is the most commonly used method used to determine minimum ignition temperature ?

Back 57

ASTM E659

Front 58

IGNITION ENERGY

Every Fuel Gas or vapor has a __________________ ignition energy

Back 58

Minimum

Front 59

Ignition energy it the amount of energy that must be transferred to fuel to trigger the first _______________

Back 59

Oxidation

Front 60

What are the four required conditions for there to be ignition of a vapor air mixture.

Back 60

1. It must have adequate energy
2. The must be within its flammability range
3. It must have contact between the source and the fuel while it is in that range
4. The contact must be of sufficient duration for enough energy to be transferred from the source to the fuel

Front 61

Do all 4 conditions have to be met for there to be ignition of a vapor

Back 61

Yes

Front 62

BOILING POINTS

As a rule the low boiling point will usually have a low _______________ ________________

Back 62

Flash Point

Front 63

VAPOR DENSITY

The fundamental property of a vapor that predicts its behavior when released in air is its

Back 63

Vapor Density

Front 64

Vapor density

Gas or vapors with a vapor density greater than 1.0 are heavier than air and tend to settle through the air into which they are released until they encounter an obstuction such as a floor. after which they tend to spread at this level like liquids. Vapors lighter than air tend to ____________through the air until an obstruction such as a ceiling. They spread at the high level

Back 64

Rise

Front 65

Fuel Vapor

When a fuel vapor is heaver than air (V.D.=1.0) its deffusion rate will be much __________

Back 65

Less than when its density is close to 1.0. The diffusion of a vapor is a very slow process

Front 66

Methane is lighter than air and tends to ________

Back 66

rise in a room

Front 67

HEAT OF COMBUSTION (HEAT OUTPUT)

Real worl maximum open flame temperatures of nearly all normal fuels burning in turbulent diffustion flames is about 900 C

Back 67

1,700 F

Front 68

HEATS OF COMBUSTION AND FLAME TEMPERATURES OF SOME FUELS

Acetylene

Back 68

Acteylene2,325

Front 69

Butane

Back 69

Butane 1,895

Front 70

Charcoal

Back 70

2,200

Front 71

Ethane

Back 71

Ethane 1,895

Front 72

Methane

Back 72

Methane 1,875

Front 73

Propane

Back 73

Propane 1,925

Front 74

Wood

Back 74

Wood 1,590

Front 75

HYDROCARBON FUELS

The most important fuels of fire investigtion are the Hydrocarbons They range from

Back 75

Light gas methane to much heavier compounds including oils and asphalts.

Front 76

Hydrocarbons Liquified Petroleum Gas (LPG)

Used where natural gas isnt avalible. it is a mixture of propane and N-butane.for the most part it can be considered LPG the same as propane in its physical and _____________________ _____________________

Back 76

Combustion properties

Front 77

Hydrocarbons

Gasoline the most important fuel of petroleum origin is a mixture of volatile low boiling and midrange _________________

Back 77

Hydrocarbons

Front 78

Gasoline contains hydrocarbon compounds with boiling points between approx

Back 78

32 C 90 F and 205 C and 400 F

Front 79

Modern automotive gasoline contains more then

Back 79

150 hydrocarbons

Front 80

Ignitable liquids considered either flammable or combustible includes an intermediate range called

Back 80

Medium petroleum distillates having a boiling point between 215 C or 250 C to 400 F

Front 81

Medium petroleum distillates having a boiling point between 215 C or 250 C to 400 F

Many household products and commercial products fall into this class paint thinners mineral spirits some charcoal starters and _____________ ____________

Back 81

Insect sprays.

Front 82

Kerosene and heavier petroleum distillates have long been of sinificance in the setting of deliberate fires. Why?

Back 82

Because their lower volatility presents less hazard to the user than does gasoline.

Front 83

Name a nonhydrocarbon Liquid fuel

Back 83

Methyl alcohol is widely used in spirit duplicaing machines as an alternative motor fuel and as a thinner for shellacs.

Ethyl Alcohol

Front 84

Ethyl Alcohol

in reagent 190 proff or high proof beverage from 85 or higher can be used to start fire even though its heat output is not very high

Back 84

Ethyl Alcohol can be used to start fires 190 to 85 proof

Front 85

Isoppropyl (Rubbing Alcohol is flammable at the concentrations packaged fro retailed use. All the sipler slcohols can provide fuel for the __________________ ______

Back 85

Incendiary fires

Front 86

Why are fires that involve Isopropyl (Rubbing Alcohol) hard to detect?

Back 86

Because their extreme volatility and water solubility.

Front 87

Combustion of Liquid Fuels

When an ignitable liquid is poured or pilled on a surface it must be remembered that only its _____________ are actually combusting

Back 87

Vapors

Front 88

Raw wood or concrete will allow some penetration 2 to 3 millimeters or so with a proportional reduction in the ______ _______ _______ ________

Back 88

Of the pool.

Front 89

Carpets or other porous sufaces allow _______ _______

Back 89

Very deep penetration

Front 90

The resulting pools of carpets and other porous sufaces allow what size pools to form?

Back 90

Very small

Front 91

During the burning of a liquid pool fire the temperature of the surface beneath it can protect it bexause the temperature cannot exceed the __________ ______________

Back 91

Boiling Point of the liquid.

Front 92

For a low boiling point fuel like Methyl Alcohol the trmperature of the floor under the pool will not exceed about 64 C 147 F which is the __________ ____________ of Methyl Alcohol

Back 92

Boiling Point

Front 93

Explain the mechanism of why some fuels produce halo type burns and others scorch and char the floor more extensively?

Back 93

Because they are so shallow free standing pools of ignitable liquidsburn away quickly with the cracks or crevices localized burning can take place for longer periods of time.

Front 94

What would occur with extra ventilation added to the pool fire?

Back 94

With extra ventilation added it can draw through these cracks and severe but localized floor damage can result

Front 95

Flammable Liquids are all those that have a flash point below 100 F 37.8 C NFPA Class 1
Class 1A and 1B liquids having flash points below room temperature 73 F 22.8 C

Combustible liquids are those with a flash point above 100 F 37.8 C

Classes II flash point between 100 and 140 F 37.8 C and 60 C

Class III flash point above 140 F 60 C

Class IIIA flash point 140 F and 200 F

Class IIB flash point between 32 and 60 C

Back 95

CLASS I 100 F

CLASS IA AND IB 73 F

CLASS III 140 F

CLASS IIIA 140 f AND 200 f

CLASS IIB 32 AND 60c

Front 96

Ignitable liquids are a category of liquid fuels that includes both

Back 96

Flammable and combustible liquids

Front 97

GAS LINES

not normally represent a source of ignition they do represent a source of readily ignitable fuel. When does gas become a hazard?

Back 97

It becomes a hazard when the gas mixes with air it becomes flammable then making it combustible or explosive as a mixture.

Front 98

NATURAL GAS

Natureal Gas is piped underground via pipelines that may be pressurized to as high as

Back 98

1200 PSI they operate at typical pressures of about 60 PSI but may be up to 150 PSI.

Front 99

Can you use Cast iron for a natural gas line?

Back 99

No

Front 100

Failure from Heat

A gas line if falure occurs will produce a blowtourch effect and will display burning where

Back 100

to the front of the opening

Front 101

Fluid filled containers

Fluid filled containers failure due to the over pressure caused by extreme heating is often called

Back 101

BLEVE (Boiling liquid, expanding vapor explosion.

Front 102

Chapter 4 summary

Flammable gases and liquids are common fuels in accidental structrue fires and constitute a convenient source of fuel for a very high percentage of ____________ fires

Back 102

Incendary fires

Front 103

A fires environment is a complex one and the ____________ ______ _______________ of the heat produced may have dramatic effects on the physical and chemical properties of the fuels present.

Back 103

Intensity and duration of the heat