Fire Expo Los Ion Principles

8/6/2019 Fire Expo Los Ion Principles

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Product Safety

Technical Seminar

-T.A. Crawford, P. Eng. Created: October 19, 2000

Revised: January 30, 2003


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Principles of Area Classification


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ExplosionExplosion

Bang or Muffled Whoosh


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Release of Gas

and/or Liquid

No Ignition

Immediate

IgnitionFire

Formation

of

Combustible

Fuel-Air

Cloud

(premixed)

Ignition

Delayed

Gas

Explosion

No

Damage

Damage to

personnel and

Material

Fire

Fire and BLEVE

(domino effects)

Typical Consequences of Accidental releases of

Combustible Gas or Evaporating Liquid into the

Atmosphere


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General Information on Explosions

Commonly involve toxic substances.

Usually result in damaging fires.

Often used in industry for constructive

purposes.

Pose significant hazards to workers:

Detonation, Deflagation.


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Detonation

A detonation wave is a supersonic (relative to the speed of

sound in the unburned gas ahead of the wave) combustion

wave. The shock wave and the combustion wave are in thiscase coupled. In a fuel-air cloud a detonation wave will

propagate at a velocity of 1500-2000 m/s and the peak

pressure is typically 15 to 20 bar.


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Deflagration

The deflagration mode of flame propagation is the most

common. A deflagration propagates at subsonic speed

relative to the unburned gas, typical flame speeds (I.e.relative to a stationary observer) are from the order of 1 to

1000 m/s.The explosion pressure may reach values of

several barg, depending on the flame speed.


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Trouble in the AtmosphereTrouble in the Atmosphere 3 States of a substance- Solids, Liquids and Gases.

Solids can cause problems where they are able to engulf a rescuer but

are not common consideration in terms of atmospheric contamination.

Liquids can often be the catalyst for or direct cause of dangerous

fumes.

Gases can be Toxic, flammable or explosive, light or heavy.

An atmosphere could be 100% safe until you walk through one

particular section and cause a rapid change in circumstances.

Sample frequently in all parts of space-ground, middle and top.


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What Oxygen Level Is Safe?What Oxygen Level Is Safe?14%, 16%, 18.5%, 19.5%, 20.8%, 21.5%


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Change is a concern: 14

%, 16

%, 18

.5

%, 19.5

%, 20.8

%, 21.5

%

A 1.5% drop in Oxygen means that a

whopping 7.5% of something else has

gotten into that space.


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The Effects of Oxygen at different partial pressures ( from ANSI Z82.2-1992)

%O2 at

Sea

Level

Atmospheric

Pressure

(mmHg)

Ambient

Atmospheric ppO2

(mmHg)

Upper

Lung

(mmHg)

Alveolar

(mmHg)Equivalent

Altitude

(ft.)

Effects

20.9 760 159 149 110 Sea Level Normal

19.0 689 145 135 95 2,500 Some adverse physiological effects occur, but they are

unnoticeable.

16.0 581 121 114 70 7,500 Increased pulse and breathing rate. Impaired thinking and attention.

Reduced coordination.

14.0 532 110 100 60 10,000 Abnormal fatigue upon exertion. Emotional upset. Faulty

coordination. Poor judgment.

12.5 450 96 85 48 14,000 Very poor judgment and coordination. Impaired respiration that

may cause permanent heart damage. Nausea and vomiting.


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Solid Materials

Phosphorus (white) 60C

Peat 230 C

Sulphur 250 C

Spruce Wood 280 C

Brown Coal 250280 C

Hard Coal 330440 C

Sugar 410 C

Tar 500 C

Rye Flour 500 C


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Flammable and Combustible

Liquids National Fire Protection Association.

Applies to the handling , storage, and use of flammable

and combustible liquids with a flash point below 200F. Two primary hazards associated with flammable and

combustible liquids are explosion and fire.

Standards addresses primary concerns of design and

construction, ventilation, ignition sources and storage. OSHAs specific requirements.


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Boiling PointThe Boiling Point of a liquid at a pressure of 14.7 pounds/Square inch

absolute (psia.) 760mm of Hg.

At temperatures above the boiling point, the pressure of the atmosphere can

no longer hold the liquid in the liquid state and bubbles begin to form. Thelower the boiling point, the greater the vapour pressure at normal ambient

temperatures and consequently the greater the fire risk.


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Flash Point The minimum temperature at which a liquid

gives off vapour within a test vessel in

sufficient concentration to form an ignitable

mixture with air near the surface of the

liquid.

The flash point is normally an indication ofsusceptibility to ignition. The expression

low flash-high hazard applies.


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Combustible LiquidCombustible Liquid

Any liquid having a flash point at or

above 100F (37.8C.)


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Flammable LiquidFlammable Liquid

Any liquid having a flash pointbelow

100F (37.8C) or higher , the total of

which make up 99% or more the total

volume of the mixture.


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Flash Point of a Few Common Liquids

Liquid Flash Point (rC)

Propane -104

Butane -60

Ethyl Ether -45

Gasoline -43

Carbon Disulphide -30

Acetone -18

Benzene -11Methyl Ethyl Keytone (MEK) -9

Heptane -4

Toluene 4

Methyl Alcohol 11

Ethyl Alcohol 12

Propyl Alcohol 15

Jet Fuel (JP4) 18

Turpentine 35

Polyester Resin 38

Diesel Fuel 40

Kerosene 51.6

Fuel Oil 80

Ethyl Glycol 111

Lubricating Oil 149

Corn Oil 254


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ClassesClasses ofFlammable and Combustible Liquids as Defined in 29CFR1910.106

200

140

100

73

F

LA

S

H

P

O

I

N

T

(F)

BOILING POINT (F)

100

IA IB

IC

FLAMMABLE(Flash Point


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Vapour PressureVapour Pressure

Measure of a liquids propensity to

evaporate. The higher the vapour pressure,

the more volatile the liquid and, thus, the

more readily the liquid gives off vapours.


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Types of Reaction

Flames: Exothermic chemical oxidation reactions in thegaseous state. The oxidant usually is atmospheric air, which

is supported by diffusion from the outside of the flame.Hence, the oxidation proceeds relatively slow.


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Types of Reaction

Explosions: Occur if the flammable substance has beenpremixed with the oxidant. It is possible in the gaseous,

liquid or solid state. The chemical reaction proceeds muchmore violently, as temperatures rises more quickly. The

initial pressure may increase tenfold.


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Explosive LimitsExplosive LimitsThe explosive range ill iden hen the initial temperature is increasing. hanges in initial

pressure ill or hydrocarbons in air not change the LEL signi icantly, but the EL ill increase.

25C Temperature0

&

100&

'

uel Concentration Explosive(

ixt) re0

) toig1 itio1

2

EL

LEL


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Explosive Limits (Air/ Oxygen mixtures)

Chemical Explosive limit in Air Explosive Limit in

oxygen

Ammonia 15.50 27.00 13.50 79.00

Carbon Monoxide 12.50 74.20 15.50 93.90

Hydrogen 4.00 74.20 4.65 93.90

Methane 5.00 15.00 5.40 59.20

Diethyl ether 1.85 36.50 2.10 82.00

Propylene 2.00 11.10 2.10 52.80


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Gas Explosion

Process where combustion of a premixed

gas cloud, i.e. fuel-air or fuel/oxidizer is

causing a rapid increase in pressure.


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Pressure Piling

Ig itio

Flame

Fro t

r e

ases

she

hea

ot

Tur ule t

ases

Emerge

ast

arge

ressure

rop

Causi g

Cooli g

Internal xplosion ccurring at Centre o nclosure


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150

100

50

0 0.1 0.2 0.3 0.4 0.5

Time-Seconds

2nd Enclosure

1st Enclosure

Pressure Traces for Two

enclosure connected by Conduit

100

80

60

40

20

0 0.2 0.4 0.6 0.8 1.0

Time-Seconds

Explosion pressure Traces for

Ignition by Switch Arc

Pressure Piling can

increase the explosion

pressure by up to 3times in an explosion-

proof enclosure

Gas or Vapour EP (PSI) TPP (MS)

Acetylene 149 14

Ethylene 129 25

Propane 125 46

Methane 104 70

Hydrogen 102 7


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Effect of Temperature on Explosion Pressure

-50 -40 -30 -20 -10 0 10 20 30 40 50

Temperature (C)

600

700

800

900

1000

9.8% Methane-Air

Single Chamber

Testing at low

temperature found that

Pressure increased in

direct proportion to the

decrease in

temperature.

As temperature

decreases, there is

more gas and air in a

given volume.


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Inertization

Means to reduce the oxygen

concentration to a safe levelLOC, Cmax(O2)


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Inertization(figures depend on pressure and temperature)

Examples Cmax(O2) [% by moles]

Inert gas N2 CO2

Hydrogen 5.0 5.0

Petrol ~11.8 ~14.5

Methane 12.1 14.6

Benzene 11.2 13.9


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Inertization


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0 10 20 30 40 50 60 70 80 90 100

0.1

1.0

MIE

Intrinsically Safe Zone (Hydrogen)

Propane

Hydrogen

Concentration in Volume (%)

Increasing the initial temperature of a flammable or combustible mixture will decrease the

amount of energy required to cause an ignition. Temperature variation can also change

the concentration of flammable materials in the mixture.

Oxygen enrichment decreases the energy necessary for an ignition.

MIE is inversely proportional to pressure squared. When examining a situation where the

gas mixture is not at atmospheric pressure, one must consider whether a flammable

mixture exists under higher-pressure conditions. When the mixture is at high pressure

many flammable materials condense.

Ignition Curves

and Minimum

Ignition Energy

Ethylene

Flammable Range


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10-2

10-3

10-4

10-5

10-6

0 10 20 30 40

Atmospheric Air

Oxygen

Ether Vapour (%)

The curve corresponding to atmospheric air is very narrow. This means that as soon

as you move slightly outside the most easily ignited mixture ( 6% ether), the necessary

energy is much higher. It is therefore possible only in a very small region to cause the

vapour to ignite by a 0.2 mJ spark. On the other hand, somewhere between thesurface of the mixture, where the mixture is to rich, to perhaps a couple of feet away,

where the mixture is too lean, well find the most volatile mixture. However, for a

concentration of approximately 16% ether vapour in pure oxygen, it takes only about

1 QJ to start an explosion.

If we have a mixture of oxygen anddiethyl ether, the molecules may

react with each other if they get into

a close-enough encounter, forming

water and carbon monoxide. For this

to happen, a certain amount of

energy has to be delivered in a

sufficient volume and in a

sufficiently short time.

Ignition Energy for Diethylether Mixtures


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Causes of explosions Heavy concentrations of fuel.

Highly heated flammable gas mixture.

Presence of a strong oxidizer.

Increase in pressure.

Detonation charge. Catalyst near reactive substance.


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Ignition Sources Electrical arcs

Electrical sparks

Flames

Hot surfaces

Static electricity

Mechanical impact

Mechanical friction

Compression ignition

Ionizing radiation

Acoustic energy

Electromagnetic

radiation includingoptical frequencies


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Common sources of releaseCommon sources of release

Packing seals on pumps, control

valves and similar devices.

Stems of valves that are

frequently operated. Drains and overflows.

Vents for tanks containing

flammable liquids.

Sampling points. Pressure relieving devices.

Filter presses, ovens, dryers and

spraying areas.

Bottom unloading tanks with

hoses having non-permanentconnections.

Freshly mined coal.

Fueling locations for vehicles

and aircraft.

Loading and unloadinglocations for tankers.


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Environmental conditions Affecting Classification

Elevation of the source of release.

Indoor locations without adequate ventilation.

Indoor locations with adequate ventilation-normally 6changes of air per hour.

Outdoor locations with restricted ventilation.

Outdoor locations with unrestricted ventilation.

Below grade locations with a heavier-than-air gas orvapour.

Covered outdoor locations with a lighter-than-air gas.


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Properties Affecting the Explosion HazardProperties Affecting the Explosion Hazard

Flash point.

Vapour density (molecular weight.)

Boiling point (volatility.)

Handling temperature.

Auto ignition temperature.

Ease of ignition (by spark or flame.)


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Classification Considerations The likelihood that the explosive gas atmosphere

is present when the equipment is operating.

The ignition-related properties of the explosivegas atmosphere.

The maximum surface temperature of the

equipment under normal operating conditions; and

The protection method(s) used by the equipment

to prevent ignition of the surrounding atmosphere.


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ClassesHazardous Location

Hazardous location means premises, buildings, or parts thereof in which there exists the hazard of fire or

explosion due to the fact that:

(a) Highly flammable gases, flammable liquids, mixtures, or other highly flammable substances aremanufactured or used or stored in other than original containers;

(b) Combustible dust or flyings are likely to be present in quantities sufficient to produce an explosive orcombustible mixture or it is impracticable to prevent such dust or flyings from collecting in or upon

motors or other electrical equipment in such quantities as to produce overheating through normal

radiation being prevented, or from being deposited upon incandescent lamps;

(c) Easily ignitable fibres or materials producing combustible flyings are manufactured, handled, or usedin a free open state; or

(d) Easily ignitable fibres or materials producing combustible flyings are stored in bales or containers butare not manufactured or handled in a free open state.

In both Canada and the United States, there are three classes of hazardous locations. They are as follows:

Class I- A location where there is a danger of explosion due to the presence of a flammable gas or vapour.

Class II- A location where there is a danger of explosion due to the presence of a flammable dust.

Class III- A location where there is a danger of explosion or flash fire due to the presence offlammableibres or flyings.


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Divisions/ZonesCEC/NEC Division Classification IEC Zone ClassificationClass I, Division 1:

Where ignitable concentrations can exist under

normal operating conditions; may exist frequently

because of repair, maintenance or leakage; or mayexist due to breakdown of equipment in conjunction

with an electrical failure.

Class I, Zone 0:

Where ignitable concentrations are present

continuously or for long periods of time.

Class I, Zone 1:

Where ignitable concentrations are likely to exist

under normal operations; may exist frequently

because of repair, maintenance or leakage; may

exists due to breakdown of equipment inconjunction with an electrical failure; or adjacent toClass I, Zone 0 locations.

Class I, Division 2:

Where volatile flammable liquids are stored, etc. in

closed containers; where ignitable concentrations

are normally prevented by positive pressure

ventilation; or adjacent to Class I, Division 1

locations.

Class I, Zone 2:

Where ignitable concentrations are not likely to

exist in normal operation or may exist for a short

time only; where volatile flammable liquids are

stored, etc. in closed containers; where ignitable

concentrations are normally prevented by positive

pressure ventilation; or adjacent to Class I, Zone 1

locations.


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Ignition-related Properties

Maximum Experimental safe Gap.

Minimum Igniting Current or Ratio.

Minimum Ignition Energy.

Test or estimate using the Le Chateliers

Principle.

Results found in NFPA 497.


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Gases and Vapours

Gas CEC/ ECCo e IECCo e3

cetylene Group3

Group IICHydrogen Group

4

Group II4

+ H25

thylene Group C Group II4

6

ropane Group7

Group II3

Coal8

ines Gaseous8

ines Group 1


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Temperature CodeIECTemperature Co e Temperature, C North merica Temperature

Co e

T1 450 T1

T2 300 T2

280 T29

260 T2@

230 T2C215 T2A

T3 200 T3

180 T39

165 T3@

160 T3C

T4 135 T4

120 T4A

T5 100 T5

T6 85 T6


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Common Gas Characteristics

Group Gas or Vapour LEL (%) UEL (%) SIT (C)

A Acetylene 2.5 80.0 299

B Hydrogen 4.0 75.0 550

C Diethyl ether 1.9 48.0 160

C Ethylene 3.1 32.0 435

C Hydrogen

Sulphide

4.3 45.0 260

D Ammonia 15.0 28.0 651

D Butane 1.9 8.5 372

D Gasoline 1.4 7.6 215

D Methane 5.3 15 537

D Carbon

Monoxide

12.5 74.2 605

D Propane 2.2 9.5 493


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Hazardous Dust

The classi B ication o B areas containing dusts, B ibres, and B lyings is someC hat diB B

erent B rom that B or gases

and vapours. InD

orth America the classi B ication B or Hazardous Dust, Class II, and HazardousE

ibres,

Class III, is B urther divide into tC o Divisions. Hazardous Dust has material F roups assigned, as C ell.

Classificatio

aterial CategoryG

etal Dust Class II, F roupH

Coal Dust Class II, F roupE

F rain andI

lastic Dust Class II, F roup FE

ibres andE

lyings Class III

ivisio s

Co itio s Classificatio

Dust orE

ibres andE

lyings in P uspension Division 1G

etal Dust in P uspension or P ettled on P urB aces Division 1

Q ther Dusts orE

ibres andE

lyings P ettled on

Horizontal P urB aces

Division 2


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Hazardous Dust Europe

Zone 20: An area in which combustible dust, as a cloud, is present continuously or frequently, during

normal operation, in sufficient quantity to be capable of producing an explosible concentration of

combustible dust in mixture with air.

Zone21: An area not classified as Zone 20 in which combustible dust, as a cloud, is likely to occur during

normal operation, in sufficient quantities to be capable of producing an explosible concentration of

combustible dust in mixture with air.Zone 22: An area not classified as Zone 21 in which combustible dust, as a cloud, can occur infrequently,

and persist only for short period, or in which accumulations or layers of combustible dust can give rise to

an explosive concentration of combustible dust in mixture with air.

Zones 21 and 22 are very similar to our Division 1 and 2, respectively, and Zone 20, like Zone 0 for gases

and vapours, is a new concept in North America. The new Zone 20 is intended to cover locations such asthe inside of hoppers, silos, cyclones, filters, dust transport systems, blenders, mills, dryers, and bagging

equipment; areas in which a dust cloud is almost always present.


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Common Dust Characteristics

Group Dust Cloud IT(C) ayer IT(C)

Aluminium 650 760

agnesium 620 490

ranium 20 100

Coal itts 610 180Coal D ( ) 160

Coal it ( ask) 160

Coal Dip (AB) 180

Coal Cau (AB) 200

Al al a 460 200

Co ee 410 220

Cornstarch 380 200

Wheat 480 220

Wheat lour 380 360

olyurethane 550 390


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Methods of ProtectionType of Protection Identification

Flameproof (Explosion-Proof) d

Intrinsic Safety ( 2-fault) ia

Intrinsic Safety (1-fault) ib

Pressurization p

Increased Safety e

Oil Immersed o

Powder Filled q

Encapsulated m

Zone 2 Apparatus n

Special Protection s


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Protection Methods In Use

Portables are Intrinsically safe.

Fixed Equipment is either Intrinsically Safe or

Flameproof. Fixed Equipment may also involve a third type of

protection known as Increased Safety.


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Approved Flameproof Protection Method Installation

Remote Sensor

Approved

Sealing Fitting

Division or

Zone Boundary

Conduit or Approved Hazardous Location Cable must have approved Sealing

Fittings within 18 (450 mm) of an arcing device, and at Boundaries.

Hazardous Location Cable and Sealing Fittings must be approved for the

Hazardous Location where it is to be installed.

Only use the Manufactures approved Epoxy.


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Non-incendive Protection Method and Flameproof

Enclosure Installation

Remote Sensor

Approved Sealing

Fitting

Class I, Division

2 Boundary

Non-hazardous

Location

Non-hazardous

..approved

Wiring Method

Control

Room

EquipmentStandard

Electrical Box

Non-incendive Barrier

Non-hazardous

approved Wiring

Method

Flameproof

Gas Detector

Ex n

Barriers

Non-Incendive for installation in Division 2 Locations when both the

input power and relay outputs are connected to Non-Incendive sources

not to exceed 32V dc (Power Input) and 24V dc (Relay Output.)


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Intrinsic Safety Installation

Hazardous location Non-hazardous Location

I.S. Sensor

I.S.

Transmitter

Approved

Sealing Fitting

Control Room

Equipment

I.S. Barrier

Conduit or other Enclosure


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Intrinsic Safety InstallationAssociated equipment


I.S. Sensor

I.S.

Transmitter

Approved

Sealing Fitting

Approved

Associated

Control RoomEquipment I.S.

Outputs



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Intrinsic Safety Installation withExplosion-proof Enclosure


Approved

Sealing Fitting

Control Room

Equipment


Transmitter

I.S. Barrier

I.S.

Sensor

Explosion-proof

Conduit

Explosion-proof Enclosure


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Safety Barriers

Intrinsically Safe [Ex I] method of protection

I.S. Barrier Ex ia [2 fault] Ex ib [1 fault]

Required Class I, Division 1,Zone 0, Zone 1

[I.S. Plant Rat needs 1, RigRat II

needs 8.]

Class I, Zone 1

Not Required Class I, Division 2, Zone 2 Class I, Division 2, Zone 2

1. Protection Method Ex ib is not allowed in a Class I, Division 1 or Zone 0 Area.

2. BW Technologies Intrinsically safe detectors are approved Ex ia method.

3. Barriers are usually mounted in Control Rooms outside industrial areas.

4. In cases of installation of barriers in a hazardous area, they must be mounted in an enclosure which

is suitability certified for the degree of hazard encountered.

5. European Standards do not allow I.S. Barrier installation in Zone 0.

6. Sealing Fittings are required where I.S. wiring crosses Divisions, Zones, or Non-hazardous

locations.

7. Sealing Fittings are required within 18 inches of all ports of a Flameproof Enclosure.


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I.S. BarrierTwo types of certified systems: Loop Approval and Entity Approval.

Three types of I.S. Barriers: Grounded Safety Barrier, Grounded Repeater and

Ungrounded Repeater.

The wiring method must meet the requirement for ordinary locations for the class of

circuit defined.

Limiting Energy

I.S. Barrier Field Device

Open Circuit Voltage, Voc Vmax, Maximum Voltage Allowed

Short Circuit Current, Isc Imax, Maximum Current AllowedAllowed Capacitance, Ca Ci, Internal

Capacitance

Allowed Inductance, La Li, Internal

Inductance

Ca and La include the Capacitance and Inductance of Cables.


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Class I ProtectionProtection Techniques Vs Zones and Divisions for Class I (Gases and Vapours) Equipment

CSA/UL/IEC Standard

Permissible Protection Techniques

CSA/UL National Standard

Permissible Protection Techniques

Zone 0:

Ex ia (Intrinsic Safety, 2-fault)

Zone 1:

Ex ib (Intrinsic Safety, 1-fault)

Ex d (Flameproof)

Ex e (Increased Safety)

Ex o (Oil Immersed)

Ex p (Purged and Pressurized)Ex q (Power Filled)Ex m (Encapsulated)

All Zone 1Those permitted for Division 1

Division 1:

Intrinsic Safety (Ex ia)

Explosion-Proof

Purged and Pressurized

All Division 1

Zone 2:

Ex n (non-sparking/non-ignition-capable)

Those permitted for Division 2.

Division 2:

Non-ignition-capable arcing partsNon-ignition-capable heating parts

Non-incendive

Those permitted for Zone 1 and 2, except Ex d

that contains incendive normally arcing and

sparking, or heated parts.

Notes:

1. Equipment suitable for Zone 0 is also suitablefor Zone 1 and Zone 2.

2. Equipment suitable for Zone 1 is also suitablefor Zone 2.

Note:

Equipment suitable for Division 1 is also suitable

for Division 2.


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Hazardous Zone

Installation[Flameproof /Increased

Safety Design]

Flameproof Gas

Detector or other Ex d

Device Zone 2 or

Non-

HazardousZone

Approved Nipple Fitting

Approved Sealing Fitting

Installed within 18' (450mm)

of the Ex d or Arcing Device.

Ex e Increased Safety Box

ith Ex e terminals inside

The EnclosureApprovedEx e Fitting

Approved

Ex e

Fitting

Approved

Controller or

other Device

Approved Sealing

Fitting required

where any Cable

crosses into another

Classification

Boundary.

Ex d Flameproof

Enclosure

containing Arcing

Device

Approved Nipple

Fitting

Approved Sealing

Fitting

Notes:

1. Hazardous Location Cable

and Sealing Fittings must be

approved for the Hazardous Zone

where it is installed.

2. Flameproof Sealing Fittings

are required on the Increased

Safety [Ex e] Enclosure if there are

normally arcing parts inside the

box. Otherwise approved

Compression fittings that maintain

the Ingress Protection rating of the

Ex e Enclosure must be used to

seal the Cable.

3. Ex d and Ex e protection

methods are not to be used in a

Zone 0 area.

Ex e Increased Safety

Box with no arcing parts

Approved Ex e Fitting

Cables

to other

Devices

If in Zone 2, install

Sealing Fitting at

Entries of arcing

devices.


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Protection for Class II & III

Protection Techniques Vs Divisions for Class II (Dust) Equipment

Area Protection Method

Division 1 Dust-ignitionproof

Intrinsic Safety

Pressurized

Division 2 Dusttight

Non-incendive

Non-sparkingPressurized

Any Class II, Division 1 method.

Protection Techniques Vs Divisions for Class III (Fibres and Flyings) Equipment

Area Protection Method


Intrinsic Safety


Intrinsic Safety


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Equipment Marking

EEx ia d s IIC T6 T amb. -40C Ta 50C

Class I, Gr. A, B, C, D Max. Amb: 50C.

EEx d IIB H2 T3 T amb. -40C Ta 50C

AEx d IIB H2 T3 T amb. -40C Ta 50C

Class I, Div. 1, Gr. B, C, D T3C Max. Amb. 50C

Class I, Zone 1, Gr. IIB H2 T3C Max. Amb. : 50C

II 1 G


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ATEX Directive

II1 G


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Equipment Marking

EEx ia d s IIC T6 T Amb. -40C Ta 50C

Class I, Div. 1, Gr. A, B, C, D max. Amb. 50C


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EEx d IIB H2 T3 T Amb. -40C Ta 50C

AEx d IIB H2

T3 T Amb. -40C Ta 50C

Equipment Marking


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Equipment Marking

Class I, Div. 1, Gr. B, C, D T3C Max. Amb.; 50C

Class I, Zone 1, Gr. IIB H2 T3 Max. Amb.; 50C


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The purpose of electrical apparatus designed to

minimize the risk of ignition is to allow industry to

handle situations where electrical power and signals

can be used in hazardous atmospheres. The risk posed

is never considered to be eliminated as this would be

impossible to guarantee. The risk must be lowered to

levels that are deemed acceptable by the law, and allinterested parties in Safety.

It is the consequences of an industrial explosion that

are potentially catastrophic and therefore cannot be

ignored.

Documents

Fire Expo Los Ion Principles