Explosion Protection

MARKING / LABELLING

1

Why do we have to label Ex

Equipment?

ARP 0108 : 2014

Paragraph 7

• Due to the potential disastrous

consequences if the wrong equipment

is used, it is of vital importance that all

equipment be clearly labelled with

information supporting the safe use of the

equipment.

24 April 2012 - PRINCE GEORGE — Two dozen workers were on shift in the

sawmill section of Prince George's Lakeland Mills Monday night when a loud

'boom' shook the building and fire erupted around them. The workers fought

their way through the smoke and flames, desperate to get out of the building

before the power failed and there was another explosion.

Veranus Gas Plant Explosion in Australia May 2009

An explosion at a grain elevator in Kansas has claimed six lives on October 29th

2011. Three victims were found initially but unstable concrete and other damage

forced crews to temporarily call off their search at the Bartlett Grain Co. facility

in Atchison, about 50 miles NW of Kansas City.

On February 7, 2008, a huge explosion and fire occurred at the Imperial Sugar

refinery northwest of Savannah, Georgia, causing 14 deaths and injuring 38

others, including 14 with serious and life-threatening burns. The explosion was

fuelled by massive accumulations of combustible sugar dust throughout the

packaging building

Text from: ARP 0108 : 2014

Paragraph 7

Such marking must be durable, visible in all

configurations and legible.

7.3 Test for durability

7.31 Rub the marking lightly for 15 seconds with a piece of

cloth soaked with water

7.3.2 After drying, rub for a further 15 seconds with a piece

of cloth soaked in white spirit.

Note: White spirit is also known as mineral spirits, mineral

turpentine, turpentine substitute, petroleum spirits and

solvent naphtha content of 25%, by mass, of c7 to c12

aromatic hydrocarbons.

Repair Labels

ARP 0108: 2014 Annex A

A.13 Any repairer shall attach to the product a durable,

legible and noticeable label that gives at least the

following information:

a) The repairer’s certificate number (when operating

under an approved certification mark scheme for Ex

certified equipment)

b) The IA certificate number

c) The name of the repairer

d) The month and year of repair or overhaul.

Repair Labels - continue

ARP 0108: 2014 Annex A

A13 Note: It is not intended that the need for a repair label

be applicable to routine maintenance or

replacement of identical parts.

A.14 The label fitted by the original equipment

manufacturer (OEM) shall not be removed, but

labels fitted by previous repairers shall be removed. If

the OEM label is missing, the repairer may submit the

finished product to an ATL and have the product re-

certified to the current national standard. In this case,

the repairer shall fit a supplier’s plate displaying the

new IA certificate number.

What about the IA Certificate

Text from an IA Certificate:

Example of Ex marking on a Junction Box

E Ex de II B T4 G b Ta = 53°C

What does this all mean?

S-XPL/03796 (X) (U)

Max Dissipated Power = 3.65 W

E – Indicates that the product is built and tested according to European Standards.

E Ex de II B T4 G b Ta = 53°C

Ex – Indicates that the product is Explosion Protected.

E Ex de II B T4 G b Ta = 53°C

All of the main methods or Protection

Concepts, used to achieve overall Ex

protection are indicated, using one or

more of the following abbreviations:

E Ex de II B T4 G b Ta = 53°C

• d – Flameproof (druckfest)

• e – Increased Safety (erhöhte sicherheit)

• m – Encapsulation (moulding)

• p – Pressurization (or purging)

• q – Sand filled (quenching)

• i – Intrinsic Safety

• n – Non sparking (Zone 2 only)

• ta – Combustible Dusts

• tb – Conductive Dusts

• tc – Ignitable Fibres

And many others

E Ex de II B T4 G b Ta = 53°C

I - for Apparatus Group I - For mines

susceptible to firedamp. Re Methane

present

II - for Apparatus Group II -

Flammable locations in all other

industries. (Surface)

III - for Apparatus Group III –

Explosive dust atmospheres other

than mines susceptible to fire damp.

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Group I

Firedamp found in Mines, re.

Methane, Coal Dust and other gasses

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Group IIA

Acetone, Acetic acid, Toluene, etc.

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Group IIB

Town gas, Ethylene, etc.

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Group IIC

Hydrogen, Acetylene, Carbon

Disulphide.

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Group III

Explosive dust atmospheres other than

mines susceptible to fire damp.

E Ex de II B T4 G b Ta = 53°C

Gas Group I, IIA, IIB or IIC

Apparatus suitable for IIC is

automatically suitable for IIA & B

but not visa versa.

E Ex de II B T4 G b Ta = 53°C

Temperature Class:

The maximum surface temperature that apparatus is permitted to reach, even under fault conditions. Ambient temperature must also be considered

E Ex de II B T4 G b Ta = 53°C

• T1 – maximum surface temperature 450°C

• T2 – maximum surface temperature 300°C

• T3 – maximum surface temperature 200°C

• T4 – maximum surface temperature 135°C

• T5 – maximum surface temperature 100°C

• T6 – maximum surface temperature 85°C

Apparatus suitable for T5, for example, can

be used with T1 to T4 but NOT visa versa.

E Ex de II B T4 G b Ta = 53°C

Temp

Class

T1 T2 T3 T4 T5 T6

Ignition

Temp

>450ºC >300ºC >200ºC >135ºC >100ºC >85ºC

Wheat Flour

Methane Aluminium Dust Coal Dust

Iron Powder

Acetone Ethanol Petrol Acetaldehyde

Ethane I-Amyl Acetate Diesel Ethyl Ether

Ethyl Acetate N-Butane Kerosene

Ammonia N-Butyl Alcohol Paraffin

Acetic Acid N-Hexene

Carbon

Monoxide

Methanol

Propane

Toluene

Coal Gas Ethylene

Hydrogen Acetylene Carbon

Disulfide

Ethyl Nitrate

Hazardous Substance:

G if the flammable substance is a Gas,

including vapors or mists.

D if the flammable substance is a Dust.

E Ex de II B T4 G b Ta = 53°C

M if the flammable substance is in a Mine.

EPL - Equipment Protection Level:

a for apparatus suitable for Zone 0, 1 and 2 (if preceded by G,M)

a for apparatus suitable for Zone 20, 21 and 22 (if preceded by D,M)

b for apparatus suitable for Zone 1 and 2 (if preceded by G,M)

b for apparatus suitable for Zone 21 and 22 (if preceded by D,M)

c for apparatus suitable for Zone 2 ONLY (if preceded by G,M)

c for apparatus suitable for Zone 2 ONLY (if preceded by D,M)

E Ex de II B T4 G b Ta = 53°C

Gases and Vapours

There are three zones for gases and vapours:

Zone 0

an area where an explosive mixture of flammable gas, vapour or

suspended liquid droplets/mist with air is continuously present, or

present for long periods.

Zone 1

an area where an explosive mixture of flammable gas, vapour or

suspended liquid droplets/mist with air is likely to occur during

normal operation.

Zone 2

an area where an explosive mixture of flammable gas, vapour or

suspended liquid droplets/mist in air is likely to occur under

abnormal operating condition of the facilities.

Zone 0 is the most severe zone (the highest probability of flammable

atmosphere presence). Equipment for this zone needs to be very well

protected against providing a source of ignition. Ex i - equipment

Dusts

There are three zones for dusts:

Zone 20

A place in which an explosive atmosphere in the form of a cloud of

combustible dust in air is present continuously, or for long periods,

or frequently.

Zone 21The atmosphere is likely to contain ignitable concentrations of inflammable dust or fibres under normal working conditions.

Zone 22

An area in which dust clouds might occur infrequently and persist for only short periods or combustible dusts might be present under abnormal conditions.

The presence of dust layers does not automatically lead to the dust zone. The

likelihood of the dust layer being disturbed to create a cloud needs to be

considered. Dust layers also need careful consideration in terms of ignition

temperature. Because the dust layer can make the equipment under it hotter

than normal, a factor of safety is applied to the layer ignition temperature.

Ta =Ambient Temperature:

• The ambient (surrounding air)

temperature needs to be kept below

53°C to maintain a T4 Surface

temperature rating

E Ex de II B T4 G b Ta = 53°C

Max Dissipated Power = 3.65 W

S-XPL/03796 (X) (U)

E Ex de II B T4 G b Ta = 53°C

There is always a lot of

confusion with

“Max Dissipated Power”

S-XPL/03796 (X) (U)

Max Dissipated Power = 3.65 W

A common question people ask is: “can they use this

junction box to terminate cables for a 4kW pump

motor?” The answer is yes because the power is consumed

outside the junction box.

Dissipated power means power consumed within the

junction box and it is limited to 3.65 watts to prevent you

from heating up the box from the inside, which will ultimately

affect the T4 rating of the junction box.

E Ex de II B T4 G b Ta = 53°C

S-XPL/03796 (X) (U)

Max Dissipated Power = 3.65 W

IA Certificate Number

This junction box was tested by the

EXPLOLABS Test Laboratory.

(X) – means there is a special condition that

needs to be complied with.

(U) – The junction box is a component or is in-

complete, it might only be complete if it is

fitted with Ex de cable glands.

E Ex de II B T4 G b Ta = 53°C

Lets look at USA marking of Ex Equipment

Class I, Division 2 & Zone 2, AEx d C T5

What does this all mean?

Permitted Class:

Class I

Flammable Gases, Vapors or

Liquids

Class II

Combustible Dusts

Class III

Ignitable Fibers and Flying's

Class I, Division 2 & Zone 2, AEx d C T5

Class I, Division 2 & Zone 2, AEx d C T5

Permitted Zone:Division 1 and Zone 0

Where ignitable concentrations of flammable

gases, vapors or liquids can exist all of the

time or some of the time under normal

operating conditions

Zone 1

Where ignitable concentrations of flammable

gases, vapors or liquids can exist some of

the time under normal operation conditions.

Division 2 and Zone 2

Where ignitable concentrations of flammable

gases, vapors or liquids are not likely to

exist under normal operation conditions.

Class I, Division 2 & Zone 2, AEx d C T5

American National Standard

Class I, Division 2 & Zone 2, AEx d C T5

Explosion Protected

Class I, Division 2 & Zone 2, AEx d C T5

• d – Flameproof (druckfest)

• e – Increased Safety (erhöhte sicherheit)

• m – Encapsulation (molding)

• p – Pressurization (or purging)

• q – Sand filled (quenching)

• i – Intrinsic Safety

• n – Non sparking (Zone 2 only)

And many others

Class I, Division 2 & Zone 2, AEx d C T5

Gas Group

A – Acetylene

B – Hydrogen

C – Ethylene

D – Propane

E – Metals

F – Coal

G - Grain

Class I, Division 2 & Zone 2, AEx d C T5

Temperature Class

• T1 – maximum surface temperature 450°C

• T2 – maximum surface temperature 300°C

• T2A - maximum surface temperature 280°C

• T2B - maximum surface temperature 260°C

• T2C - maximum surface temperature 230°C

• T2D - maximum surface temperature 215°C

• T2A - maximum surface temperature 280°C

• T3 – maximum surface temperature 200°C

• T3A – maximum surface temperature 180°C

• T3B – maximum surface temperature 165°C

• T3C – maximum surface temperature 160°C

• T4 – maximum surface temperature 135°C

• T4A – maximum surface temperature 120°C

• T5 – maximum surface temperature 100°C

• T6 – maximum surface temperature 85°C

International acronyms found on nameplates

ATEX - Atmospheres Explosive

CA - Canada

CEC - Canadian Electrical Code (CSA C22.1)

CE - Conformité Européenne, meaning "European Conformity".

CENELEC - European Committee for Electrotechnical Standardization

EU - European Union

IEC - International Electrotechnical Commission

I.S. - Intrinsic Safety

MSHA - Mine Safety and Health Administration (America and Europe)

NFPA - National Fire Protection Association (America)

NEC - National Electrical Code (America)

US - United States of America

UL - Underwriters Laboratory (American worldwide safety consulting

and certification company)

FM - FM Global is a Johnston, Rhode Island-based mutual insurance

company in America

Any Questions?

Eldon Kruger

Marketing Director

Tel No: 011 955-2190

E-Mail: eldonk@pratley.co.za

www.pratley.com