Hazardous Area Certification

Airacom ATEX Reference Guide explains European hazardous location protection methods and markings.

Hazardous area reference guide

Understanding ATEX

PROTECTION METHODS

Protection Method
IEC
Intrinsic Safety
ia
60079-11
Intrinsic Safety
ib
60079-11
Flameproof
d
60079-1
Pressurization
p
60079-2
Increased Safety
e
60079-7
Increased Safety
e
60079-7
Encapsulation
m
60079-18
Oil Immersion
o
60079-6
Powder Filling
q
60079-5
Non-sparking
n
60079-15
General Requirement
60079-0
Inspection & Maintenance
60079-17

PROTECTION
CONCEPTS

Protection Concepts
Symbol
How it Works
Category
Increased Safety
Ex e
No arcs, sparks or hot surfaces
2 & 3
Non-sparking
Ex nA
No arcs, sparks or hot surfaces
3
Flameproof / Enclosed Break*
Ex d Ex nW
Contain the explosion and quench flame (*Enclosed Break can also be noted as Ex nC)
2 & 3, 3
Quartz/Sand Filled
Ex q
Contain the explosion and quench flame
2 & 3
Intrinsic Safety / Energy Limitation
Ex ia / Ex ib / Ex nL
Limit energy of sparks; limit the temperature
1, 2 & 3 / 2 & 3 / 3
Pressurised / Simplified Pressurisation
Ex p / Ex nP
Keep the flammable gas away from any hot surfaces and ignition capable equipment
2 & 3 / 3
Encapsulation
Ex m
Keep the flammable gas away from any hot surfaces and ignition capable equipment
2 & 3
Oil Immersion / Restricted Breathing
Ex o / Ex nR
Keep the flammable gas away from any hot surfaces and ignition capable equipment
2 & 3 / 3
Special
Ex s
Any proven method
1, 2 & 3

FIRE
TRIANGLE

Push to Talk Cloud
Push to Talk Cloud

Flammable & Combustible Substance

Push to Talk High Voice Quality
Push to Talk High Voice Quality

Air / Oxygen

Push to Talk Group Communication
Push to Talk Group Communication

Ignition Source

All three elements of the fire triangle must be present for ignition to occur.

TEMPERATURE
CLASSES

Max. Surface Temperature
Fahrenheit
T-Class
450° C
(842° F)
T1
300° C
(572° F)
T2
200° C
(392° F)
T3
135° C
(275° F)
T4
100° C
(212° F)
T5
85° C
(185° F)
T6*
Equipment Group:
Equipment Category:
Atmosphere:
I (Mines)
M1
Methane & Dust
I (Mines)
M2
Methane & Dust
II (Above Ground)
1
Gas, Vapor, Mist, Dust
II (Above Ground)
2
Gas, Vapor, Mist, Dust
II (Above Ground)
3
Gas, Vapor, Mist, Dust
Protection Level:
Required Protection Performance & Operation:
Very High
Two faults, remain energised and functioning
High
Severe normal operation, De-energize in exp. atm
Very High
Two faults
High
One fault
Low
Normal operation

GAS
GROUPS

Typical Material
Methane
I
Propane
IIA
Ethylene
IIB
Hydrogen
IIC
Acetylene
IIC
All Gases
II