What is ATEX certification?
ATEX Certification is a explosion safety certification for the European Union given to equipment tested and approved to be intrinsically-safe.
There are two European Directives in place for the control of explosive atmospheres :
ATEX stands for atmosphères explosibles. It’s a European Union directive from the European Committee for Standardization that covers “equipment and protective systems intended for use in potentially explosive atmospheres.” An atmosphere can be explosive for several reasons, including flammable gases, mists or vapors, or combustible dust.
All equipment and protective systems intended for this type of use in the EU must meet ATEX health and safety requirements.
Directive 1999/92/EC (also known as ‘ATEX 153’ or the ‘ATEX Workplace Directive’)
Directive 2014/34/EU (also known as ‘ATEX 114’ or ‘the ATEX Equipment Directive’)
Example of a ATEX marking
II 2G d IIB T4
The above marking means the following
Equipment group: II
Equipment Category is 2 ( suitable for use in Zone 1)
G is for Gas
d if for Flameproof enclosure
IIB is for Gas Grouping B like Ethylene
T4 is Temperature class 4 which is a maximum surface temperature of 135 deg C
Common products for ATEX Certification
|Common products FOR WHICH ATEX Certificate is possible|
|Automatic lubrication systems- Atex certified|
|Atex certification for – Computers used in Explosive Atmosphere is possible|
|Atex certification for -Complex earthing clamps with and without cord|
|Atex certificate for Electrical motors|
|Atex certificate for Electrical pump with integrated electrical motor|
|Atex certificate for Electrical fan with integrated electrical motor|
|Atex certification for Heating cables|
|Atex certified for Mechanical brakes|
|Atex certification for Mechanical gears|
|Atex certification for Phones and similar equipment e.g. walkie-talkies, head phones etc.|
|Atex certificate for Plugs and socket outlets|
|Atex certificate for Rotary valve|
|Atex certificate for Switches for fixed electrical installations|
|Atex certificate for Torch|
|Atex certificate for Extension cord with plug|
|Atex certificate for Cable reel|
|Atex certification for Flame arresters|
|Atex certificate for Vent panels (for explosion pressure relief)|
|Atex certification for Cable Glands|
|Atex certification for Empty enclosures|
|Atex Certification for Spark arrester|
ATEX CERTIFICATION PROCEDURE MAP
Understanding ATEX markings
The Simple map below will help you in understanding various aspects of ATEX marking and also differentiate betwwen ATEX and IEC Ex markings
Eurocert – A Approved Notified body for ATEX
What are ATEX Zones?
How to decide Which ATEX Certification marking you require?
This can be quite challenging if you are new to ATEX certification. Below is a guide for selection of Protection marking for various zone
|SELECTION GUIDE FOR ATEX APPARATUS|
|0 (Category1 equipment Requires a EPL of a)||ia||Intrinsic safety|
|0(Category1 equipment Requires a EPL of a)||s||Special protection|
|1(Category2 equipment Requires a EPL of b)||d||Flame proof|
|1(Category2 equipment Requires a EPL of b)||ib||Intrinsic safety|
|1(Category2 equipment Requires a EPL of b)||p/p1||Pressurization /Purging for zone 1|
|1(Category2 equipment Requires a EPL of b)||m||Encapsulation|
|1(Category2 equipment Requires a EPL of b)||e||Increased safety|
|1(Category2 equipment Requires a EPL of b)||v||Ventilation for Zone 1|
|1(Category2 equipment Requires a EPL of b)||s||Special protection for Zone 1|
|2(Category3 equipment Requires a EPL of b)||n|
|2(Category3 equipment Requires a EPL of b)||p||Pressurization for Zone 2|
|2(Category3 equipment Requires a EPL of b)||p1||Purging for Zone 2|
|2(Category3 equipment Requires a EPL of b)||v||Ventilation for Zone 2|
|2(Category3 equipment Requires a EPL of b)||s||Special protection for Zone 2|
What are the Various Gas Groups?
Three Gas Groups are defined
IIA- For Propane
IIB- For Ethylene
IIC- For Hydrogen /Acetylene
Lower Explosive Limit (LEL)
It is the minimum concentration of vapor or flammable gas in the atmosphere below which the gas atmosphere is not explosive.
Upper Explosive Limit (UEL)
It is the maximum concentration of vapor or flammable gas in the atmosphere above which the gas atmosphere is not explosive.
Examples of Explosive Limits
|Substnace||LEL (%)||EUL (%)|
So the above defines the atmosphere ranges which could be explosive and require protection strategies .
MIEC / MIE
Another important concept is MIEC-most easily ignited concentration (MEIC), the amount of energy required to cause ignition is minimal.
The critical energy at the MEIC is called minimum ignition energy (MIE).
What are the Various Temperature Classes? and What is the effect of Temperature in ATEX classification / Certification
All materials have a spontaneous ignition temperature (SIT), also know as auto ignition temperature (AIT). This is the temperature at which the material will ignite on its own.
If the temperature of a Gaseous and vapor mixture is raised, the amount of electrical energy required for ignition will reduce, and will be “zero” at the AIT.
– Equipment is identified with a temperature class
• Either identified by a ‘T’ rating or by a temperature in degrees C.
-The temperature class identifies the hottest temperature that the equipment can obtain.
|T CLASS||Maximum Surface Temperature|
|T1||450 deg C|
|T2||300 deg C|
|T3||200 deg C|
|T4||135 deg C|
|T5||100 deg C|
|T6||85 deg C|
What is principle of Intrinsic Safety in ATEX?
This Safety principle is different light from other protection methods. It differs from the various “enclosure” methods where the intent is to minimize the chances of electrical ignition or minimize its effects.
Intrinsically Safe’ equipment means that the equipment is designed for use in hazardous environments / explosive atmospheres. Due to the high levels of combustible substances in these areas, it is essential that such a device guarantees that no spark is cause or reaches a high temperature
any equipment which is not marked intrinsically safe may cause a spark and must not be brought onto Zone 0 or 1
A example of this is use of Zenner Diode Barrier which is an ultra high speed switch and monitoring device. This barrier checks the current drawn by the device in the hazardous area, if the current exceeds a limit defined by the manufacturer – even about40-50 mA – the circuit is “cut” and the outgoing cables are switched to earth. All this happens within micro-seconds
What if my product is a machinery or has internal pressure and I need ATEX certification?
If your product is a machinery then you require Ce Certificate for machinery
prior to starting of the ATEX project. Similarly if it has a internal pressure of more than 0.5 bar it may require a PED certification