The ATEX Directive 94/nine/EC is a directive adopted by the European Union (EU) to facilitate free trade in the EU by aligning the technical and legal needs in the member states for merchandise meant for use in most likely explosive atmospheres. CENELEC design specifications are nevertheless used. All products put on the market place or put into support in the EU for use in potentially explosive atmospheres ought to comply with the ATEX directive.
Merchandise Covered by the ATEX Directive
This directive addresses “Equipment” and “Protective Systems” which could be utilised in probably explosive atmospheres developed by the presence of flammable gases vapors, mists or dust. “Equipment” is any merchandise which contains or constitutes a prospective ignition supply and which involves specific actions to be integrated in its design and/or its set up in order to prevent the ignition resource from initiating an explosion in the bordering atmospheres. Also provided in the expression “equipment” are security or command devices put in exterior of the hazardous location but acquiring an explosion defense function. A broad collection of goods arrives inside the definition of machines, which include electrical motors, compressors, diesel engines, lights fittings, handle and communication products and monitoring and detection products. “Protective Systems” are products which protect against an explosion that has been initiated from spreading or causing harm. They integrated flame arrestors, quenching techniques, pressure relief panels and fast- acting shut- off valves.
The directive excludes the pursuing varieties of merchandise:
• Medical devices
• Products for use in the presence of explosives
• Products for domestic use
• Personal protective products
• Sea-going vessels and cellular off-shore units
• Means of transport, besides vehicles for use in most likely explosive atmospheres
• Military devices
New Item Classification Gear Groups and Categories
The ATEX Directive, in Annex I, defines two Devices Groups which are subdivided into five Products Categories.
In order to ascertain the suitable Conformity Assessment Process, the manufacturer ought to initial occur to a selection based mostly on the intended use, as to which Machines Group and Devices Category the products belongs.
Machines Groups and Classes:
Gear Group I
• Equipment Category M1
• Equipment Group M2
Devices Group II
• Equipment Group 1
• Equipment Class two
• Equipment Category 3
What Are Equipment Groups?
The two Machines Groups defined in Annex I are based mostly mining and non- mining programs.
• Equipment Group I – comprises of gear meant for use in the underground elements of mines, and to all those components of surface area set up of this sort of mines, likely to become endangered by fire damp and/or combustible dust.
• Equipment Group II – comprises of devices meant for use in other destinations likely to turn out to be endangered by explosive atmospheres.
What Are Equipment Groups?
The Equipment Classes Defined in Annex I are dependent on the level of precautions required in accordance to the likelihood of the presence of an explosive ambiance. Considering that larger amounts of precaution are a lot more costly to attain, classification of equipment into categories enables precautions to be used that are acceptable to the chance.
The 5 Equipment Categories are:
• Category M1 & M2 for mining applications.
• Category one, two, & three for non- mining apps.
Devices Class M1:
Group M1 comprises of equipment which is:
Intended for use in mines endangered by fire damp and/or coal dust Essential to stay functional, even in the celebration of rare incidents relating to equipment, with an explosive environment present, and is characterized by the implies of safety these kinds of that:
• Either, in the function of failure of one particular implies of safety, at minimum an independent 2nd indicates supplies the requisite level of protection.
• Or the requisite stage of protection is assured in the celebration of faults taking place independently of every other.
Products Category M2:
Class M2 comprises of devices which is:
• Intended for use in mines endangered by fire damp and/or coal dust. Required to be de- energized in the event of an explosive environment.
• The means of protection relating to gear in this category assure the requisite stage of defense through usual operation and also in the care of a lot more extreme running circumstances, in certain individuals arising from tough managing and changing environmental problems.
For Conformity Evaluation, Class M2 is sub- divided into:
• Electrical equipment and inner combustion engines
• Non- electrical products
Gear Group one:
Category 1 comprises of machines which is:
• Intended for use in areas which an explosive ambiance is constantly present or for lengthy intervals of time.
• Equipment in this group should assure the requisite degree of defense, even in the occasion of scarce incidents relating to products, and is characterized by suggests of protection this sort of that:
• Either, in the occasion of failure of one indicates of safety, at least an independent second suggests provides the requisite level of protection.
• Or the requisite degree of defense is assured in the function of two faults happening independently of each and every other.
Equipment Category two:
Group 2 comprises of equipment which is:
• Intended for use in areas which an explosive atmosphere is very likely to occur.
• The implies of defense relating to equipment in this class assure the requisite stage of protection, even in the event of frequent taking place disturbances or gear faults which commonly have to be used into account.
For Conformity Assessment, Group 2 is sub- divided into:
• Electrical equipment and inner combustion engines.
• Non- electrical gear.
Devices Category 3:
Group three comprises of gear which is:
• Intended for use in places which an explosive environment is unlikely to arise or only to happen infrequently or for small period of time.
• Equipment in this category ensures the requisite level of defense throughout regular operation.
The New Conformity Mark
Below the Aged Directive, the “Epsilon X” symbol indicated conformity with CENELEC needs. This symbol was permitted to be utilized to solutions which were considered to be ultimate assemblies, NOT empty enclosures or element areas this kind of as terminal blocks, operators, breather drains, and many others.
Beneath the New Directive, the “Epsilon X” symbol will transfer into the marking string and be utilized to indicate explosion defense. The “CE” mark will now indicate conformity to the ATEX Directive. This mark can only be utilized to last assemblies and not to empty enclosures or component components.
What Should I Do to Comply With the ATEX Directive 94/9/EC?
• For products that meet the scope of the ATEX Directive, you have to ensure that they comply with the Vital Specifications specified in Annex II of the ATEX Directive.
• To assure that your goods comply with the ATEX Directive, you require to adhere to the applicable Conformity Evaluation Process(s). (These processes may possibly entail the participation of a notified physique.)
What Are the Vital Needs?
The Important Needs detailed in Annex II relate to functions of gear and protective systems that are important in purchase to protect against explosions or to control the effects of incipient explosions.
The Necessary Specifications fall into three groups:
2. Needs for Devices
3. Specifications for Protective Devices
1. General Needs
- Principle of integrated explosion security
- Distinctive checking and maintenance circumstances
- Surrounding place conditions
2. Selection of Materials
- Products that could trigger explosions
- Adverse reactions involving resources
- Resistance to company ailments
- Protected operation all through foreseeable lifestyle
- Prevention of leaks
- Dust deposits
- Additional indicates of protection
- Protected opening
- Safety from other hazards
- Overloading of devices
- Flameproof enclosure systems
3. Potential Ignition Resources
- Hazards from distinct ignition resources
- Static electrical power
- Stray electric and leakage currents
- Stress compensation operations
4. Hazards Arising From External Effects
- Risk- free operation beneath specified operating ailments
- Resistance to mechanical and thermal stresses and aggressive substances
5. Requirements in Respect of Security Gadgets
- Security perform independent of measurement or handle operate
- Detection of failure – fail risk- free
- Immediate actuation of command unit
- Gear and/or protective programs made safe
- Restart lockouts
- Command and display models
- Products with measuring function for explosion defense
- Risks arising from application
6. Integration of Safety Requirements Relating to the Technique
- Manual override
- Dispersion of accumulated energy
- Energy failure
- Connections and interface
- Warning gadgets
Requirements for Machines
Within just about every Products Category the needs cover:
• Prevention of ignition resources from turning out to be energetic
• Control surface area temperatures
• Safe opening
• Prevention of dust ingress and egress
The Needs for Protective Devices cover:
- Dimensioning to decrease results of explosion to a protected level
- Positioning to protect against explosions from spreading
- Electric power failure
- Resistance to outside interference
2. Preparation and Design
- Characteristics of resources
- Shockwave resistance
- Pressure- stand up to of equipment
- Account take of pressure in peripheral devices and pipework
- Strain relief methods
- Explosion suppression devices
- Explosion decoupling techniques
- Integration into security methods
What Are the Conformity Evaluation Processes?
The ATEX Directive specifies a variety of Conformity Assessment Processes and the conditions when they must be utilized. The methods are:
• EC kind examination
• Quality assurance
• Verification modules
• Internal handle of creation
EC Type Examination
EC Kind Examination is a procedure carried out by a notified entire body to validate that a merchandise kind is in conformity with the pertinent essential requirements. The method is specified in Annex III of the directive. The notified system will look at the technical file supplied by the manufacturer and conduct this sort of inspections and tests as could be expected to show that the item variety complies with the conditions stated by the manufacturer. The notified body may advise on relevant specifications but it is in the long run for the producer to choose the intended use of the merchandise. The EC Kind Examination process culminates in a certificate issued by the notified human body, attesting that the kind as defined in the technical file complies with the directive.
Top quality Assurance Modules
There are two Quality Assurance Modules specified in the ATEX directive:
• Production Quality Assurance – which applies to Products Groups 1 and M1 and to protective techniques, and which is specified in Annex IV of the directive.
• Product Good quality Assurance – which applies to electrical gear and inner combustion engines only, in Gear Groups 2 and M2, and which is specified in Annex VII of the directive.
Each of these modules require the manufacturer to have a defined and documented process for controlling the conformity of goods to the demands of the directive as defined in the technical file accompanying the EC kind Examination Certificate(s) for the products form(s). The method have to be assessed by a notified body and be subject to periodic audit by the entire body. In addition the system could spend unannounced visits to the producer and may possibly have out inspection and/or testing of goods to verify conformity with the licensed type.
There are a few Verification Modules specified in the ATEX Directive.
• Product Verification – specified in Annex V of the directive, which applies to Devices Categories 1 and M1 and to the protective methods.
• Conformity to Sort – specified in Annex VI of the directive, which applies to electrical equipment and inner combustion engines in Equipment Groups 2 and M2.
• Unit Verification – specified in Annex IX of the directive which may well be applied at the choice of the manufacturer as an option to any other conformity evaluation modules.
Even though they vary in their certain needs, the Verification Modules all need every single item created to be inspected and examined for conformity with the demands of the directive. The Item Verification and Unit Verification processes are carried out by the notified physique, while the Conformity to Variety is carried out by the manufacturer underneath the responsibility of a notified physique. In all scenarios the manufacturer is required to draw up a Declaration of Conformity in the format defined in Annex X of the directive.
Internal Management of Manufacturing
• Internal Manage of Production applies to devices in Class two and M2 which is not electrical gear nor inner combustion engines and to products Group 3. It is specified in Annex VIII of the directive.
• Internal Control of Manufacturing is a course of action whereby the producer, on his own responsibility, carries out the necessary operate to ascertain that product which he areas on the sector comply with the requirements of the directive.