ATEX FANS

ATEX Fans with Ex Increased Safety Motors & Sparkproof Materials

 

Casals, a leading Global ATEX fan manufacturer, manufacture our ATEX Fans according to ATEX directive standards. The EU notified body, LOM, holds a technical file for each spark resistant fan when required. For safety and transparency, each unit is clearly ATEX labelled to ensure traceability back to source. ATEX fans are safe to use in hazardous areas with gas zones 1 and 2, and dust zones 21 and 22. 

Manufacturers design spark resistant fans with materials that prevent sparks and friction. This helps to avoid ignition in dangerous environments. These include stainless steel, polypropylene and aluminum.

An explosion-proof fan lowers the risk in explosive areas, reducing the chance of ignition in hazardous environments. We ensure our Casals ATEX fans meet UK safety standards and regulations under ATEX 2014/34/EU for use in the UK hazardous market. Our technical fan product team are available to select the right ATEX fan to suit your assessed requirements, start a chat or send an enquiry for ATEX industrial fan assistance.

 

Important Information Regarding The ATEX Directive & ATEX Fan Selection

ATEX is always changing, which can be confusing for customers who aren't familiar with hazardous areas. UK & EU ATEX Directives and legislation regulate the design of ATEX fans in the UK market. You must correctly select and place fans to suit the hazardous area classification they're planned to be used in. We can help you to choose the right ATEX fan for your gas or dust application.

 

The below seeks to assist our customers with understanding some of the key principles that affect ATEX fan selections. Please send us your enquiry for review. Additionally, please read the information below. This will help you to understand the intricacies of ATEX fan selection and placement in a highly regulated market.

 

Our team has received extensive education, experience, and training in ATEX concepts. All our explosion proof fans are manufactured and certified for use in hazardous areas for placement into the UK market. We advise our customers to be weary of false ATEX certifications or suppliers who don't ask stringent questions during ATEX fan selection and supply.

 

Overview of ATEX and The 2014/34/EU Product Directive

ATEX is an acronym derived from the French expression ATmosphères EXplosibles. It exists for our purposes in the form of two European directives. 

  • a 'product directive' labelled 2014/34/EU previously 94/9/EC (ATEX 100) covering manufacturing standards of components, and as
  • a 'workplace directive' labelled ATEX 99/92/EC (ATEX 137) which seeks to ensure that people are protected against the risk of blast injuries or asphyxiation by dangerous substances. 


ATEX Directive 2014/34/EU came into force in 2016, and assists with establishing a uniformity to the approach taken when supplying and distributing equipment for explosive atmospheres. This covers both the electrical and non-electrical/mechanical components design, and the certification of hazardous equipment. 

Everyone involved in the specification, manufacture, installation, and use of equipment in flameproof zones bears some degree of responsibility towards ensuring that the law concerning flameproof equipment is upheld. Therefore the ATEX Directive ensures that when placing products on the market, or using them for their own purpses, manufacturers and authorised representatives ensure that they have been designed, manufactured and certified in accordance with the essential health and safety requirements set out in supporting legislation. (see BS EN14986:2017 standards for design criteria of fans below.)  



BS EN 14986:20217 Standards: Mechanical Design Criteria of Fans for Explosive Atmospheres

Even though Britain has left the European Union, there are still European laws, legislative pieces and standards that have been adopted as a British standard or as formal guidelines. One example is the European standard EN 14986:2017 which has the status of a British standard through BS EN 14986:2017. EN 14986:2017 is known as the “Design of fans working in potentially explosive atmospheres” legislation and specifies the constructional requirements for ATEX fans constructed in Group IIG (Suitable for non-mining gas environments) of explosion groups IIA, IIB and hydrogen, categories 1 (zone 0), 2 (zone 1) & 3 (zone 2), and Group IID (Suitable for non-mining dust environments) categories 2 (zone 21) and 3 (zone 22) for use in explosive atmospheres.

What does BS EN 14986:2017 cover?

The standard sets out the requirements for the design, construction, testing and marking of complete fan units intended for use in potentially explosive atmospheres in air containing gas, vapour, mist and/or dusts. These atmospheres may exist inside, outside, or both inside and outside of the fan.   The standard is applicable to fans working in ambient atmospheres and with normal atmospheric conditions at the inlet, having:

  • absolute pressures ranging from 0.8 bar to 1.1 bar,
  •  and temperatures ranging from −20 °C to +60 °C,
  • and maximum volume fraction of 21 % oxygen content,
  • and an aerodynamic energy increase of less than 25 kJ/kg.   

So you don’t have to read the entire standard, we’re covering a small section in this article to assist you in ensuring the ATEX fan you purchase is designed, built, and specified in line with the legal guidelines.  

BS EN 14986: 2017 Standards: Mechanical Design Criteria of Fans for Explosive Atmospheres

Section 4.4.1 of the standard describes how industrial fans should be designed to make them suitable for placement on the EU or UK market, in explosive atmospheres.  


“Fans for operation in potentially explosive atmospheres shall be of rigid design.”  


There’s lots of aspects that cover rigid design, and to test this, fan manufacturers should complete impact tests. “Impact testing should be undertaken on casings, supporting structures, guards, protective devices, and other external parts. Then if the deformation resulting from these tests at the most vulnerable point is so small that the moving parts of the fan do not come into contact with the casing, then the component is classed as having a rigid design.”

Therefore, any fan design that’s placed on the market will have been impact tested using approved testing procedures and these results will have been sufficient to pass the tests. 

Clearance between Rotating Elements and the Fan Casing

The most important safety feature of any industrial fan construction, to minimise ignition, is the clearance between the rotating elements and the fan casing. This is clearly stated in BS EN 14986 at clause 4.4.2. “The minimum clearances between rotating parts such as the impeller and fixed parts, such as the fan casing, shall be at least 0.5% of the relevant contact diameters (diameter of the rotating part at the point where it can contact a stationary part) of the finished component, but shall not be less than 2mm in the axial or radial directions nor need be more than 13mm.”

The fan manufacturer should design and construct the fan ensuring that the clearances are well maintained under all conditions covered by the intended use.  Clearances may change with rotation, temperature and due to vibrations or belt drive tension. Clearances should be adhered to in application considering potential casing distortion, ductwork and pressure drops that may affect.  

Fan Casing

To satisfy the mechanical design requirements specified in the standard, the fan casing should be of a substantially rigid design with leakage protection, adequate shaft seals and fully welded joints. The fan should be capable of withstanding the lowest inlet pressure that can be generated by the fan itself when the inlet is closed, without causing contact between the casing and moving parts. Leakage declaration is compulsory when the internal and external zones of the fan are different.  

Impellers

Impellers shall be of a rigid design and shall be able to withstand a test run at a minimum of 115 times the maximum operational rotating speed for at least 60 seconds without causing an ignition risk, i.e. the impeller shall not contact the casing. An impeller design that enables a primary stress calculation based on 2/3 of the yield stress shall be deemed to satisfy the requirements for a rigid design without testing. The security coefficient at the rotating element in our tests is a minimum of 20%. This information is recorded in the technical record. 


We ensure that all of our ATEX fans are constructed in line with the mechanical design criteria of fans for explosive atmospheres legislation. Each fan will be clearly labeled with it's non-electrcal Ex h (explosion proof) marking and correct zone use.  


Directive Compliant ATEX Fan Constructions Using Permissible Material Pairings
Why are Permissible Material Pairings so Important?
As a part of the legisation noted in the accordion above, the design of the non-electrical components of a fan are one of the most important aspects of explsoion protection and prevention.

In the normal operation, or in the event of malfunctions (whether standard or rare), possible friction caused by areas of contact can occur. As stated in the ATEX directive, and adopted into UK legislation, potential areas of contact between the rotating elements and fixed components of equipment for use in potentially explosive environments, should be manufactured from materials in which the risk of ignition caused by friction and friction impact sparks, hot spots or hot surfaces is minimised. This applies specifically to the construction and manufacture of explosion proof industrial fans. Ignition risks cannot be completely eliminated but can be significantly reduced by taking suitable constructive measures for avoiding ignition sources. European and UK Directives are clear on the permissible material pairings that are suitable to reduce the ignition source caused by friction of these two areas: rotating and fixed.
Material pairings are considered carefully by fan manufacturers and authorised bodies, who use their theoretical and practical knowledge, coupled with the known application conditions for the environment in question. The safest material pairing and other compulsory technical specifications that determine how a product is chosen for an explosive environment by taking a full holistic view of the ATEX environment. Material pairings are devised and communicated in legislation documentation to minimise the risk of an explosion. Industrial fans in systems or machinery, are generally not supervised continuously and contact between rotating and stationary, fixed components may occur in a particular area for an unknown amount of time, potentially in long intervals.


DSEAR Regulations and Hazardous Area Assessments for Hazardous Environments

Whether your work activities create, control or release flammable gases or vapours, such as vehicle paint spraying, exhausting toxic fumes from production activities, or you handle fine organic dusts such as grain flour or wood, a DSEAR audit will ensure you meet the relevant legislation for your industry and reduce the risk of serious injury or explosions. In short if you think there is a risk of explosion with any of the substances or activities being undertaken, a hazardous areas classification can ensure you stay on the right side of safe, protecting systems, processes, buildings, and employees from harm.

There are lots of companies in the UK that can be contracted to complete a risk assessment and compile a hazardous area document tat can be used to source equipment for potentially explosive environments. Important Information In line with the ATEX Directive it is strictly the responsibility of the end user to undertake a DSEAR risk assessment to ensure that ATEX classifications are properly defined in terms recognised by ATEX 2014/34/EU. Please contact SGS on 0151 350 660 or visit www.sgs.co.uk to book an assessment.

Please note that under DSEAR regulations, customers are required to explicitly state their hazardous area classification information before a selection can be made. If you're not sure who to contact to obtain this, we can supply organisations that can help you to remain compliant and safe.  


Understanding ATEX Gas and Dust Zones
The ATEX gas or dust zone is required in all occasions of fan selection. The ATEX zone determines the frequency an presence of the hazardous gas or dust in the application, so that the equipment protection level can be selected correctly. 


When is the gas or dust present in the area the fan will occupy? 
  • rarely (zone 2 or 22) - level c required
  • ocassionally (zone 1 or 21) - level b required
  • always (zone 0 or 20) - level a required
Zones 0, 1 and 2 relate to gases and vapours, while zones 0, 21 and 22 relate to combustible dusts. 
Equipment Protection Levels:
  • highest level protection - level a
  • moderate level protection - level b
  • standard level protection - level c

ATEX zones for gases/vapour:

Zone 0 (gases/vapours) or Category 1G: an area in which an explosive mixture is continuously present or present for long periods.

Zone 1 (gases/vapours) or Category 2G: an area in which an explosive mixture is likely to occur in normal operation.

Zone 2 (gases/vapours) or Category 3G: an area in which an explosive mixture is not likely to occur in normal operation and if it occurs it will exist only for a short time.

ATEX zones for dust:

Zone 20 (dusts) or Category 1D: an area in which an explosive mixture is continuously present or present for long periods.

Zone 21 (dusts) or Category 2D: an area in which an explosive mixture is likely to occur in normal operation.

Zone 22 (dusts) or Category 3D: an area in which an explosive mixture is not likely to occur in normal operation and if it occurs it will exist only for a short time.

Temperature Classes (T-Classes) and Auto Ignition Temperatures
Temperature classes, also known as T-classes, are designed to prevent the auto-ignition of gases and dusts.
Auto-ignition is the lowest temperature that a gas or dust will spontaneously ignite in air, without a spark or flame, due to its own heat in its environment, causing an explosion. Every gas on earth, as taught in chemistry has an ignition temperature. 

T-classes help to choose ATEX components for use with specific gases and dusts. 
Hazardous area apparatus is classified according to the maximum surface temperature produced under the maximum operating capacity at an ambient temperature of 45°C, or as otherwise specified. For example a motor. The standard classifications are:

T1     450°C
T2     300°C
T3     200°C
T4     135°C
T5     100°C
T6     85°C
As highlighted, this is the lowest temperature at which a gas, vapour or dust will b ignited without a spark or flame. 
Example:
Hazardous Gas: Hydrogen
Ignition Temp: 584.85°C
T Class: Greater than 450°C therefore T1
The maximum surface temperature on components used within the hazardous are containing Hydrogen should not exceed 450°C to prevent the auto ignition of Hydrogen gas. All equipment that generated a surface temperature greater than 450 cannot be used in a Hydrogen atmosphere. 
ATEX Motor Definitions used In ATEX Fans
While all ATEX fans should be certified Ex h to show that they are mechanically constructed in line with ATEX Directive guidelines, so should the electrical parts. This includes the ATEX ratings of the motors, whether standard or external rotor motor. 

For gas environments, the protection principle ensures that an ignition does not occur from sparks and arcs from the motor. 
Ex eb - increased safety, explosion protected - suitable for zone 1
Ex ec - increase safety but the lowest and normal level of ATEX protection, also known as reduced risk protection and for motors is non sparking - suitable for zone 2
Ee Db - flameproof - suitable for zone 1

Ex tb - offers a high level of protection in category 2 / zone 21 dust applications

Ec tc - offers a normal level of protection in category 3 / zone 22 dust applications

Authorised Representatives

A manufacturer may appoint an authorised representative to safely distribute, integrate and sell ATEX components into their respective markets. An authorised representative shall perform the tasks specified in the mandate received from the manufacturer. 

Axair act as the authorised representative for SEAT Ventilation, enabling us to act as the leading party for the sale and distribution of zone 2 ATEX carbon loaded polypropylene fans into the UK hazardous area market. All technical testing is dutifully carried out under self certification by SEAT Ventilation, with technical files and ATEX certificates for all polypropylene fans held with them, the manufacturer and lodged with notified bodies where required.

Notified Body Certification or Self Certification in ATEX Fan Compliance

There are a two main routes to ATEX certification that determine if a component is designed and constructed in line with the ATEX Directive. Namely self certification and via 3rd party notified bodies. The degree of risk determines the route that is compulsory to take to certification. 

What is a Notified Body? 

A notified body is an organisation designated by a member state to assess the conformity of certain products before being placed on the market.

The involvement of a notified body is greater when the components are intended to work in an area requiring a high level of safety e.g zone 0 certified equipment. 

What is Self-Certification/Self Declaration and What Can Be Self Certified?

As there are no legal requirements for additional 3rd party certification in lower risk equipment/lower risk zones such as:

  • category 2 (zone 1 & 21) for mechanical, and
  • category 3 (zone 2 & 22) for both mechanical and electrical equipment 

Internal quality and control over production is maintained by the manufacturer who signs the declaration and makes themselves legally responsible for the equipment compliance. In the distinction between the two, the non-electrical/mechanical is considered less critical and therefore does not need a notified body that verifies the design and production directly in the company but deposits the technical file to the notified body. Manufacturers of fans are included in this framework. 

Therefore the below must be assessed by a notified body to make the component compliant

  • Category 1 (zone 0 & 20) for both mechanical and electrical
  • A technical file should be lodged for category 2 (zone 1) mechanical following self assessment
  • A technical file should be lodged for category 3 (zone 2) electrical following self assessment

Key Notes: The ATEX Directive 2014/34/EU applies to all mechanical and electrical equipment to be used in potentially explosive atmospheres. Both electrical and mechanical equipment may ignite explosive atmospheres and therefore appropriate measures of protection are taken to prevent this ignition. Self certification and notified body certifications provide evidence that the ATEX product is suitable for placement in the market, and is designed in accordance with the ATEX Directive design directions. 

Casals ATEX fans are both self certified, with technical files lodged where required, and assessed by notified body LOM in accordance with legal requirements. 

Casals Notified Body - LOM (Laboratorio Oficial J.M. Madariaga - Body No: 0163)

LOM is the chosen Notified Body Nº 0163 by Casals Ventilation to carry out third-party conformity assessment under the ATEX Directive

The acting as a third party has been one of the fundamental activities of LOM since it was created. 

In the field of explosive atmospheres, LOM acts as a certification body in regulatory schemes and in voluntary schemes, being:

  • Notified Body for the Directive 2014/34/EU od the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres.
  • Certification body of IECEx global certification scheme.
  • Additionally, LOM has developed its own certification schemes in the field of explosive atmospheres such as:
  • Certification reparatEX for workshops that carry out the repair of ATEX certified equipment.
  • Qualification of people who perform different jobs with ATEX equipment or in an ATEX environment.

LOM is a Notified Body for Directive 2014/34/EU of the European Parliament and of the Council of 26 February 2014, on the harmonisation of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres, having been authorised to carry out the following third-party conformity assessment tasks:

  • Module B: EU-Type Examination. 
  • Module D: Conformity to type based on quality assurance of the productions process. 
  • Module F: Conformity to type based on product verification.
  • Module C1: Conformity to type based on internal production control plus supervised product testing. 
  • Module E: Conformity to type based on product quality assurance.
  • Module G: Conformity based on unit verification.
The commercialisation and control in Europe of a civil explosive is regulated by Directive 2014/28/EU of the European Parliament and the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market and supervision of explosives for civil uses. 
The responsible for placing the product on the market, manufacturer, authorised representative or importer must follow one of the conformity assessment procedures defined in Article 20 of that Directive, in order to draw up the EU declaration of conformity and mark CE in this product. LOM is Notified Body Nº 0163 to carry out third-party conformity assessment tasks under Directive:
  • Module B: EU-type examination.
  • Module C2: Conformity to type based on internal production control plus supervised product checks at random intervals.
  • Module D: Conformity to type based on quality assurance of the production process.
  • Module E: Conformity to type based on product quality assurance.
  • Module F: Conformity to type based on product verification.
  • Module G: Conformity based on unit verification.

Anyone requesting information on the certification of Casals Ventilation ATEX fans certified for use in UK hazardous environments should put it in writing to [email protected].