Why, when and where do you need ATEX products

ATEX (Ex) products are required in environments where there is a risk of explosive atmospheres being present. ATEX stands for "Atmosphères Explosibles," the French term for explosive atmospheres. Industries such as oil and gas, petrochemical, pharmaceuticals, mining, chemical processing, agriculture, waste treatment and food processing often contain ATEX zoned areas.

The need for ATEX certified products arises due to safety concerns. Explosive atmospheres occur when concentrations of flammable gases, vapours, mists, or combustible dusts mix with air in a ratio that can ignite, if an ignition source is applied. Typical ignition sources include discharge of static electricity, naked flames and sparks created during hot works. To prevent accidents and protect workers and equipment in such environments, ATEX products may be required.

Storage, mixing and transfer of paints, solvents and fuels are typical applications where ATEX equipment is necessary, due to concentrations of flammable gases or vapours. Machining or sanding of metals and storage of foodstuffs and agricultural fertiliser can lead to creation of explosive air/dust concentrations.

The use of ATEX products is mandated by the ATEX directives, which are European Union (EU) directives outlining the essential safety requirements for equipment and protective systems intended for use in explosive atmospheres. The European Economic Area (EEA) applies these directives and globally they are a widely adopted safety standard. Certain regions, such as the United States, have their own standards.

The ATEX directives are complex and as such, please seek specialist advice before pumping, mixing, filtering and filling flammable liquids. Give extra consideration to liquids exhibiting low conductivity (due to slow electrostatic charge dissipation) and/or low flash points.

What is the ATEX Directive 2014/34/EU?

The ATEX Directive 2014/34/EU provides guidance and recommended design features that must be included to reduce explosion risk and contain an explosion in the event of equipment failure. The standard ensures that manufacturers apply the correct design criteria and testing to prove their equipment qualifies for Ex approval. Equipment that is compliant with the ATEX Directive has a CE mark and red Ex marking. Additional markings create a code, which describes the suitability of the equipment for use in different environments and atmospheres, taking into consideration factors such as surface temperature, above or below ground use and zoned area category. You can find an example ATEX designation code for a barrel pump here.

The aim of the Directive is to ensure equipment used in explosive atmospheres is manufactured and designed to reduce or eliminate risk of explosion and to contain any flash fire within the equipment. Therefore a fire or explosion cannot spread further. Equipment manufacturers employ “zone separation” methodology to their designs for this purpose. Electrical components and machinery with moving mechanical parts that could create heat or sparks eg. if a malfunction occurs, must comply with the Directive. Such equipment includes pumps, electric motors, compressed air motors and valve actuators.

Items of equipment without moving parts eg. hoses, pipework, fittings, do not have to be certified under the ATEX directive, as they are not deemed to be at risk of malfunction (or they do not create enough energy) to cause heat or sparks. Some such items may also be classed as “intrinsically safe” and as such, they do not require certification under ATEX. However, items such as hoses and fittings must be certified as being conductive. Otherwise there is a risk of electrostatic charge build-up which could result in a spark if static electricity is suddenly discharged, eg. by connecting a non-conductive hose to a piece of equipment, eg. a pump.

See further information regarding drum pump equipotential bonding here

What are typical ATEX products?

ATEX products encompass a wide range of equipment, including but not limited to:

Electrical equipment: eg. switches, sensors, lighting fixtures, motors, control panels, and other electrical devices.

Mechanical equipment: eg. pumps, compressors, fans, mixers and other rotating machinery.

Protective systems: eg. explosion-proof enclosures, flame arresters, explosion venting panels and suppression systems.

When are ATEX products essential?

You require ATEX certified products once qualified assessors complete a Zoned Area Classification exercise and the extent of each zone has been determined. In the UK, this exercise may involve a DSEAR risk assessment. Once Zoned areas are determined, choose equipment with the appropriate ATEX designation and certification. However, also consider specific environmental factors when selecting equipment.

Here are some scenarios where ATEX products are typically essential:

Petrochemical Industry: Oil refineries, petrochemical plants, offshore platforms and other facilities involved in the extraction, processing, and storage of flammable fuels and highly flammable solvents.

Chemical Industry: Chemical and fertiliser manufacturing plants, laboratories and facilities where workers handle flammable chemicals or reactive substances.

Mining Industry: Mines may contain potentially explosive gases or dust, making ATEX approval vital for mining equipment, underground lighting, ventilation and mineral processing facilities.

Pharmaceutical Industry: Processes within the pharmaceutical industry may involve flammable or explosive substances eg. preparation and mixing of alcohol gels.

Food and Beverage Industry: Facilities that produce combustible dust/air mixtures, such as grain silos or flour mills. Distilleries where flammable vapours are present.

Waste Treatment and Recycling: Waste treatment tanks, composting sites, biological treatment facilities and recycling centres may produce flammable gases or dust.

What is DSEAR?

DSEAR stands for The Dangerous Substances and Explosive Atmospheres Regulations 2002. This regulation requires employers in the UK to control risks to safety from fire, explosion and substances that are corrosive to metals. DSEAR risk assessments therefore go hand in hand with Zoned Area Classification and ATEX equipment considerations.

Definition of Zoned Area Classification

The specific requirements for ATEX products partly depend on the zone classification, which categorises areas according to the likelihood and duration of the presence of explosive atmospheres. The classifications are Zone 0, Zone 1, Zone 2 for gases and vapours, and Zone 20, Zone 21, Zone 22 for dusts. The lower the Zone classification, the higher the chance of an explosive atmosphere being present.

See further information regarding classification of Zoned areas here

See drawing of typical Zone area classification for a barrel pump application here.

What are ATEX certified pumps?

An ATEX pump is certified to operate in potentially explosive atmospheres. ATEX pumps are specifically designed to ensure they do not ignite flammable gas, vapour, or dust / air mixtures that may be present in hazardous environments. Consideration is given to potential malfunction of a pump or drive motor, which may cause excessive heat to be generated. Industries such as petrochemicals, pharmaceuticals, chemicals and mining commonly use ATEX pumps. This is due to a high risk of explosive atmospheres being present during dispensing, mixing and transfer of flammable fuels or solvents.

To meet ATEX standards, pumps undergo rigorous testing and must comply with strict safety requirements. The pumps are constructed from electrically conductive materials that reduce the risk of electrostatic charge build-up and spark or heat generation. Electrical components, such as motors and switches, use flame-proof enclosures that can contain a flash fire. Additionally they have intrinsically safe components wherever possible. Additionally, ATEX pumps have safety features including earth connection points, explosion-proof enclosures, thermal overload protection and sealed cable glands.

Note that you may require an ATEX approved pump even when pumping non-flammable liquid, if you have installed the pump in a Zoned area.

When should you use ATEX pumps?

Follow some simple guidelines:

• The pump is used in a Zoned area (as determined by Zoned Area Classification or DSEAR risk assessment)

• Pumping flammable liquids with flash point below 50 deg C.

• Pumping low-conductivity flammable liquids (due to slow dissipation of electrostatic charge), particularly liquids with low flash point.

When pumping flammable liquids, please consider:

• High flow rates, filtration, separation and mixing increase electrostatic charge in liquids, which increases the possibility of a spark being created.

• Avoid splash-filling vessels if possible, due to creation of excess vapour.

• Small bore pipes, bends and valves can increase electrostatic charge.

• Earth bonding requirements

• Hoses and fittings must be conductive and certified, if appropriate. This is to ensure that electrostatic charge can be dissipated effectively and to eliminate any electrical potential differences between components in the pumping system.

What options are available for an ATEX explosion proof pump?

At Flux Pumps, we produce a range of Ex drum and barrel pumps and air-operated double diaphragm pumps. You can use these pumps in Zoned areas, identified by the red Ex symbol.

Flux ATEX drum pumps (UK) are manufactured primarily from 316 stainless steel, which is an ATEX approved material. The pumps also have conductive PTFE bearings and impellors that comply with ATEX pump requirements.

Flux ATEX centrifugal pumps include our FP424, F430 and F425 series models. These are designed for low viscosity fluids up to a maximum viscosity approx. 1000 mPas. The F430S FOOD is approved for food and beverage applications, carrying Ex, FDA CFR 21 and EC 1935 / 2004 certification. This pump is perfect for transferring ethanol and finished alcoholic beverages in distillery applications.

VISCOPOWER Ex-approved progressive cavity drum pumps are available for use in high viscosity applications.

Flux F460 and FBM4000 electric motors and F416 compressed air powered motors have Ex certification. There is a common misconception that compressed air motors are safer than electric motors when used in a Zoned area. However this is not the case. Each product carries a specific ATEX type-code and they are equally safe to use.

Flux ATEX impeller pumps cost from approximately £1,500, increasing to over £4,000 for progressive cavity pumps. Prices vary depending on many factors. Such as pump size and type, motor power, and materials of construction. Additionally whether options such as discharge hose, swaged hose connections, earth cables and flowmeters are specified.

Flux produces RFM series air-operated ATEX diaphragm pumps, constructed from conductive PTFE and polypropylene materials. These pumps are available with a choice of elastomers for handling specific fluids.