Many industrial processes employ agents such as combustive, combustibles and flammables considered potentially explosive when getting in contact with air.
Companies and plants are responsible for ensuring that regulations are applied to equipment as well as to workers' conditions. The European Union introduced the ATEX 2014/32/UE certification in 2014 (regrouping 94/9/EC and 99/92/EC together for bringing into harmony the state members' laws on equipment and systems used in potentially explosive atmospheres.).
As a producer of chemical pumps, Argal must respect the security requirements to guarantee safe operations in these atmospheres: our products are compliant with 2014/32/UE regulation and thus marked ATEX.
ATEX, explained
The ATEX regulation is divided into groups and categories. The conformity evaluation depends on this division which consents to establish the procedure to follow regarding the material of construction for the pumps. There are 2 groups: GROUP I is for the use in underground mines whether GROUP II is for the use in all other places. Argal products are concerned about GROUP II, which is subdivided into 3 categories according to the protection level needed:
cat. 1 - Equipment that is intended for use in areas where an explosive atmosphere is present continuously, frequently, or for an extended period. cat. 2 - Equipment that is intended for use where an explosive atmosphere is likely to occur in normal operation and must ensure a high level of protection. cat. 3 - Equipment that is intended for use where an explosive atmosphere is unlikely to occur in normal operation and must ensure a normal level of protection.
The hazardous areas are categorized into 2 different zones according to the risk of explosion.
ATEX in the form of gas Zone 1 - Explosive Atmosphere in the form of gas (likely to occur - a mixture of flammable agents and air in the form of gas, vapor, or dust) Zone 2 - Explosive Atmosphere in the form of gas (unlikely to occur - in case of formation, it is for a short period).
ATEX in the form of dust Zona 21 - Area where it is occasionally likely to occur. Zona 22 - Area where it is unlikely to occur.
ARGAL Ex-proof pumps are to be used in surface plants (GROUP II) with the related categories and zones allocated according to the conformity evaluation.
The concerned equipment is labeled ATEX Zone 2 or Zone 1, with a specific marking with essential indications to determine operable areas:
Zone 2 (II 3G Ex h IIB T4 Gb X) | Zone 2 (II 3D Ex h IIB T135°C Db X)
Zone 1 (II 2G Ex h IIB T4 Gb X) | Zone 1 (II 2D Ex h IIB T135°c Db X)
The marking also contains potentially explosible gas references to evaluate its hazardousness. ATEX regulation classifies gases per group:
Group I – methane Groupe IIA – propane Group IIB – ethylene Group IIC – hydrogen/acetylene
Another important reference concerns the temperature of these agents. Each piece of equipment in a dangerous area is classified according to the maximum temperature that the surface can reach. The material used must always be inferior to the spontaneous combustion temperature of the explosive agents. Temperatures are divided into six classes:
Most ARGAL pumps can be constructed according to ATEX standards: it depends on the type of pump and the material used.
Our ATEX AODD pumps, both plastic, and metal are suitable to operate in explosive atmospheres which, according to the ATEX standards, is classified as Zone 2 (II 3G Ex h IIB T4 Gb X | II 3D Ex h IIB T135°C Db X). For applications of ATEX pumps in Zone 1 (II 2G Ex h IIB T4 Gb X | II 2D Ex h IIB T135°C DB X), we manufacture pumps with bodies and other “conductive” parts for all plastic and metal versions. ATEX versions are made upon request.
For the ATEX centrifugal pumps, we offer different constructive solutions. Some are made of thermoplastics reinforced with a conductive material, the carbon fiber, such as ROUTE series, auxiliary pumps made of E-TFE + carbon fiber. Others are made of pure Polypropylene with an external armor or in E-CTFE with carbon fiber conductive liner coating – these two solutions can be applied to the FRONTIERA series. Naturally, centrifugal pumps must be equipped with an ATEX motor if the atmosphere requires it.
But which are the plants and systems equipped with pumps considered as potentially explosive areas?
Examples of sectors and applications requiring ATEX marking pumps
ATEX standards are applied in the industries where immediate chemical-physical reactions occur (from liquid or solid-state to gaseous one with energy-releasing):
- Condensed phase in the separation process found in the chemical industry, petrochemical, metallurgic industries as well as in power plant.
- B.L.E.V.E (Boiling Liquid Expanding Vapor Explosion) – it occurs when some breaches are present in tanks or basins that contain a pressurized liquid (such as petrol, liquefied gas). It can also happen inside cooling or steam systems.
- U.C.V.E (Unconfined Vapor Cloud Explosion) – it occurs when a combustible or fuel is burning so rapidly that it creates an explosion, such as in agriculture where liquefied hydrocarbons are used (propane, ethylene)
- Explosive combustion in enclosures such as gas turbines installed in power plants, chemical plants, mines, food industry (sugar plant, mill plant…) as well as in pharmaceutical or textile manufacturing.
- Gas runaway in nuclear reactors (azote, refrigerant, combustible such as uranium, plutonium, anhydride carbon)
These situations can be verified in various industrial processes, from transformation to storage of dangerous chemical agents transferred from one tank to another.
The chemical industry is exposed to explosion risks during the production process where vapors, solvents, hydrogen are generated by chemical reactions as well as during the transformation phase of chemical agents. An explosion can also occur if some equipment has a runaway because the main liquids used in chemical processes are dangerous.
In the petrochemical industry, petroleum refineries and gas treatment plants are examples of highly hazardous areas where explosion risk is constant: the liquids used are all inflammable (hydrocarbons), and they can generate explosive atmospheres even at ambient temperature. In the metallurgic and power sector, the risk of explosion is high as well because of the use of a highly flammable organic agent: carbon coke.
Explosions also occur in industries that produceflammable materials such as leather, paper, wood industries where wood, wood flour, cork, cellulose, and leather dust are potentially explosive. Regarding the sector of plastics, risks are high too. Transporting and storing plastics and rubbery (PVDF) is risky as the powder can be formed in many processes.
Hazardous zones can also be found in the laboratories: oxygen tanks and flammable gas warehouse, glove box (where toxic and flammable materials are produced), hi-tech production line, test room, or even the sterilization room (use of ethanol).
Some other industry is considered highly hazardous area: Aeronautics, aerospace, railway, and marine construction require the use of micro-dusts, paintings, propellants, solvents that can turn into explosive because of high temperatures or contact with air. Automotive and landfill plants must be compliant with ATEX standards as they produce and eliminate dangerous toxic waste such as biogas.
In the food industry processes, the production, transport, and storage of cereals can be dangerous as once turned into dust; they have explosive properties. The use of alcohol for sterilizing controlled areas also increases the explosion risks.
The importance of ATEX standards: safety for the workers, for the plant, and the environment.
Industrial damages due to explosions, combustions, or runaways can create massive disasters for the environment and also for the workers. The ATEX directive internationally regulates the safety level of equipment to avoid hazardous situations. ARGAL products are compliant with the ATEX directive so that pumps are entirely safe to be used in dangerous atmospheres. The risk is evaluated and studied in a very accurate approach as we aim at eliminating or reducing it to its minimum already during the conception phase. ARGAL pumps ensure reliability and safety to operators using them.
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Concerning our range of pneumatic and centrifugal ATEX pumps made of fiberglass, we offer a special version made of a mixture of resin-coated with carbon fiber conductive liner.
