Pump World

ATEX | PUMPS & STANDARDS

31/01/2018

ARTICLE #1 



 

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.

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ATEX - EXPLANATION

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 categorised 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, vapour 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 ATEX 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 labelled ATEX with a specific marking with essential indications to determine operable areas:
 

Zone 2 (II 3/3 GD IIB T4)

 
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 equipment in a dangerous area is classified according to the maximum temperature that surface can reach. The material used must always be inferior to the spontaneous combustion’s temperature of the explosive agents. Temperatures are divided into six classes:

T1 –  max 450°C (Gas: hydrogen, methane | Dust: fuligin, PVC, aluminium, sugar)
T2 – max. 300°C (Gas: ethylene, acetylene | Dust: polyethene, carbon dust)
T3 – max. 200°C (Gas: kerosene)
T4 – max. 135°C (Gas: ether ethylene)
T5 – mac. 100°C
T6 – max. 85°C (Gas: disulfuric carbon)


ARGAL PUMPS MARKED WITH ATEX LABEL

Most of 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” (Series II 3/3GD C IIB T4). For applications of ATEX pumps in “Zone 1” (Series II 2/2gd IIB T4), we manufacture pumps with bodies and other “conductive” parts for all plastic and metal versions.

ATEX PUMP | ASTRA 75-100 


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-CTFE + carbon fiber. Others are realised in pure Polypropylene with an external armour or in E-CTFE with carbon fiber conductive liner coating – these two solutions can be applied to FRONTIERA series. Naturally, centrifugal pumps must be equipped with an ATEX motor if the atmosphere requires it.

ATEX PUMP | ZGE with armour coated with conductive liner of carbon fiber.

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.

ATEX PUMP | SATURN EVO ZGS coated with conductive liner of carbon fiber.

But which are the plants and systems equipped with pumps considered as potentially explosive areas?


ATEX APPLICATION SECTORS: SOME EXAMPLE

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 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 pressurised 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 turbine 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 a tank to another.

The chemical industry is exposed to explosion risks during the production process where vapours, 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 produce flammable 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 powder can be formed in the 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 sterilisation room (use of ethanol).
Some other industry is considered as 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 sterilising controlled areas also increases the explosion risks.

 


THE IMPORTANCE OF ATEX STANDARDS: A SAFETY FOR THE PLANTS BUT ESPECIALLY FOR THE WORKERS.

Industrial damages due to explosions, combustions or runaways can create massive disasters for the environment but also for the workers. The ATEX directive internationally regulates the safety level of equipment to avoid hazardous situations.
Argal products are compliant with 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.