Zone 0 / Zone 20
Explosive atmosphere continuously present — e.g. inside filled tank. Most stringent class; Category 1 equipment mandatory. AODD metal body models can be certified for Zone 0.
Technical Guide
ATEX Pump
Guide
Explosive atmospheres directive, Zone classification, Ex protection types and ATEX certified pump selection guide — complete reference in 5 comprehensive sections.
What is ATEX?
Obligation of Safe Equipment in Explosive Atmosphere
ATEX (ATmosphères EXplosibles), European Union directive regulating equipment and protection systems used in environments containing explosive gas, vapor, mist or dust. This legislation with directive number 2014/34/EU mandates the use of ATEX approved equipment in the chemical, petrochemical, pharmaceutical, food, mining and paint sectors. Turkey has enacted a regulation (2016/R-0033) in compliance with this directive; facilities exporting to the EU or adopting EU standards are directly subject to the ATEX directive.
Air-operated double diaphragm (AODD) pumps eliminate the fundamental electrical ignition risk structurally since they do not use an electric motor. This inherent safety advantage makes AODD pumps the preferred type in all ATEX zones including Zone 0. However, to prevent static electricity accumulation, antistatic/conductive material selection and documented grounding connection are mandatory; without these requirements ATEX certification is considered invalid.
ATEX certification is a legal requirement in the EU as of 1 July 2003. For equipment manufactured before this date, the obligation to review and replace with new equipment if necessary belongs to the end user. Zone classification responsibility also belongs to the end user; the pump manufacturer supplies the certified model appropriate to the zone information provided by the user.
- Zone 0/1/2 (gas) and Zone 20/21/22 (dust) classification
- AODD pump: no electricity = no electrical ignition risk
- Antistatic conductive body and documented grounding mandatory
- Notified Body approved Ex certificate + CE mark = directive compliance
- Gas group IIA / IIB / IIC and T class matching is critical
- Zone determination responsibility belongs to the end user (operator)
Zone Classes
ATEX Zone Classification
Zone 1 / Zone 21
Explosive atmosphere forms occasionally during normal operation. Category 2 equipment required; most common application area for AODD. Chemical filling lines, process reactor surroundings typical examples.
Zone 2 / Zone 22
Explosive atmosphere rare and brief under abnormal conditions. Category 2 or 3 equipment can be used. Storage area surroundings, locations with rare leakage risk typical applications.
Ex Certification
Ex certificate issued by Notified Body and EU Declaration of Conformity prove directive compliance. Notified Body approval is mandatory for Category 1 and 2 equipment.
Gas Group IIA / IIB / IIC
The explosion group of the flammable substance in the environment directly affects pump selection. IIA (propane, acetone) low risk; IIB (ethylene, H₂S) medium; IIC (hydrogen, acetylene) highest risk group.
Temperature Class T1–T6
Pump surface temperature must absolutely not exceed the ignition temperature of the gas. T4 (135°C) is the most common class in industrial applications; T6 (85°C) for substances with low ignition points such as carbon disulfide.
Zone Reference
ATEX Zone Classification
Complete Reference Table
| Zone | Description | Hazard Frequency | Category | Typical Application |
|---|---|---|---|---|
| Zone 0 | Explosive gas atmosphere continuously present | Continuous / Long-term | Category 1G | Inside tank, reactor internal volume |
| Zone 1 | Explosive atmosphere occasionally present during normal operation | Intermittently | Category 2G | Chemical filling line, process reactor surroundings |
| Zone 2 | Explosive atmosphere rarely present under abnormal conditions | Rare / Short-term | Category 3G | Storage area surroundings |
| Zone 20 | Combustible dust cloud continuously present | Continuous | Category 1D | Inside dust silo, dust production area |
| Zone 21 | Combustible dust cloud occasionally present during normal operation | Intermittently | Category 2D | Screening, grinding, packaging points |
| Zone 22 | Combustible dust cloud rarely and briefly formed | Rarely | Category 3D | Powder storage area perimeter |
ATEX Questions
ATEX Pump Selection
Questions
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No. Only Category 2 (or higher protection) ATEX certified equipment can be used in Zone 1 areas. Use of non-compliant equipment constitutes a directive violation and requires severe legal sanctions; it also carries critical risk from a work safety perspective.
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No. Not using an electric motor alone does not ensure ATEX compliance. Conductive/antistatic material that prevents static electricity accumulation, documented grounding connection, and official Notified Body approved ATEX certification are mandatory. Standard plastic PP housing is not conductive and is not suitable for ATEX.
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Pumpport PA Series metal diaphragm pumps are offered as ATEX certified. You can share your zone and category requirements with our technical team to determine the appropriate model.
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Zone classification is entirely the responsibility of the end user (operator). The pump manufacturer only supplies the appropriate certified model based on the zone information specified by the user. If zone determination is done incorrectly, directive compliance cannot be achieved.
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ATEX is a legal requirement in the European Union (under 2014/34/EU directive scope). IECEx is a voluntary certification system at global level. Both meet similar technical requirements but their geographic validity areas differ. For facilities in Europe, ATEX certification is mandatory and sufficient.
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Significant modifications initiate a re-certification process. Routine maintenance with original parts and wear part replacements generally do not affect certification; however, compliance with manufacturer documentation and approved parts lists is required.
ATEX Pump Guide
Sections of the guide
Sections
What is an ATEX Pump?
Zone classification, Ex certification and basics of pump use in explosive atmospheres.
ReviewATEX Directive 2014/34/EU
Equipment groups, categories, Ex protection types and Notified Body certification process.
ReviewATEX Pump Types
Comparison of centrifugal, AODD, screw and peristaltic ATEX pump types.
ReviewATEX Pump Selection Criteria
Zone, explosion group, fluid analysis and material conductivity: 7-step selection guide.
ReviewATEX vs Normal Pump
Differences in design, engine technology, certification and total cost of ownership.
Review