Regulations
ATEX valves: what they are and when you need them
Published 25 March 2026 · 9 min read
In plants where flammable gases, vapours or dusts are present, equipment must be designed not to ignite explosions. The European ATEX directive sets the requirements. Here's what it means for industrial valves.
What ATEX means
ATEX comes from the French "ATmosphères EXplosibles" (explosive atmospheres). Two complementary EU directives:
- Directive 2014/34/EU (ATEX 114) — Requirements for manufacturers of equipment for potentially explosive atmospheres
- Directive 1999/92/EC (ATEX 153) — Requirements for employers operating in explosive atmospheres (zone classification, worker protection)
When we talk about "ATEX valves", we mean they comply with 2014/34/EU and are certified for use in classified zones.
Zone classification
Gas and vapour zones
| Zone | Definition |
|---|---|
| Zone 0 | Explosive atmosphere present continuously or for long periods |
| Zone 1 | Explosive atmosphere likely in normal operation |
| Zone 2 | Explosive atmosphere unlikely, only for short periods |
Dust zones
| Zone | Definition |
|---|---|
| Zone 20 | Combustible dust cloud present continuously |
| Zone 21 | Dust cloud likely in normal operation |
| Zone 22 | Dust cloud unlikely, only occasionally |
Equipment categories
Group II — All industries (except mines)
- Category 1 — For Zones 0/20 — "Very high" protection level
- Category 2 — For Zones 1/21 — "High" protection level
- Category 3 — For Zones 2/22 — "Normal" protection level
A valve certified Category 2G (G = gas) can be used in Zone 1 and Zone 2. Category 3G only in Zone 2.
Temperature classes
The temperature class indicates the maximum surface temperature the equipment can reach — it must not exceed the auto-ignition temperature of the gas present:
| Class | Max °C surface | Example gases covered |
|---|---|---|
| T1 | 450 | Methane, ammonia, CO |
| T2 | 300 | Butane, propane, ethanol |
| T3 | 200 | Petrol, hexane, kerosene |
| T4 | 135 | Acetaldehyde, diethyl ether |
| T6 | 85 | Carbon disulphide |
Are valves ATEX equipment?
It depends on the type:
- Manual valves (ball, butterfly, gate) — Generally NOT covered by ATEX directive if no electrical parts. Cannot be ignition source. Many manufacturers certify them anyway for commercial reasons.
- Electric actuated valves — The actuator must be ATEX certified. The valve+actuator assembly requires certification.
- Pneumatic actuator + solenoid — The solenoid coil must be Ex rated. Pneumatic actuator itself is not ignition source.
- Solenoid valves — Must be ATEX certified if installed in classified zones.
When you need ATEX valves
Oil & Gas
Refineries, fuel depots, offshore platforms, pipelines. Extensive Zone 1 and 2.
Chemical plants
Solvent production/storage, flammable gas processes.
Biogas and biomethane
Anaerobic digesters, upgrading, storage. Methane = Zone 1/2 around joints and valves.
Food and pharmaceutical
Areas with combustible dusts (flour, sugar, processing powders). Zone 21/22.
Conclusion
ATEX compliance is not optional — it's a legal requirement for installing equipment in classified zones. Correct selection of valves and actuators is essential for plant and worker safety.
Roffia distributes ATEX certified valves and actuators from brands like Spirax Sarco, Danfoss and Valpres. Contact us for selection support.