Understanding ATEX Certification for Valves in Hazardous Areas

ATEX (ATmosphères EXplosibles) certification governs electrical and mechanical equipment used in potentially explosive atmospheres across the European Union and India.

What Are ATEX Zones?

Hazardous areas are classified into zones based on the probability and duration of an explosive atmosphere being present:

• **Zone 0**: Explosive atmosphere present continuously or for long periods (gases)
• **Zone 1**: Explosive atmosphere likely to occur in normal operation
• **Zone 2**: Explosive atmosphere not likely in normal operation but may occur in abnormal conditions
• **Zone 20/21/22**: Equivalent zones for combustible dusts

Equipment Categories

ATEX equipment is grouped into categories 1, 2, and 3, corresponding to the level of protection provided. Category 1 equipment provides the highest protection and is suitable for Zone 0/20 use.

Valve Selection for Hazardous Areas

When selecting valves for ATEX zones, consider:

1. 1**Actuator ATEX rating** — the actuator, limit switch box, and solenoid valve must all carry the appropriate ATEX certification
2. 2**Non-sparking materials** — valve body and trim materials must not generate static or spark
3. 3**Earthing provisions** — anti-static devices (ISO 7121) prevent static charge build-up
4. 4**Temperature class** — ensure maximum surface temperature is below the ignition temperature of the explosive mixture

AIRA supplies complete ATEX-certified valve automation packages with actuators, solenoid valves and limit switch boxes, all certified to ATEX II 2G/2D as standard, with Category 1 available on request.