Valves in explosive atmospheres: understanding ATEX regulations

Explosive atmospheres pose significant risks in industrial environments where flammable gases, vapours, or dusts are present.

To prevent accidents and ensure operational safety, it is crucial to use valves and equipment certified according to the ATEX regulations.

In this article, we explain in detail what these regulations entail and how they influence the selection of industrial valves for hazardous environments.

The ATEX regulations correspond to the European Directive 2014/34/EU. They establish mandatory requirements for all equipment and systems intended for use in potentially explosive atmospheres. These regulations affect manufacturers, installers, and end users of industrial equipment situated in environments with explosion risks.

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ATEX-certified equipment ensures it is designed and manufactured to eliminate ignition sources such as sparks or high temperatures, significantly reducing the risk of explosions and enhancing overall operational safety.

ATEX zones are classified according to the likelihood and frequency of explosive atmospheres occurring. There are three main categories:

• Zone 0: Areas where an explosive atmosphere composed of gases, vapours, or mists is present continuously, for long periods, or frequently. This continuous risk requires the most rigorously certified equipment.
• Zone 1: Areas where an explosive atmosphere can occasionally form during normal operations. Equipment must be certified to resist ignition and prevent explosions.
• Zone 2: Areas where explosive atmospheres are rare and persist for short periods only. Nonetheless, certified equipment is required to ensure adequate protection against accidental explosions.

Valves intended for use in ATEX zones must meet specific criteria to ensure safety in these potentially hazardous environments:

• Specialised Construction: Valves must be manufactured from special materials and construction methods that eliminate any risk of generating sparks or high temperatures during operation, ensuring they do not become ignition sources.
• Thermal Resistance: It is essential that valves can withstand both ambient and elevated process temperatures, minimising fire and explosion risks.
• Preferred Pneumatic Actuation: Pneumatic actuators are preferred over electrical actuators as they significantly reduce the risk of sparks or hotspots that could ignite explosive atmospheres.
• Clear ATEX Marking: Each valve intended for ATEX zones must have a clearly visible, durable label indicating its specific ATEX certification, including details such as category, zone of use, and safe operating conditions.

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Valfonta offers a range of valves certified or adaptable to comply with ATEX standards, ensuring safety and reliability in potentially explosive environments:

• C1: Pneumatic control valve certified for ATEX zones 1 and 21, specifically designed for precise pressure regulation in critical industrial processes.
• S1, S2, S3: Pressure relief valves suitable for explosive atmospheres, safely relieving pressure in the presence of flammable gases or vapours.
• PRV20, PRV30, PRV44, PRV45, VD, M1, M2, M2+Bellows: Robust, self-acting or balanced pressure reducing valves, customisable on request to meet ATEX requirements and suitable for various industrial applications.

Each valve certified for use in ATEX zones must be accompanied by specific documentation to ensure correct use:

• Declaration of Conformity: A document confirming compliance with ATEX regulations.
• Specific Technical Manual: Clearly details installation, operation, and maintenance instructions in explosive environments.
• Notified Body Certificate: Essential for equipment requiring external verification.
• Visible Labelling on Valve: Clearly identifies certification and usage conditions.

Pressure relief valve S3

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At Valfonta, we offer specialist technical advice to help select the most suitable valve according to your specific system requirements: working pressure, fluid type, temperature, chemical compatibility, and regulatory compliance (ATEX, PED, CE).

Our team of engineers can assist you through all project stages, from initial design or system upgrades to commissioning, integration with other system components, and preventive maintenance. We also provide custom solutions if your installation requires a specially designed valve.

Contact us without obligation by phone (+34) 93 372 08 88, via email at valfonta@valfonta.com, or through our contact form.

Trust Valfonta’s expertise to enhance the safety, reliability, and efficiency of your industrial installation.