ATEX Explosion Protection
Wherever a small spark or a hot surface can lead to a serious explosion, comprehensive explosion protection for machinery and systems is indispensable. Norgren offers ex proof solenoids under our Buschjost and Herion brands for environments such as these. They have proven themselves in practice many times and are almost universally applicable in explosive atmospheres.
What is an Explosive Atmosphere?
Explosive atmospheres (Ex areas) can be found where a mixture of Flammable gases, vapours and/or dust are stored in the presence of oxygen. Hot surfaces, flames and sparks can all serve as ignition sources in these explosive atmospheres; the ATEX directive seeks to prevent the generation of these ignition sources.
A potentially explosive atmosphere is not strictly limited to the most obvious of workplaces such as oil and gas refineries or refuelling centres, even workplaces such as spray paint booths or workplaces handling fine dust such as quarries or grain and feed mills, may contain or have activities that could potentially create an explosive environment.
ATEX Certification
In order to avoid explosions, or at least control these immediately after they occur, there are numerous standards, laws and regulations that apply to ensure the highest possible level of safety. In Europe the ATEX Directive 2014/34/EU sets the necessary level of safety, while the IECEx Regulations have a more global reach.
The ATEX Directive consists of two EU Certifications concerned with the requirements for equipment and protective systems for potentially explosive environments (including the installation and operation of such systems) as well as setting out the minimum requirements for improving the health and safety of workers potentially at risk from explosive atmospheres.
Hazardous areas are classified into Zones based on if it is a gas or dust atmosphere, the frequency of the occurrence and the duration of an explosive environment occurring. The full ATEX rating also includes hazardous locations classified by types of dust and gas, temperature classes, as well as any special conditions of use.
Zone 0 / 20: Permanent, long-term or frequent
Zone 1 / 21: Forms occasionally in normal operation
Zone 2 / 22: Does not normally occur in normal operation or only briefly
The more hazardous the zone, the more extensive the explosion protection must be. Successive primary, secondary and tertiary protective measures minimise the risk of explosion.
The primary explosion protection prevents the formation of an explosive atmosphere. For example, measures such as the prevention of flammable substances and the limitation of their concentration belong in this area.
Secondary explosion protection concerns preventing existing sources of ignition becoming active in order to prevent the ignition of the atmosphere.
Tertiary explosion protection intervenes when an explosion has already occurred and reduces its effects as far as possible. System depressurisation or the use of pressure-resistant components are suitable protective measures that fall into this category.
Norgren offer an extensive range of certified products for Equipment Group II, Equipment Category 1, 2 & 3 for use in Zones 0, 1 & 2, with a variety of protection methods. This includes ATEX certified solenoid valves, proportional valves and pressure switches.