What are some hazardous ATEX Ratings

Dependable electronics are an absolute necessity in hazardous environments. However, the combination of combustible gases or dust with an arc or a spark from these products can potentially cause devastating fires or explosions. Whether you are at the chemical plant, on your oil platform or offshore drilling rig, in your mill, or somewhere equally as dangerous, all of your equipment is likely carrying a hazardous rating like Class I Div 2, Class I Div 1, IECEx/ATEX Zone 1 or Zone 2. But what does that mean exactly and how does this affect what lighting you should buy? Read on for more clarity on hazardous environments and ratings.

What is a hazardous location?

Hazardous locations are in more places than you think and it’s important to be aware of them if you are purchasing electronic equipment including LED lighting. Even your local gas/petrol station is considered a hazardous location because of the potential for an explosion. If, for example, a spark or lit cigarette collides with a drop or puddle of gasoline – FIRE! Your gas station needs hazardous-rated lighting.

According to UL (a US-based global certification laboratory), a hazardous location is “where explosion or fire hazards exist due to the presence of flammable gases, flammable or combustible liquid-produced vapors, combustible dust, or ignitable fibers or flyings.”

This could mean anything from the obvious like a drilling rig or chemical plant where highly flammable substances are mined or processed. Or it could mean the less obvious like a mill or sugar processing facility where the minute particles in the air have the potential to create a spark in the right conditions. Each facility is rated differently, based on their potential for explosion, which we’ll dive deeper into below.

What are some of the hazardous UL Ratings?

UL ratings are seen and adhered to most often in North America but do apply to countries in South America, Asia, and the Middle East. When looking at a hazardous UL rating, you’ll find the Class first and then the Division.

Dialight most often sees and certifies Class I, II, and III. The main difference between the three is the presence of flammable gases/vapors; combustible or conductive dust; or fibers like wood chips and cotton (see the chart below). The lower the Class the higher the hazard.

The Division (1 or 2) is what defines the likelihood of there being hazardous substances in enough ignitable concentrations in the atmosphere (i.e. what is the likelihood that there is enough gas or dust in a given situation that it would ignite or explode and what is the circumstance for that). If your facility is Div 1, it means that the particles or gases/vapors created at your facility are always potentially going to ignite and severe caution is needed to prevent a spark (think chemical processing). Div 2 means that an explosion or fire could only happen in the event of some breakdown or system failure but that extreme caution should still be observed to prevent catastrophe (ex. A platform in an oil refinery may be a CI D2 environment as the decks tend to be outdoors and far enough away from the source of the flammable gas. It would only become hazardous if an abnormal condition occurred like a valve failure or similar accident.)

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What are some hazardous ATEX Ratings?

IECEx/ATEX ratings are seen most often in Europe, Australia, and parts of Africa, Asia, and the Middle East. They are relatively similar to UL ratings in that the lower the Zone the higher the probability is for fire or explosion based on the materials present and their concentration in the atmosphere. Both UL and ATEX classify certain substances in groups. Check out our ATEX reference chart below.

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Pressure & Temperature – Rugged Pressure and Temperature Switches for Nuclear Power Stations

  • For pneumatic or hydraulic control, power generation safety equipment and pressurized chambers control
  • Resistant to short duration overpressure
  • and show a good vibration resistance
  • Very good repeatability (±1% F.S.)
  • Comply with ATEX 94/9/CE requirements

With the series ZPN, ZDPN and ZT, Baumer offers very robust pressure and temperature switches developed especially for the use in nuclear power stations. The pressure switches are suitable for pneumatic or hydraulic control, for power generation safety equipment and for pressurized chambers control. They are resistant to short duration overpressure and show a good vibration resistance. The ZPN can measure a gauge pressure from -1 bar up to 600 bar with a very small intermediate range from -2 mbar up to 10 mbar. TheZDPN measures a differential pressure from 2 mbar up to 120 bar.
The pressure switches maintain a constant pressure around a chosen set value. When the pressure reaches a critical pre-set value, they trigger an alarm or safety system. A flexible diaphragm actuates a micro-switch via a piston. The set point adjustment is realized via a compressible spring mounted on the opposite. Due to the force-balance principle, the dead band setting remains constant, even with different setpoint adjustments. With rapid pressure variations, an attenuator should be used to prevent a temporary on and off switching.
The ZT temperature switches are suitable for all fluids and measuring ranges between -45°C and 350°C. They maintain a constant temperature around a chosen set value and act as a regulator of an alarm or safety system when the temperature reaches a critical pre-set value.
The pressure and temperature switches ZPN, ZDPN and ZT offer a very good repeatability (±1% F.S.) making them suitable for all demanding applications. The devices comply with ATEX 94/9/CE requirements for the use in hazardous areas, they are available in an intrinsically safe and an explosion-proof version. Approved by the French electricity board EDF, they are used in nuclear power stations all over the world.