A "hot surface" is one of the most critical potential ignition sources in hazardous environments. The maximum surface temperature of equipment or protective systems is a crucial parameter when selecting gear for these areas. This information must be included in the Ex-marking of ATEX equipment.
When dealing with gas, vapor, or mist atmospheres, the maximum surface temperature (indicated by temperature class or in °C, or both) must include a safety margin relative to the minimum ignition temperature (Tig). This safety margin is determined in accordance with EN 1127-1 and EN 13463-1 standards.
Temperature Classifications and Codes
To help with equipment selection, explore the interactive table below, which includes both ATEX and North American codes:
| Max surface temp. (°C) | ATEX code | American code | Recommended when Tig (°C) |
|---|---|---|---|
| 450 | T1 | T1 | >450 |
| 300 | T2 | T2 | >300 |
| 200 | T3 | T3 | >200 |
| 135 | T4 | T4 | >135 |
| 100 | T5 | T5 | >100 |
| 85 | T6 | T6 | >85 |
Hover over or tap a row to see the temperature visualized!
For example, if you're working with a gas that has a minimum ignition temperature (Tig) of 220°C, you should select equipment with a maximum surface temperature of 215°C. This would be indicated by the ATEX code T2, supplemented with the specific temperature value, or by the American T2D code. Of course, equipment classified in a higher temperature class (e.g., T3 or T4) would also be suitable.
Important Note:
For equipment with a maximum surface temperature exceeding 450°C, only the specific temperature value should be specified in the marking. Equipment designed for use with a particular gas in Group II G doesn't require temperature specifications.
This information complements our existing knowledge about ATEX zones and temperature classifications. By understanding these details, we can ensure that the ATEX-certified equipment we choose is not only compliant but also optimally safe for the specific hazardous environment in which it will be used.
Dust Environments: A Different Temperature Challenge
Group II D Equipment
For equipment used in dust atmospheres (Group II D, categories 1, 2, and 3), temperature considerations take a different approach. Instead of temperature classes, the actual maximum temperature value is typically stated.
When selecting equipment for dust environments, it's crucial to compare the indicated/marked maximum temperature (Tmax) with two key factors:
- The dust cloud minimum ignition temperature (Tig)
- The dust layer minimum ignition temperature (indicated by Tlig or Ts)
Both of these temperatures must be adjusted by an appropriate safety margin for optimal protection.
Scenarios for Dust Ignition Prevention
| Scenario | Condition | Equation | Description |
|---|---|---|---|
| Scenario 1: No Dust Settlement | Dust cannot settle and ignition by smouldering can be excluded | Tmax ≤ 2/3 Tadig | Tadig is the adjusted minimum dust cloud ignition temperature |
| Scenario 2: Dust Settlement Possible | Dust can settle (max 5 mm dust layer) | Tmax ≤ Tadlig - 75°C | Tadlig is the adjusted dust layer minimum ignition temperature; Tlig,5mm is the minimum ignition temperature for a 5 mm dust layer |
Important Note:
For environments where dust layers can be deposited, equipment must comply with both equations to ensure maximum safety.
Special Considerations for Thick Dust Layers
When dealing with dust layers thicker than 5 mm, extra precautions are necessary. The ignition temperature of dust layers decreases as their thickness increases, requiring a larger safety margin.
⚠️ For dust layers exceeding 5 mm, consult with safety experts to determine the appropriate safety margins and equipment specifications.
The "TX" Marking
In some cases, the maximum surface temperature of equipment depends not on the equipment itself, but mainly on operating conditions. In such instances, the equipment is marked with "TX", indicating that:
- The relevant maximum temperature cannot be marked by the manufacturer
- Additional information about temperature considerations is provided in the equipment instructions
Understanding these temperature considerations is crucial when selecting and using ATEX-certified equipment in hazardous environments. By following these guidelines and using proper equipment, you can significantly reduce the risk of temperature-related incidents and ensure a safer working environment.
Key Takeaway
Whether dealing with gas, vapor, mist, or dust environments, temperature management is a critical aspect of safety in hazardous areas. Always consult the equipment specifications, adhere to safety standards, and when in doubt, seek expert advice to ensure the utmost safety in your operations.
Applying Temperature Considerations in Real-World Scenarios
Practical Application Example
Let's explore how these temperature considerations apply in a real-world scenario, using our ATEX-certified products as examples.
Case Study: Oil Refinery Equipment Selection
Imagine you're tasked with selecting equipment for an oil refinery where the ambient temperature can reach up to 40°C (104°F). The specific area you're equipping has been classified as Zone 1, with a gas present that has a minimum ignition temperature (Tig) of 220°C. This scenario presents a complex challenge that requires careful consideration of multiple factors to ensure safety and compliance.
Equipment Selection Process
-
Identify the Required Temperature Class:
Referring to our temperature classification table, we see that for a Tig of 220°C, we need equipment with a T2 rating or higher. Here's why:
- T2 rating allows for a maximum surface temperature of 300°C
- This provides a safety margin of 80°C (300°C - 220°C) above the gas's ignition temperature
- T3 or higher ratings would also be acceptable, as they have lower maximum surface temperatures
-
Select Appropriate Equipment:
Let's consider our ARMADEX Ex-M OZC 2 Explosion Proof Camera. This camera is an excellent choice for several reasons:
- Certified for Zone 2, which exceeds our Zone 1 requirement, providing an extra layer of safety
- ATEX certified, ensuring compliance with European standards for equipment in explosive atmospheres
- Features a 5x optical zoom, allowing for detailed inspections without needing to get too close to potentially dangerous areas
- Robust construction with the ability to withstand drops of up to 2.1m, crucial in industrial environments
-
Verify Temperature Specifications:
The camera's specifications indicate it can operate in temperatures from -40°C to +70°C. This range is suitable for our application because:
- It comfortably accommodates our ambient temperature of 40°C
- Provides a buffer for potential temperature fluctuations
- Allows for operation even if refinery temperatures temporarily exceed typical levels
However, it's crucial to note that this is the operating temperature range, not the maximum surface temperature. We need to ensure the camera's surface temperature doesn't exceed the T2 rating (300°C) under any circumstances.
-
Consider Additional Factors:
Several other factors need to be taken into account:
- Heat generation during operation: Electronic devices generate heat when operating. We need to account for this additional heat to ensure the camera's surface temperature stays within safe limits.
- Exposure to direct sunlight: In an outdoor refinery setting, direct sunlight can significantly increase surface temperatures. Consider if additional shielding or cooling might be necessary.
- Proximity to heat sources: The camera's placement relative to hot equipment or processes in the refinery could affect its temperature. Ensure adequate distance or insulation from these heat sources.
- Duration of operation: Continuous operation might lead to heat buildup. Consider implementing operational procedures that allow for cooling periods if necessary.
- Maintenance and monitoring: Regular temperature checks and maintenance should be scheduled to ensure the camera continues to operate within safe temperature limits.
Additional Considerations
- Power supply: Ensure that the power supply for the camera is also appropriately rated for the hazardous area.
- Cabling: All cabling should be suitable for use in Zone 1 and capable of withstanding the environmental conditions.
- Mounting: The mounting system should be non-sparking and not compromise the camera's explosion-proof properties.
- Training: Operators should be trained on the proper use and maintenance of the equipment in this hazardous environment.
Addressing Dust Environments: Storage Solutions
Now, let's consider a scenario involving a dusty environment, such as a grain storage facility. Here, we need to account for both airborne dust and potential dust layer accumulation.
Scenario Parameters:
- Environment: Grain storage silo (Zone 22)
- Dust cloud ignition temperature (Tig): 400°C
- 5mm dust layer ignition temperature (Tlig,5mm): 250°C
Solution:
Our ATEX Hazardous Substances Container would be an excellent choice for storing equipment or materials in this environment. Here's why:
- It's designed to maintain a stable internal environment
- It can be equipped with temperature control systems to ensure the internal temperature stays well below ignition temperatures
- Its sealed nature prevents dust accumulation on stored items
Monitoring and Communication in High-Temperature Zones
In areas where high temperatures are a constant concern, reliable monitoring and communication equipment is crucial. This is where our temperature-resistant imaging and communication devices come into play.
FLIR Cx5 Thermal Imaging Camera
- Operates in temperatures from -10°C to 50°C
- Ideal for identifying hot spots and potential equipment failures
- Ensures safety by detecting temperature anomalies before they become critical
Bartec Pixavi Phone
- Rugged design for harsh environments
- Ensures reliable communication in high-temperature areas
- ATEX-certified for use in potentially explosive atmospheres
Frequently Asked Questions
Why is ATEX certification important for temperature-sensitive equipment?
ATEX certification ensures equipment is safe to use in potentially explosive atmospheres, including those with temperature-related risks. It guarantees the equipment won't cause ignition due to high surface temperatures or electrical sparks.
How do temperature classes (T1-T6) affect equipment selection?
Temperature classes show the maximum surface temperature allowed for equipment, helping you choose the right tools for specific hazardous environments. For example, T6 equipment (max 85°C) is good for environments with very low ignition temperatures, while T1 (max 450°C) is for less sensitive areas.
Can ATEX-certified devices work in extremely cold or hot environments?
Yes, many ATEX-certified devices are designed to work in a wide range of temperatures. Always check the specifications for each device. Some equipment can handle temperatures as low as -40°C or as high as 200°C.
What should I look for in explosion-proof cameras for high-temperature areas?
Look for ATEX certification, high temperature resistance, strong build quality, and features like optical zoom for detailed inspections. Also consider cameras with thermal imaging to identify hot spots and potential hazards.
How often should temperature-resistant equipment be checked and maintained?
Regular inspections should be done at least once a year, but more frequent checks may be needed depending on the environment and usage. Some high-risk environments might require monthly or even weekly inspections to ensure continued safe operation.
Are there special storage requirements for temperature-sensitive hazardous materials?
Yes, temperature-sensitive materials often need climate-controlled storage, like our ATEX Hazardous Substances Container. These storage solutions should keep a stable internal temperature and have monitoring systems to alert staff of any temperature changes.
How does proper ventilation help manage temperatures in hazardous areas?
Proper ventilation helps maintain safe temperatures, remove potentially explosive vapors, and ensure a safe working environment. It's crucial for getting rid of heat from equipment and preventing the buildup of hazardous gases or dust that could ignite at high temperatures.
How are intrinsically safe smartphones different from regular smartphones in terms of temperature resistance?
Intrinsically safe smartphones are designed to work safely in extreme temperatures and potentially explosive atmospheres, unlike regular smartphones. They often have special cooling systems, temperature-resistant parts, and are certified to work within specific temperature ranges without risk of ignition.
Which industries benefit most from temperature-resistant ATEX-certified equipment?
Oil and gas, chemical processing, mining, and pharmaceutical industries often need temperature-resistant ATEX-certified equipment. These industries frequently deal with extreme temperatures, volatile substances, and potentially explosive atmospheres, making specialized equipment essential for safe operations.
How is Specifex addressing the changing needs for temperature management in hazardous environments?
Specifex continually updates its product range, incorporating the latest technologies and following the most current safety standards. We invest in research and development to create new solutions that address the unique temperature challenges faced by our clients in various industries.
Conclusion: Mastering Temperature Management in Hazardous Environments
Understanding and applying temperature considerations in hazardous environments is crucial for maintaining safety and operational efficiency. By carefully selecting ATEX-certified equipment that meets the specific temperature requirements of your environment, you can significantly reduce risks and ensure compliance with safety standards.
Key Takeaways:
- Always consider both gas/vapor and dust ignition temperatures when selecting equipment
- Use temperature classifications (T1-T6) to guide equipment selection in gas/vapor environments
- For dust environments, consider both cloud and layer ignition temperatures
- Regularly inspect and maintain equipment to ensure it continues to meet temperature requirements
- Invest in specialized monitoring and communication tools for high-temperature zones
At Specifex, we're committed to providing top-quality ATEX-certified solutions that meet the unique challenges of temperature-sensitive areas. From storage containers to communication devices, our range of products is designed to keep your operations running smoothly and safely, no matter the temperature extremes you face.
Remember, when it comes to hazardous environments, choosing the right equipment is not just about following rules—it's about ensuring the safety of your team and the integrity of your operations. Trust Specifex to provide the temperature-resistant solutions you need for your challenging work environments.
