How to distinguish between fire prevention and explosion prevention? What are the differences?

It is very important to ensure that an item is not easily damaged. But can an object resist the internal force of an explosion? This is where the concept of explosion-proof or flameproof comes into play. This brings up a question: What is the difference between explosion-proof and fireproof? Here are the things to remember.

Flameproof

The term “flameproof” is mainly used in Europe. Generally, it covers the area system certification of hazardous substances for international use only in accordance with IEC guidelines. Either that, or it is certified by a US certification body for use in the United States or Canada. These flameproof products are often suitable for certification with a zone system. Additionally, you may encounter different standards for flameproof.
IEC 60079-1 is a standard that focuses on the technical requirements for the ex – db marking and helps with IEC certification of flameproof. UL 60079-1 is another standard, but it focuses on products that require zone-based certification and is only for use in the United States. CSA C22.2 No. 60079-1 is similar to the previous one, but it is only applicable in Canada.
According to this zoning method, gas groups IIA, IIB, and IIC can be classified. The gases in group IIC are the most flammable.

Explosion-proof

When we talk about explosion-proof items, this mainly focuses on items approved by North American certification bodies. These use a category/division system and they focus on items used only in the United States. When you install any certified system in a hazardous location, it can have its own category and division. Those with Class I and Division I know that explosion-proof protection technology is used.

You will notice that North American standards are created by ANSI, FM, UL and CSA. To obtain Class I and Division, this means you must comply with Canadian CSA C22.2 No. 30 or American UL 1203 standards.

Another important aspect to consider is that all electrical products in the United States must comply with dedicated general safety standards. If you want to obtain hazardous location certification domestically, this is one of the crucial factors. You will encounter different gas groups, from A to D, with D being the least flammable and A being the most flammable.

What are the differences between explosion-proof systems and flameproof systems?

Specification protocol

One of the main differences between explosion-proof systems and flameproof systems is that they follow different protocols. For instance, explosion-proof systems adhere to the NEC protocol. However, flameproof systems are covered by the IEC protocol. Fireproof systems are used in the European Union, while explosion-proof systems are more prevalent in the United States.

Test parameters

Another difference between explosion-proof and flameproof systems lies in the test parameters. Generally speaking, it is known that explosion-proof systems can withstand up to four times the gas explosion pressure. On the other hand, flameproof systems are usually tested for overpressure and other conditions. The pressure they test is approximately 1.5 times the normal pressure, rarely reaching four times the pressure test.

Markings

Explosion-proof markings comply with American standards, focusing on class, division, and group. Each marking has its function, as it indicates the t-class of the device but also the flammability of the gas. At the end of the marking, you will get XP, which indicates that you are using an explosion-proof method.
Flameproof markings, on the other hand, comply with the requirements of the area system certification based on the location. EX will show the hazardous location, while DB focuses on fire protection. Then comes IIC, indicating the gas group. Finally, you will have the temperature class from T1 to T6.

Protection Covers

It is important to remember that the enclosures of explosion-proof and flameproof systems are usually connected to the joint or threaded enclosures, or they are actively bolted. Some flameproof enclosures rely on special tools, and you must start using these tools to disassemble them correctly. This is not an enclosure that you can drill out anywhere. You need to drill it in the factory, while explosion-proof enclosures can be drilled on site.

Can the terms “explosion-proof” and “flameproof” be used interchangeably?

It is well known that flameproof is one of the many explosion-proof technologies. It can be used in motors, JBs, and many lighting fixtures in various known hazardous areas. IEC is the organization that certifies protective equipment. Generally speaking, to obtain flameproof or explosion-proof certification, you must have a housing that can help control all explosion reactions. Most importantly, this protective device needs to be certified and also needs to contain all pressures without having to deal with pressures that spread through distortion or rupture, which can be very problematic.

These two terms can be used interchangeably, even though there are some minor differences. Especially geographical location and local standards often prompt you to use one of the terms. When you use this type of housing, you always want to ensure that they are heat-resistant and can provide good protection for the location from any type of danger that occurs during an explosion.

The main differences between explosion-proof and flameproof systems

As we mentioned earlier, in the case of flameproof systems, they must be drilled by the manufacturer for explosion-proof purposes. Systems for explosion-proofing can be drilled on-site. The structure of explosion-proof systems is heavier, while flameproof systems are much lighter. The joints of both can be flat or threaded, although for explosion-proof systems, they can be serrated, while for flameproof systems, they can be faucet-shaped. For explosion-proof systems, thermal rise is not a consideration, but for flameproof systems, it may be a limiting factor for the overall internal components. The situation for wiring roofs is the opposite; it is a crucial design method for explosion-proof systems, but not as important for flameproof systems.

Conclusion

If you want to ensure compliance with local guidelines and requirements, it is very important to understand what an intrinsically safe system is. Depending on your location, you must use explosion-proof or intrinsically safe solutions. That being said, both are very similar, but there are some subtle differences, such as the high-pressure test or thermal rise of an explosion-proof system not being taken into account, but these are key factors for an intrinsically safe system. Once you understand these differences, it will be easier to accurately determine what such a system is and which one is ideal based on local and functional factors.

Amasly Lighting offers a wide range of Ex “d” explosion-proof and flameproof products, such as junction boxes, to meet your needs in hazardous areas. You can visit our contact page to send an inquiry or call us at +86 13732643699 to learn more about the explosion-proof and flameproof products we provide.