Regarding the classification of explosion-proof areas
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What is the basis for determining explosion-proof zones? For example, when is it necessary to add explosion-proof walls? GB50058, the \"Code for Design of Electrical Installations in Explosive and Flammable Environments\", discusses electrical explosion protection. However, in practice, a broader concept of explosion-proof zones is often encountered; for example, when a certain area is designated as an explosion-proof zone, does that necessarily mean it has explosion-proof walls and doors? ? ? I can’t figure out where it comes from Could someone with more experience give some advice? Thank you
What is the basis for determining explosion-proof zones? For example, when is it necessary to add explosion-proof walls?
It depends on the process medium; it’s determined by the process patent holders, as only they know best
GB50160 and GB50016 can be referred to. Table 3.1.1 Classification of Fire Hazard in Production
Production Category | Characteristics of Fire Hazard
--- | ---
A | 1. Liquids with a flash point below 28°C
2. Gases with an explosion limit below 10%
3. Substances that can decompose on their own at room temperature or oxidize in air, leading to rapid self-ignition or explosion
4. Substances that, when exposed to water or water vapor in the air at room temperature, produce flammable gases that can cause combustion or explosion
5. Strong oxidizers that are highly prone to combustion or explosion when exposed to acids, heat, impact, friction, catalysts, or flammable inorganic substances such as organic compounds or sulfur
6. Substances that can cause combustion or explosion upon impact, friction, or contact with oxidizers or organic compounds
7. Production processes carried out in enclosed equipment at temperatures equal to or above the substance’s own auto-ignition point
B | 1. Liquids with a flash point equal to or above 28°C but below 60°C
2. Gases with an explosion limit equal to or above 10%
3. Oxidizers that do not fall under category A
4. Chemically flammable solid substances that do not fall under category A
5. Oxidizing gases
6. Dust, fibers, or liquid droplets with a flash point equal to or above 60°C, which can form explosive mixtures with air
C | 1. Liquids with a flash point equal to or above 60°C
2. Flammable solids
D | 1. Production processes involving the processing of non-combustible materials, which often generate intense radiant heat, sparks, or flames at high temperatures or in molten state
2. Various production processes that use gases, liquids, or solids as fuels, or that involve burning gases or liquids for other purposes
3. Production processes that involve the use or processing of difficult-to-combust materials at room temperature
E | Production processes that involve the use or processing of non-combustible materials at room temperature
Production Category | Characteristics of Fire Hazard
--- | ---
A | 1. Liquids with a flash point below 28°C
2. Gases with an explosion limit below 10%
3. Substances that can decompose on their own at room temperature or oxidize in air, leading to rapid self-ignition or explosion
4. Substances that, when exposed to water or water vapor in the air at room temperature, produce flammable gases that can cause combustion or explosion
5. Strong oxidizers that are highly prone to combustion or explosion when exposed to acids, heat, impact, friction, catalysts, or flammable inorganic substances such as organic compounds or sulfur
6. Substances that can cause combustion or explosion upon impact, friction, or contact with oxidizers or organic compounds
7. Production processes carried out in enclosed equipment at temperatures equal to or above the substance’s own auto-ignition point
B | 1. Liquids with a flash point equal to or above 28°C but below 60°C
2. Gases with an explosion limit equal to or above 10%
3. Oxidizers that do not fall under category A
4. Chemically flammable solid substances that do not fall under category A
5. Oxidizing gases
6. Dust, fibers, or liquid droplets with a flash point equal to or above 60°C, which can form explosive mixtures with air
C | 1. Liquids with a flash point equal to or above 60°C
2. Flammable solids
D | 1. Production processes involving the processing of non-combustible materials, which often generate intense radiant heat, sparks, or flames at high temperatures or in molten state
2. Various production processes that use gases, liquids, or solids as fuels, or that involve burning gases or liquids for other purposes
3. Production processes that involve the use or processing of difficult-to-combust materials at room temperature
E | Production processes that involve the use or processing of non-combustible materials at room temperature
There is no inherent connection or relationship between explosion-hazardous areas and blast walls. There are few regulations specifying when a blast wall is necessary; provisions regarding blast walls can be found in 3.3.8 of GB50016-2006, 7.0.6 of GB50177-2005, and 5.4.5 of GB50426-2007. Other situations requiring the use of blast walls are determined based on design requirements. There are numerous posts and related information on this forum regarding the classification of explosion-hazardous areas; please refer to them.
Explosion-proof walls are primarily used when the fire separation distance is insufficient, or due to process requirements, such as the use of explosion-proof walls between certain gas filling stations. The classification of explosion-proof areas should be primarily determined in accordance with the Code for Electrical Design in Hazardous Environments due to Fire and Explosion
50058: If you can’t figure it out, take another look, then another look, and yet another look... and then you’ll understand