Classification of explosive hazard areas
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Facilities in the light industry sector (carton manufacturing) use small amounts of substances such as isopropyl alcohol and cleaning agents, which fall into Category A; the total amount used is around 50 kg. These substances are currently planned to be stored in explosion-proof cabinets in the workshop, with these cabinets occupying no more than 5% of the workshop’s space. The fire hazard category of the workshop is Category C. I would like to ask whether these explosion-proof cabinets should be considered as sources of ignition, thereby requiring the designation of an explosion-hazard zone in the workshop. My personal opinion: Divide Zone 2 according to secondary release sources. Owner’s view on the use of explosion-proof electrical equipment in explosion-proof areas: Keeping the doors of the explosion-proof cabinets closed can prevent flammable gases from entering or exiting (similar to the function of an explosion-proof wall); thus, the explosion hazard exists only inside the cabinets, and there is no need to demarcate an area outside them. Welcome everyone to discuss; thank you
It doesn’t seem appropriate; flanged valves normally don’t leak either, but they are considered potential sources of leakage. . Similarly, it can’t be assumed that this one won’t leak at all either.
Read GB50058 carefully; it contains descriptions regarding the fact that small quantities of hazardous chemicals do not constitute an explosion hazard zone. This is related to the amount of explosive materials stored and the volume of the building. Check whether your actual situation meets the requirements specified in the standards. If not, explosion prevention measures must be taken
Please also refer to Article 3.1.2 of GB50016-2014 (2018 edition), which specifies the principles for determining the fire hazard level of a building or area when there are production activities with different fire hazards within the same factory building or within the same fire compartment of that building； Please confirm accordingly based on the items stored in your unit! Thank you!