On the selection of explosion protection ratings for instruments on tanks with explosion hazards
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Recently, I was involved in the design of a liquor factory, and regarding the selection of the explosion-proof rating for the instruments used on liquor storage tanks, I have some questions. I would appreciate it if experts could discuss these issues: According to Article 9.1.8 of the \"Code for Fire Protection Design of Liquor Factories\" (GB50694-2011), the electrical design of workshops for brewing liquor using liquid methods, alcohol distillation towers, brandy distillation workshops, liquor storage areas with an alcohol content of 38 degrees or higher, artificial cave-based liquor storage areas, edible alcohol storage areas, brandy aging areas, as well as workshops for blending liquor and brandy, filling workshops, and liquor pump rooms, as well as those for fermenting yellow rice wine using distillers’ grains or sorghum wine instead of water for brewing, must comply with the relevant regulations for explosive gas environments in Zone 2； The electrical design of bulk grain silo-type warehouses with a high degree of mechanization and large annual turnover, as well as grain silos and working towers, and raw material crushing workshops, shall comply with the relevant regulations for Zone 11 involving flammable non-conductive dusts. According to this specification, for baijiu storage facilities, instruments can be selected based on Zone 2 of explosive gas environments; in Zone 2, flameproof instruments and intrinsically safe instruments can be used. But I still don’t fully understand the regulations related to explosion hazards. Can the instruments that are in direct contact with the medium, such as those for measuring pressure, flow rate, and liquid level on the liquor tanks and pipelines, be classified as intrinsically safe instruments suitable for Zone 2? Mainly, owners are currently trying to reduce investment costs. The cost of using intrinsically safe instruments together with safety barriers and intrinsically safe cables may be higher than that of flameproof instruments. By the way, I would like to ask experienced experts: what is the approximate price difference between instrument assemblies built using intrinsically safe technology and those using flameproof technology? ), please share your opinions; thank you!
1. If what you say is true, intrinsically safe explosion-proof instruments can all meet the requirements for Zone 2 gases. 2. Price is the hardest to compare generally. For quite standard instruments, I believe that in general, explosion-proof instruments are cheaper to install. Intrinsic safety won’t be much more expensive either. Regardless of the explosion-proof type used, it is advisable to purchase products from domestic brands and carry out construction in accordance with standards.
No one is coming to step on it; I’ll hold it myself
It is fine to use flameproof instruments in Zone 2 of explosive gas environments. Just carry out the construction and installation in accordance with the specifications.
Intrinsic safety meters are hassle-free. Many intrinsically safe instruments also come with heavy explosion-proof enclosures; it’s just that most instrument manufacturers are too lazy to go the extra mile and refrain from obtaining explosion-proof certification for those enclosures. :lol