Cov pawg kev nyab xeeb, tau teev tseg los ntawm National Electric Code (NEC), qhia txog kev tiv thaiv ntawm ntau yam khoom siv hais txog cov tshuaj lom neeg lossis cov xwm txheej tshwj xeeb.
Dab tsi yog kev faib tawm uas yog pov thawj tawg?
Cov cuab yeej siv ntawm qhov chaw ua haujlwm flammable yog categorized los yog pab pawg raws li nws cov pov thawj tawg. Cov pawg kev nyab xeeb, tau teev tseg los ntawm National Electric Code (NEC), qhia txog kev tiv thaiv ntawm ntau yam khoom siv hais txog cov tshuaj lom neeg lossis cov xwm txheej tshwj xeeb.
Classifications rau explosive resistance
• Chav Kawm I: Cov xwm txheej uas muaj hluav taws kub thaum muaj cov pa hluav taws xob txaus thiab/lossis vapors tuaj yeem ua rau hluav taws kub.
• Chav Kawm II: Cov chaw uas muaj hluav taws kub uas muaj qhov tseem ceeb ntawm cov khoom siv hluav taws xob thiab/lossis cov plua plav nplaim taws uas tuaj yeem ua rau hluav taws kub.
• Chav Kawm III: Cov xwm txheej uas muaj cov nplaim hluav taws txaus los yog ya mus ua kom muaj hluav taws kub.
Faib ib thiab ob
Division 1 thiab Division 2 muaj peev xwm faib rau cov chav kawm no. Lub Division 1 rated facility yog ib qho chaw uas cov khoom sib txuas uas muaj hluav taws xob tuaj yeem nyob hauv huab cua thaum lub sijhawm ua haujlwm niaj hnub (lub ntsiab lus "explosion proof" yog siv).
Cov chaw uas tswj, txheej txheem, lossis haus cov kua dej los yog cov pa roj uas lawv muaj nyob rau hauv lub sijhawm ua haujlwm raug cais raws li Division 2 cov chaw ntsuas (qee zaum hu ua qhov chaw txaus ntshai).
Pawg
Cov ntaub ntawv pov thawj tawg tuaj yeem suav nrog Pawg ntxiv rau Chav Kawm I, II, thiab III kev ntaus nqi thiab Division 1 thiab Division 2 kev ntaus nqi.
- Acetylene yog nyob rau hauv Group A.
- Hydrogen yog nyob rau hauv pab pawg B.
• Pawg C: Vapors ntawm ethylene thiab ethyl ether
• Pab pawg D: Cawv, Butane, Benzol, thiab roj av
• Pawg E: Magnesium thiab Metallic Dust
• Pab pawg F: Carbon Dub thiab Coal
• Pawg G: Cov nplej thiab hmoov nplej hmoov nplej
Yog hais tias chav kawm thiab pab pawg yog tib yam, ib qho khoom siv hauv Division 1 yuav raug siv nyob rau hauv Division 2 rated cheeb tsam, tab sis tsis yog lwm txoj hauv kev. NEC thiab OSHA muaj txoj cai nyob hauv Tebchaws Meskas, yog li cov ntaub ntawv pov thawj tawg tau siv tau ntawm no thiab. Cov cai tswj kev nyab xeeb hauv zos, xws li ATEX / IECEx cov cai, yuav tsum ua raws li cov chaw txawv teb chaws.
