Groups - Honeywell RMA 3000 User Manual

Groups

34
Flammable gases, vapors and ignitable dusts, fibers and flyings are classified into one
of the following groups according to the energy required to ignite the most easily-
ignitable mixture within air.
Class I
Group
A Atmospheres containing acetylene.
B Atmospheres containing hydrogen, fuel and combustible process
gases containing more than 30 percent hydrogen by volume, or gases
or vapors of equivalent hazard
C Atmospheres such as ethyl ether, ethylene, or gasses or vapors of
equivalent hazard.
D Atmospheres such as acetone, ammonia, benzene, butane,
cyclopropane, ethanol, gasoline, hexane, methanol, methane, natural
gas, naphtha, propane or gases or vapors of equivalent hazard.
Class II
Group
E Atmospheres containing combustible metal dusts including aluminum,
magnesium, and their commercial alloys, and other metals of similarly
hazardous characteristics.
F Atmospheres containing combustible carbonaceous dusts including
carbon black, charcoal, coal or other dusts that have been sensitized
by other materials so that they present an explosion hazard.
G Atmospheres containing combustible dusts not included in Group E or
F, including flour wood, grain, and other dusts of similarly hazardous
characteristics.
34-ST-25-19 RMA 3000 Remote Meter Assemblies User Manual
Description of Atmosphere
Description
Release: 1
6/04