API Publishes 4th Edition of Standard for Classification of Locations

api 500API 500 Series · API 550A 500 Series 3-band Equalizer · API 550b 500 Series 4-band Equalizer · API 500-6B 6-slot 500 Series Lunchbox · API 500V 10API RP 500 defines two types of divisions: Division 1: An area in which nitable concentrations of flammable gases, vapors, or liquids