What is the Division System?
• Division 1 – A location where an explosive mixture of gas, vapor, dust fibers or flyings and air may exist under normal operating conditions. Division 2 – A location where an explosive mixture of gas, vapor, dust, fibers or flyings and air may exist under abnormal conditions. Designation of flammable substances within the Divisions is accomplished via Classes. Class I is for gas/vapor, II is dust and III is ignitable fibers and flyings. The concern for sewers is Class I Division 1 or Class I Division 2. The Division system was originated to allow us to classify hazardous locations in a uniform manner throughout the US (and the world). Those trained in classifying will use the same methodology for an oil refinery and a sewer. A good example of classification would be a Dry Well. This is a portion of a pumping station that is segregated from the rest of the site and is used for housing pumps, motors valveing etc. Under normal conditions this location would be classified a Class I Divis
