When working in a Hazardous environment, you may have come across an enclosure or two without even noticing it. But what is Class 1, or Division 2. Or better yet, what is a Class 1 Division 2 enclosure?
Class 1 division 2
Let’s define Class 1 Division 2.
Class 1 locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Class I locations are further subdivided into two Divisions and three Zones.
Class I, Division 1: There are three different situations that could exist to classify an area as a Class I, Division 1 location:
- Ignitable concentrations of flammable gases or vapors may exist under normal operating conditions.
- Ignitable concentrations of such gases or vapors may exist frequently because of repair or maintenance operations or because of leakage.
- Breakdown or faulty operation of equipment or processes might release ignitable concentrations of flammable gases or vapors, and might also cause simultaneous failure of electric equipment.
Class I, Division 2: One of the following three situations must exist in order for an area to be considered a Class I, Division 2 location:
- Volatile flammable liquids or flammable gases are handled, processed or used, but the hazardous liquids, vapors or gases will normally be confined within closed containers or closed systems from which they can escape only in the event of accidental rupture or breakdown of such containers or systems, or as a result of abnormal operation of equipment.
- Ignitable concentrations of gases or vapors are normally prevented by positive mechanical ventilation, and which might become hazardous through failure or abnormal operations of the ventilating equipment.
- Adjacent to a Class I, Division 1 location, and to which ignitable concentrations of gases or vapors might occasionally be communicated unless such communication is prevented by adequate positive-pressure ventilation from a source of clean air, and effective safeguards against ventilation failure are provided.
Class 1 Hazardous Locations refer to facilities which deal with flammable gases, vapors, and liquids.
Division 2 specifies that these flammable materials are handled, processed, or used in the defined hazardous location, but are not normally present in concentrations high enough to be ignitable
This applies to devices such as Flashlights, Meter readers, Enclosures, etc.
So a Class 1 Division 2 Enclosure is an Enclosure that is used in facilities which deal with flammable gases, vapors, and liquid materials that are handled, processed, or used in the defined hazardous location, but are not normally present in concentrations high enough to be ignitable