Hoists Direct sells a variety of explosion proof hoists, cranes and winches that are used in hazardous industrial areas commonly found within manufacturing, power plants and heavy industry. Explosion proof products are used to protect electrical equipment in hazardous locations by enclosing the electrical parts of the product inside the product housing, where every path from the inside of the product housing to the exterior product housing, also known as the flame path, is controlled. If a flammable atmosphere gets inside the product and is ignited by the electrical components, the flame paths will prevent that ignition from being transmitted to the flammable atmosphere outside the product. The outside surface temperature of the explosion proof product also must be controlled so it does not become an ignition source for the outside atmosphere.
The National Fire Protection Association (NFPA) categorizes hazards into 3 classes and 2 divisions. When ordering product, please make sure that the product you select is for the appropriate hazards in your location and always consult with your onsite safety manager with any questions. A summary overview of the classifications and divisions of hazardous areas where hoists, cranes and winches are commonly found is below.
Class I Locations
Class I locations are those in which flammable gases, flammable liquid–produced vapors, or combustible liquid–produced vapors are or may be present in the air in quantities sufficient to produce explosive or ignitable mixtures. Examples of Class I locations include petroleum refineries, petrochemical facilities, aircraft refueling centers, liquid propane gas refueling centers and other misc. gas dispensing areas.
Class I, Division 1
A Class I, Division 1 is a location (1) in which ignitable concentrations of flammable gases, flammable liquid–produced vapors, or combustible liquid– produced vapors can exist under normal operating conditions, or (2) in which ignitable concentrations of such flammable gases, flammable liquid–produced vapors, or combustible liquids above their flash points may exist frequently because of repair or maintenance operations or because of leakage, or (3) in which breakdown or faulty operation of equipment or processes might release ignitable concentrations of flammable gases, flammable liquid–produced vapors, or combustible liquid–produced vapors and might also cause simultaneous failure of electrical equipment in such a way as to directly cause the electrical equipment to become a source of ignition.
Class I, Division 2
A Class I, Division 2 location is: (1) in which volatile flammable gases, flammable liquid– produced vapors, or combustible liquid–produced vapors are handled, processed, or used, but in which the liquids, vapors, or gases will normally be confined within closed containers or closed systems from which they can escape only in case of accidental rupture or breakdown of such containers or systems or in case of abnormal operation of equipment; (2) in which ignitable concentrations of flammable gases, flammable liquid–produced vapors, or combustible liquid– produced vapors are normally prevented by positive mechanical ventilation and which might become hazardous through failure or abnormal operation of the ventilating equipment; or (3) that is adjacent to a Class I, Division 1 location, and to which ignitable concentrations of flammable gases, flammable liquid– produced vapors, or combustible liquid–produced vapors above their flash points 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 II Locations
Class II locations are those that are hazardous because of the presence of combustible dust. Examples of Class II locations include flour and feed mills, grain elevators, coal processing plants and spice manufacturing facilities.
Class II, Division 1
A Class II, Division 1 location is: (1) in which combustible dust is in the air under normal operating conditions in quantities sufficient to produce explosive or ignitable mixtures; (2) where mechanical failure or abnormal operation of machinery or equipment might cause such explosive or ignitable mixtures to be produced, and might also provide a source of ignition through simultaneous failure of electrical equipment, through operation of protection devices, or from other causes; or (3) in which Group E (as defined by the NFPA) combustible dusts may be present in quantities sufficient to be hazardous.
Class II, Division 2
A Class II, Division 2 location is: (1) in which combustible dust due to abnormal operations may be present in the air in quantities sufficient to produce explosive or ignitable mixtures; (2) where combustible dust accumulations are present but are normally insufficient to interfere with the normal operation of electrical equipment or other apparatus, but could as a result of infrequent malfunctioning of handling or processing equipment become suspended in the air; or (3) in which combustible dust accumulations on, in, or in the vicinity of the electrical equipment could be sufficient to interfere with the safe dissipation of heat from electrical equipment, or could be ignitable by abnormal operation or failure of electrical equipment.
Class III Locations
Class III locations are those that are hazardous because of the presence of easily ignitable fibers or where materials producing combustible material are handled, manufactured, or used, but in which such fibers/material are not likely to be in suspension in the air in quantities sufficient to produce ignitable mixtures. Examples of Class III locations include cotton seed mills, textile mills and wood pulp processing facilities.
Class III, Division 1
A Class III, Division 1 location is location in which easily ignitable fibers/material are handled, manufactured, or used.
Class III, Division 2
A Class III, Division 2 location is a location in which easily ignitable fibers/material are stored or handled other than in the process of production.
This summary is for illustrative purposes only. Please consult the National Fire Protection Association (NFPA) codes and standards with any questions on their classifications, divisions and groups of hazardous areas by visiting www.nfpa.org.