Ignition sources equipment safety

Equipment Failures Safety system Ignition Sources Furnaces, Flares, Incinerators, Vehicles, Electrical switches. Static electricity, Hot surfaces. Cigarettes Human Failures Omission, Commission, Fault diagnosis. Decisions Domino Effects Other containment failures. Other material release External Conditions Meteorology, Visibility... 

Equipment safety tries to measure the possibility that a piece of equipment is unsafe (Heikkila and Hurme, 1998a). Here equipment includes all major pieces of equipment such as pumps and vessels etc. but not piping, valves or instruments as separate entities. Equipment safety considers the safety of the equipment as such without interactions through the process with other equipment. This latter aspect is described by the safe process structure (Ch. 7.9). However interactions through layout, such as a furnace can be a source of ignition for a leak from other piece of equipment, are considered by the equipment safety. 

The overall intent of electrical area classification is to provide for safety of personnel and equipment. This is achieved by the elimination of electrical ignition sources near combustible gases or vapors that could explode or bum. The specific reasons for classifying facilities into electrical hazardous areas typically are ... 

Precautions Ammonia gas is very toxic and poses an explosion hazard, particularly in improper storage conditions. Unprotected industrial workers should avoid all contact with ammonia gas and use of contaminated equipment. Ammonia gas should be stored in a cool, dry, well-ventilated area, out of direct sunlight, away from heat and ignition sources, and away from flammable material. Always use chemical safety goggles, a face shield for skin protection, chemical protective gloves, coveralls, boots, and/or other chemical protective clothing. 

Other Ignition Sources Hazardous classification of locations for electrical installations is covered in Articles 500-504 of the National Electrical Code (NEC) (NFPA 70). Proper hazardous classification is essential for safety and for prevention of explosion and fire losses. Class 1 in the NEC is for vapors and gases in the United States, in brief. Division 1 of Class 1 includes those locations where flammable concentrations exist continuously or frequently. Division 2 includes locations where flammable concentrations may exist only in case of accidental escape of vapors or gases, or in case of abnormal operation of equipment. Static electricity, which causes fires and explosions with flammable vapors and gases, is covered later in Sec. 26. Cither ignition sources include friction and impact plus rubbing with rubbing... 

Many of these ignition sources can be controlled through effective housekeeping, equipment maintenance, hot work permit, and general safety programs. Only some of the ignition sources are discussed in greater detail in this entry. 

Fire and explosion hazard in dryers imposes extra requirements on plant maintenance. It is important to apply the general policy in a breakdown case or prevention measures as well as routine maintenance and turnaround periods. Special attention should be paid to maintenance in all safety systans and in that equipment responsible for the ignition sources. A work permit should be followed in all maintenance work, especially performing hot work like welding, cutting, or soldering. 

Safety concerns over ignition sources in flammable atmospheres exist in mai woik environments. Failure to provide intrinsicalfy safe equipment has led to disasters in a wide range of industries and environments, such as mining, space, hospitals and mills to name a few. The prime considerations with equipment used in flammable or explosive atmospheres is the nature of the risk and the level of exposure. 

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