Fires, accidental equipment

Unattended operations must be planned with automatic safety switches that prevent serious damage (fire, flooding, explosion) in case of accidental equipment failure or interruption of utility services such as electricity, water, or gas supplies. Of special concern are the constant flow of cooling water and the operation of high-temperature baths. In the case of water flow, a device should be installed in the water line to (1) automatically regulate the water pressure (so as to avoid surges that might disconnect or rupture a water hose), and (2) automatically turn off electrical connections and water-supply valves in case of a total loss of water supply. In the case of hot thermostat baths or ovens, a sensor/control device should be installed that automatically turns off the electrical power to all heaters if the temperature exceeds some preset upper limit. 

It is our intent to assure the reliability of fire protection equipment and equipment and systems installed on heat-producing equipment to prevent the accidental ignition of combustible materials. The following employees are responsible for maintaining equipment and systems installed to prevent or control sources of ignition or fires ... 

Process Safety A discipline that focuses on the prevention and mitigation of fires, explosions, and accidental chemical releases at process facilities. Excludes classic worker health and safety issues involving working surfaces, ladders, protective equipment, etc. 

The equipment and systems of the processing phuit are designed to contain tlie chemicals mider processing conditions and to provide tlie controlled environment required for production. This equipment is designed to function under both specific process conditions and upset conditions. Upset conditions tliat are considered in design include fire, explosions, and accidental chemical releases. 

Protection of fired equipment (heaters, furnaces) against accidental explosion and fire. 

The extraction of the common metals from their ores in antiquity was based mainly on relatively simple equipment and processes. Lumps of copper or iron ore, for example, that may have formed part of a ring of stones around an ancient domestic fire and become embedded in its embers, could have been reduced to metal. It is quite reasonable to conjecture, therefore, that some prehistoric campfire became, quite accidentally, the first metallurgical furnace. All that is needed to convert a campfire into a smelting furnace is a small depression in the ground to receive the molten metal. A furnace of this type is illustrated in Figure 42 (Gowland 1912 Killick 2001). 

The nonelectric firing system is simple and requires a minimum of equipment. Once initiated, however, it passes from the control of the operator. The electric system can be retained in the control of the operator up to the actual firing. Electric caps also are more waterproof. On the other hand,-the electric system is more complicated, employs more equipment, and may require the operator to remain near the scene at the time of firing. In addition, electric systems can be accidentally activated by static electricity and are hazardous to use in some target situations. 

Hazardous substances present in the process are identified on the basis of their flammability, explosiveness and toxicity. The flammability of gases and vapours of flammable liquids is a great concern in the process industries. The result of an ignition can be a fire or an explosion or both. Accidental fires and explosions of flammable mixtures with air often follow the escape of combustible materials or inlet of air into process equipment. 

Failures can either be fail-safe or fail dangerously. Fail safe incidents may be initiated by spurious trips that may result in accidental shutdown of equipment or processes. Fail dangerously incidents are initiated by undetected process design errors or operations, which disable the safety interlock. The fail dangerously activation may also result in accidental process liquid or gas releases, equipment damage, or fire and explosions. 

Personal Protective Equipment — The items are those recommended by (a) manufacturers, either in technical bulletins or in Material Safety Data Sheets, (b) the Manufacturing Chemists Association, or (c) the National Safety Council, for use by personnel while responding to fire or accidental discharge of the chemical. They are intended to protect the lungs, eyes, and skin. 

Critical Consequence Class 1. Containment equipment or the critical instruments serving that equipment whose failure would result in uncontrolled releases of dangerous materials, situations resulting in accidental fires or explosions, reportable environmental releases including closing of nearby highways or shelter in place for community members, personal injury, death, or major property or major production loss. 

Serious Consequences—Class 2. Equipment or the critical instruments serving equipment whose failure could possibly cause, or fail to warn of upset conditions, uncontrolled releases of dangerous materials, situations that could result in accidental fires and explosions. Furthermore these failures could result in serious conditions involving environmental releases, property or production losses, or other non-life-threatening situations. These particular pieces of equipment, the safety shutdown systems and the alarms that serve this equipment are given a slightly lower priority. However, they are also inspected, tested, or prooftested on a regular schedule, but may be allowed to have some leniency in compliance. 

Many of the countries that formerly produced PCBs, except Russia, ceased production in the 1970s however, PCBs remain in the environment for decades, where they are available for uptake and subsequent bioaccumulation in organisms. Before their ban PCBs had entered the environment through point and diffuse sources, such as from landfill sites, accidental spillages/releases during commercial use of electrical equipment and transformer and capacitor fires, incineration of PCB waste, etc. [24, 28, 29]. Leakage from old equipment, building materials, stockpiles and landfill sites continue to supply the environment. In addition, some production has been reported for certain countries with economies in transition [30, 31]. 

The State Police report quoted a refrigeration serviceman who reported that all of the valves on the evaporator were shutoff and the fire chief found a steam hose steaming underneath the machine. The serviceman had previously seen steam used to melt ice buildup around the valves and to heat the oil in the machine to make it easier to drain the oil. [ 51 The District Engineering Inspector s report confirmed that the machine was completely isolated and the ammonia system was not protected by a safety valve or any type of pressure-relief device. The cause of the accident was the presence of the steam ho.se underneath the equipment to melt the ice on the drain valve or to help evacuate the system. The inspector s report could not determine if these preparations were intentional or accidental. 151... 

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... 

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