Increased safety equipment

Type e equipment, also known as increased safety equipment, employs a protection method to electrical apparatus that does not, in normal operation, produce sparks. Examples are transformers and squirrel cage motors. Type e equipment may be used in Zone 1 areas. 

Increased safety equipment is more akin to ordinary non-explosion-protected designs, but special precautions have to be taken to prevent any electrical or frictional sparking or hot spots exceeding the specified temperature limits. To prevent excessive heating the equipment is liberally rated and under fault conditions the associated control gear has to interrupt the circuit before dangerous overheating occurs. 

The pursuit of product quality over the last few decades has been intense in many companies around the world, but in many sectors of industry, reliability is considered to be the most important quality attribute of the product (Kehoe, 1996). As consumers become more aware than ever of quality, their expectations for reliability are also increasing. Even equipment without obvious safety concerns can have important reliability implications. Most products can, therefore, benefit from the use of sound reliability techniques (Burns, 1994). Reliability prediction, in turn, has the benefit that it gives a quantifiable estimate of the likely reliability that can be assessed to see if this is appropriate for the market (Stephenson and Wallace, 1996). 

The buyers of motor vehicles have been substantially positive concerning the need to have cleaner running vehicles. Although the required emission control devices and other mandated safety equipment have increased the cost of new motor vehicles, sales have not been significantly effected. The current environmental awareness and concern are evidence of the general population s new found knowledge and acceptance of both mobile and stationary source emission controls. 

Over the years the performance standards of hydraulic equipment have risen. Whereas a pressure of about 1000 psi used to be adequate for industrial hydraulic systems, nowadays systems operating with pressures of 2000-3500psi are common. Pressures above 5000psi are to be found in applications such as large presses for which suitable high-pressure pumps have been developed. Additionally, systems have to provide increased power densities, more accurate response, better reliability and increased safety. Their use in numerically controlled machine tools and other advanced control systems creates the need for enhanced filtration. Full flow filters as fine as 1-10 micron retention capabilities are now to be found in many hydraulic systems. 

There can be an element of maintenance that is a fixed and an element that is variable. Fixed maintenance costs cover routine maintenance such as statutory maintenance on safety equipment that must be carried out irrespective of the rate of production. Variable maintenance costs result from certain items of equipment needing more maintenance as the production rate increases. Also, the royalties that cover the cost of purchasing another company s process technology may have different bases. Royalties may be a variable cost, since they can sometimes be paid in proportion to the rate of production or sales revenue. Alternatively, the royalty might be a single-sum payment at the beginning of the project. In this case, the single-sum payment will become part of the project capital investment. As such, it will be included in the annual capital repayment, and this becomes part of the fixed cost. 

The control structure discussed in this section is presented in Figure 4.4(a). The reactor-inlet flow rate is fixed at the value l. Reactor effluent controls the reactor holdup V, while the coolant flow rate controls the reactor temperature. Dual composition control is used for the distillation column. The reactant is fed on level control. For illustration purposes, a buffer vessel was considered. This increases the equipment cost and might be unacceptable due to safety or environmental concerns. An alternative is to feed the reactant in the condenser dram of the distillation column. This strategy achieves the regulation of reactant inventory, because any imbalance is reflected by a change of the holdup. 

It was known that MIC reacts with water to liberate carbon dioxide with the accompanying generation of heat, which causes the pressure in a closed container to increase. MIC can be detoxified by treatment with aqueous caustic soda or by combustion in the air. The storage facility for MIC in Bhopal had safety equipment installed to enable the detoxification of MIC, but the equipment did not work at the time of the accident... 

U = this mark indicates that the certificate is a component certificate for electrical equipment which cannot operate on its own (e.g. cable entries for enclosures in increased safety - e -). 

What is the philosophy of increased safety, or, in other words, what is the difference to normal industrial equipment ... 

Table 6.18 gives a survey of these relations according to IEC 60664-1 for normal industrial equipment compared with the specifications according to IEC 60079-7 and EN 50019 for increased safety - e Figure 6.39 shows creepage distances at a terminal block. 

Basically, process intensification aims at replacing large, expensive, energy-intensive equipments or processes with ones that are smaller, cheaper and more efficient. At the same time, they have to minimize environmental impact, increase safety, improve remote control and automation and ensure a better product quality. 

Another important work duty for a food chemist is to serve on committees that are striving to improve laboratory procedures. There is a constant need to increase safety precautions surrounding food research. If equipment becomes contaminated or you do not observe cleanliness procedures such as washing your hands, your research could become worthless. 

The most common and important trade-off involves specifying liquid holdup volumes in tanks, column bases, reflux drums, etc. From a steady-state viewpoint, these volumes should be kept as small as possible to minimize capital investment and reduce potential safety and pollution problems. For example, the more holdup needed in the base of a distillation column, the taller the column must be. In addition, if the material in the base of the column is heat sensitive, it is very desirable to keep holdup as small as possible to reduce the time that the material is at the high base temperature. Large holdups also increase safety and pollution risks in the handling of hazardous or toxic materials because equipment failures have the potential to release large amounts of material. 

Type e is also called increased safety and intended for apparatus that is to be installed in a Zone 1 area. Two of the allowable features of the type d enclosures, namely permitting sparking components and no Temperature Class hmit to the internal components, cannot be incorporated into the type e designs. The practical aspect of this is the removal of a source of ignition i.e. a spark or a hot surface. In many types of equipment e.g. luminaries, terminal boxes, junction boxes, some designs of motor control stations, telephones and public address speakers, the elimination of these two sources of ignition is not a difficult problem. 

Pay special attention to construct research team, and concentrate the preponderant scientific manpower on tackling safety issues or to improve the safety technology and equipment performance by referencing the experience of international coal mine advanced science and technology. The nation should take active measures to encourage coal mine enterprises to adopt advanced technology and methods, take particular emphasis on basic research of mine gas disaster prevention to control vital coal mine disasters effectively. Increase safety input, ensure special fund for special use and improve the level of technical equipment to enhance the coal mine safety production level. 

The addition of safety equipment to a process may lead to an increase in the number of shutdowns. For example, adding fire eyes to a furnace will improve its safety because they will warn of situations where a burner flame has gone out. However, fire eyes may fail internally, thus leading to spurious alarms and trips. 

Increased safety e (note 1) EN 60079-7 Additional technical measures are implemented in order to prevent with high reliability the possibility of impermissibly high temperatures, sparks and electric arcs inside or outside of an equipment, which do not occur during normal operation. Terminal and junction boxes, control boxes for accommodating Ex devices (which are protected according to a different types of ignition protection), squirrel cage motors, lamps, installation materials, inductive ballasts, transformers... 

These recommendations describe four combinations of practices, safety equipment, and facilities for experiments onanimals infected with agents which produce,ormay produce,human infection. These four combinations provide increasing levels of protection to personnel and to the environment, and are recommended as minimal standards for activities involving infected laboratory animals. These four combinations, designated Animal Biosafety Levels ABSL 1-4, describe animal facilities and practices applicable to work on animals infected with agents assigned to corresponding Biosafety Levels BSLl-4. 

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