Reactive Maintenance

Interfacing of LANs to WANs Preventative and reactive maintenance... 

Preventive maintenance activities have been recorded as long as 5,000 years ago as part of inspection routines in the pyramids of Egypt. With the development of reliabihty engineering in the 1950s, production companies moved from corrective (or reactive) maintenance to preventive maintenance and in specific scheduled maintenance (or time-based maintenance). 

If item failure proposes no critical effect, reactive maintenance is more cost effective. Various forms of preventive maintenance are standardized according to the European Standard EN 13306 (Fig. 2). 

The use of risk informed maintenance strategies should be considered, to provide a reasonable balance in the mixture of corrective, preventive and predictive maintenance (see paras 2.2-2.4) and to facilitate proactive maintenance rather than exclusively reactive maintenance. 

Idhammar2009 Safety and Reactive Maintenance letneveA atwww.idcon.com/article-reliability-maintenance-reactive. htm 2/2-2009. 

For each item considered in this inventory you must estimate the average length of time before the maintenance work becomes reactive rather than preventive or breakdown. Plan to perform the maintenance before the average time. Review maintenance records periodically to understand how much reactive maintenance (repair or replacement of defective parts after failure) has been done. After the record review, make new estimates of average time, and adjust your maintenance timetable accordingly [2]. 

The period up to around the 1950s (the end of WWII) was referred to as the first generation in maintenance. The feature characteristic for that period was taking up repairs or replacing machines and technical devices only after breakdown happened (so called reactive maintenance). The next generation of maintenance was initiated with the industrialization process. An increased number of machines and devices in companies, and their... 

Reactive maintenance is referred to as many different names, such as breakdown maintenance, repair, fix-when-fail and run to failure maintenance. When applying this maintenance strategy, a piece of equipment receives maintenance (repair or replacement) only when the deterioration of the equipment s condition causes functional failure. The strategy of reactive maintenance assumes that failure is equally likely to occur in any part, component or system. Thus, this assumption precludes identifying a specific group of parts for possible repairs as being more necessary or desirable than others. 

The major downside of reactive maintenance is unexpected and unscheduled equipment downtime. If the equipment fails and repair parts are not available, delays ensue while parts are ordered and delivered. When this is the sole type of maintenance practised, both labour and materials are used inefficiently. Labour resources are thrown at whatever breakdown is most pressing. A purely reactive maintenance programme ignores the many opportunities to influence equipment survivability. However, it can be effective if used selectively and performed as a conscious decision based on the results of an RCM analysis. Equipment that can be reactively maintained must be non-critical and will not pose any serious hazards or affect the operation of the system as a whole. 

Maintenance records should be periodically reviewed for reactive maintenance repair or replacement of defective parts after failure (breakdown maintenance) has been completed. Poor maintenance and poor housekeeping are... 

The service provided by maintenance engineering was traditionally that of repairing equipment items when they failed. This is no longer the case, and a maintenance department is now pro-active rather than reactive in its approach. Maintenance of equipment items will be an important consideration in the FDP, because the mode and cost of maintaining equipment plays an important part in the facilities design and in the mode of operation. 

PhenoHcs that are not heat-reactive may be incorporated into both air-dried and baked oleoresinous coatings. AppHcations vary widely and include clear and pigmented exterior varnishes, aluminum-maintenance paints, 2inc-rich primers, can coatings, insulation varnishes, and concrete paints. As modifiers in a great variety of appHcations, they enhance the performance of oleoresinous and alkyd coatings. 

This part considers reactive power control with the use of shunt and series capacitors. The controls may be manual or automatic through electromagnetic or static devices. Protection of capacitors and capacitor banks as well as design, manufacturing and test requirements, installation and maintenance are also covered, the main thrust being on the application of power capacitors. 

Too little maintenance results in unexpected failures and consequential major losses of production and/or customers (Figure 7-1). This impractical approach is termed reactive strategy and should be avoided on all important machinery. Optimum maintenance strategy balances reasonable costs with maximum possible availability and reliability. The two main maintenance strategies employed by companies today are labelled predictive strategy and preventive strategy. These are part of a balanced approach as shown in Figure 7-2. 

Engineering factors include (a) contaminant characteristics such as physical and chemical properties - concentration, particulate shape, size distribution, chemical reactivity, corrosivity, abrasiveness, and toxicity (b) gas stream characteristics such as volume flow rate, dust loading, temperature, pressure, humidity, composition, viscosity, density, reactivity, combustibility, corrosivity, and toxicity and (c) design and performance characteristics of the control system such as pressure drop, reliability, dependability, compliance with utility and maintenance requirements, and temperature limitations, as well as size, weight, and fractional efficiency curves for particulates and mass transfer or contaminant destruction capability for gases or vapors. 

The heaviest products obtained directly from oil arc lubricants, waxes, asphalt, and coke. These products have both domestic and industrial uses. Lubricants, for example, are applied in the operation and maintenance of industrial equipment and machinery. Asphalt, because it is not reactive to chemicals in the environment, is a superb material of construction in the building of roads and in roofing. It is also used in the waterproofing of concrete, the manufacture of black paints, and as a material lor tire threads, battery housing, electrical insulation, and other applications. The heaviest of all the petroleum products, coke, is used extensively as a major component of industrial electrodes and as a commercial fuel. 

As copper is not an inherently reactive element, it is not surprising that the rate of corrosion, even if unhindered by films of insoluble corrosion products, is usually low. Nevertheless, although the breakdown of a protective oxide film on copper is not likely to lead to such rapid attack as with a more reactive metal such as, say, aluminium, in practice the good behaviour of copper (and more particularly of some of its alloys) often depends to a considerable extent on the maintenance of a protective film of oxide or other insoluble corrosion product. 

Life processes ultimately depend on the transport and reactivity of chemical elements and compounds. Modern biological studies have elegantly unraveled the complicated carbon-based metabolic cycles that are essential to the maintenance of many living things. 

Inherent hazard (e.g., toxicity, stability, reactivity) Cost Renewability Recyclability Size (volume) Scalability Controllability Energy (i.e., total, heating, cooling, recovery, treatment, etc.) Ease of cleaning and maintenance Safety/process safety ... 

During the last decade many industrial processes shifted towards using solid acid catalysts (6). In contrast to liquid acids that possess well-defined acid properties, solid acids contain a variety of acid sites (7). Sohd acids are easily separated from the biodiesel product they need less equipment maintenance and form no polluting by-products. Therefore, to solve the problems associated with liquid catalysts, we propose their replacement with solid acids and develop a sustainable esterification process based on catalytic reactive distillation (8). The alternative of using solid acid catalysts in a reactive distillation process reduces the energy consumption and manufacturing pollution (i.e., less separation steps, no waste/salt streams). 

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