The selection of equipment

In general, equipment is developed, rather than designed, for an application. That is to say, designs for a new device off the drawing board are seldom suitable for incorporation within a plant without 

The responsibility of the vendor is to design and manufacture equipment which complies with the specification and is fit for the purpose and environment, as described, and as known by the vendor in terms of his previous experience. 

Most standard commercial conditions are based on similar precepts to the above. Some practitioners take the role definition a step further by avoiding use of the word approval altogether, and using review , so as to emphasize that there is no responsibility shift. Others argue that this is going too far - that the implied responsibilities can be made quite clear by the conditions of purchase, and that the right of approval is essential. 

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The selection of equipment for the treatment of solid particle emissions to the atmosphere depends on a number of factors ... 

The thermal duty here is the opposite of solidification operations. The indirect heat-transfer equipment suitable for one operation is not suitable for the other because of the material-handling rather than the thermal aspects. Whether the temperature of transformation is a definite or a ranging one is of little importance in the selection of equipment for fusion. The burden is much agitated, but the beds are deep. 

A guide to the. selection of equipment may be based on ieed.size and hardness (see subsec tion Grindability ) as shown in Table 20-7. It should be emphasized that Table 20-7 is merely a guide and that exceptions can be found in practice. 

These matters are organized into three major divisions the types of equipment, the criteria employed in the selection of equipment, and the sizing and design of the equipment. 

The selection of equipment to meet the above needs depends on many factors options include these ... 

There are two categories of equipment which determine the selection of equipment general-purpose and special-to-type equipment. It should not be necessary to specify all the general-purpose equipment needed to perform basic measurements, which would be expected to be known by appropriately trained personnel. You should not need to tell an inspector or tester which micrometer, vernier caliper, voltmeter, or oscilloscope to use. These are the tools of the trade and they should select the tool which is capable of measuring the particular parameters with the accuracy and precision required. However, you will need to tell them which device to use if the measurement requires unusual equipment or the environmental conditions prevailing require that only equipment be selected that will operate in such an environment. In such cases the particular devices to be used should be specified in the test or inspection procedures. In order to demonstrate that you selected the appropriate device at some later date, you should consider recording the actual device used in the record of results. With mechanical devices this is not normally necessary because wear should be detected well in advance of there being a problem by periodic calibration. 

In areas where electrical equipment is exposed to contaminants, the selection of equipment whose contacts are oil-immersed or hermetically sealed can increase reliability and equipment life. Similarly, providing environmentally-controlled equipment rooms can greatly increase equipment life at locations where contaminants are prevalent. In offshore and other areas exposed to salt, type 316 stainless steel is often preferred over types 303 and 304, which will pit with time. Likewise, in similar locations, equipment fabricated from galvanized steel will corrode much more rapidly than equipment hot-dip galvanized after fabrication. 

Much equipment for the separation of liquids and finely divided solids was invented independently in a number of industries and is of diverse character. These developments have occurred without benefit of any but the most general theoretical considerations. Even at present, the selection of equipment for specific solid-liquid separation applications is largely a process of scale-up based on direct experimentation with the process material. 

There are several other factors that are important when it comes to the selection of equipment in a measurement process. These parameters are items 7 to 13 in Table 1.2. They may be more relevant in sample preparation than in analysis. As mentioned before, very often the bottleneck is the sample preparation rather than the analysis. The former tends to be slower consequently, both measurement speed and sample throughput are determined by the discrete steps within the sample preparation. Modern analytical instruments tend to have a high degree of automation in terms of autoinjectors, autosamplers, and automated control/data acquisition. On the other hand, many sample preparation methods continue to be labor-intensive, requiring manual intervention. This prolongs analysis time and introduces random/systematic errors. 

A cost equation may be written to include all the costs, which are expressed in terms of the capacity of the flow-scheme components. The selection of equipment sizes that minimize capital investment is (1) complicated by interrelations between pieces of equipment, (2) limited by the discontinuity in size of standard equipment, (3) fixed by the availability of idle or used equipment, and (4) restricted by the higher cost of custom-made equipment. Writing one equation for a complete plant is a complex task. It is more likely that it may be done for small sections of the plant which can be operated as interrelated trains. 

Detailed equipment and functional specifications are produced to aid in the selection of equipment and control strategy. 

The availability, size, and surfaces or composition of the required equipment should be specifically identified so that the scale-up effort may be representative of a production run. A preliminary compatibility screen of contact surfaces should be completed before the selection of scale-up equipment. The location of the equipment in reference to other requirements, such as services or the packaging area, may be a factor in the selection of equipment. A cleaning-validation study should be conducted to ensure that no residues of active ingredient or cleaning agent remain after cleaning and that the equipment is suitable for production use again. Alternative equipment may be considered and used however, experience will dictate its suitability. 

In one area at least, in the provision of equipment, solutions are possible. Hakansson has pointed out, if the selection of equipment for school science is based upon principles rather than upon obtaining accurate results, very simple and quite in expensive equipment can be used. 

Proper selection of equipment for degumming of silk is essential to prevent chafed surface, chafe marks, uneven degumming and chemical damage. However, the selection of equipment depends on the type of the article to be processed. 

Published performance data on various pieces of equipment and different materials is still relatively scarce. More of this work would help in the selection of equipment and in the understanding of the effects of equipment and particle variables. Examples which clearly illustrate sound methods of measurement, calculation of product uniformity, and control of product quality and photographs of mixing and particle movements, would also be helpful in developing this area. 

It is important to involve Production during the product design stage in the selection of equipment and the process. The eventual technology transfer is likely to be smoother if the same type of equipment employed by R D is also available in Production on a larger scale. If a completely novel approach to manufacture is being considered, it is important that Production is made aware of this and can plan ahead to deal with the new process. This might involve the purchase of new equipment which will have to be validated. 

Selection of Size-reduction Equipment. The following factors are determinants in the selection of equipment for size reduction of materials ... 

Some of these documents have become obsolete or little used, e.g. BS229, BS1259, Electrical Installations in Flammable Atmospheres (from ICI) whilst others have been up-dated several times. New standards have also been introduced. A similar situation exists with the international standards pertaining to the selection of equipment for hazardous areas, many more references could be quoted. 

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