Cleanliness requirement

The manuals and other literature which specify how the tasks need to be performed The consumable materials and spares required The environment to be maintained if anything other than ambient The handling and cleanliness requirements The precautions to be observed to protect health and safety The checks, inspections, tests, and adjustments to be made A model servicing process is illustrated in Figure 19.2. 

The inside of a hydraulic system can only be kept as clean as the fluid added to it. Initial fluid cleanliness can be achieved by observing stringent cleanliness requirements (discussed later in this chapter) or by filtering all fluid added to the system. 

The standard of cleanliness which must be achieved has been stated to be that which will allow the subsequent process to be carried out satisfactorily . As an example, the degree of cleanliness required to satisfactorily zinc plate from an acid solution is somewhat higher than that required prior to zinc plate from a high-cyanide alkali zinc solution. This should never be taken as a licence to skimp on surface preparation. However, the arguments over surface-tolerant paint coatings abound and will probably continue. It is to a very large extent true that problems of early failure in metal finishing are traceable to incorrect or insufficient surface preparation. 

The above discussion has been based on conventional free-radical catalysis. There has been substantial research on long-lived free radicals that can give a living polymer without the severe cleanliness requirements of anionic polymerizations. Unfortunately, it has not yet had commercial success. 

A typical sample would have a surface area of the order 10 x 20 mm. The preparation of the surface for examination is the subject of an ASTM standard (ASTM E1078-97), and the objective is to ensure that the surface to be analysed has not been contaminated or altered prior to analysis. The techniques of surface analysis are sensitive to surface layers only a few atoms thick, so the degree of cleanliness required will be much greater than for other forms of analysis. Nothing must be allowed to touch the surface to be analysed. 

Any portion of the pressure lubrication systems furnished shall meet the cleanliness requirements of API Standard 614. 

For pressure-lubricated bearings, test stand oil and oil system components downstream of the filters shall meet the cleanliness requirements specified in ISO 10438-3. 

Local Control Under some circumstances, cleanliness requirements can be achieved through the use of localized controls such as clean tents, glove boxes, minienvironments, or isolators. These provide unidirectional filtered airflow within... 

Level of cleanliness required Temperature, pressure, separator efficiency, cycle time... 

For pharmaceutical applications small to medium sized, versatile, and often modular equipment is desired that must meet extreme cleanliness requirements (below). 

Validation and cleanliness requirements considerably burden the designs of all equipment for the pharmaceutical industry. To avoid cross-contamination it is necessary to include on modern machines CIP or at least WIP features. It is easily understandable that such techniques are difficult, to say the least, when considering the com-... 

Degree of cleanliness required as a result of the cleaning operation. 

Premises shall preferably be laid out corresponding to the sequence of the operations and to the air cleanliness required. The operations undertaken in the same and nearby areas shall not interfere with one another. Premises shall be protected against the entrance and harbour or vermin, birds, pests and pets. 

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