Process equipment information related

Process Safety Information Physical, chemical, and toxicological information related to the chemicals, process, and equipment. It is used to document the configuration of a process, its characteristics, its limitations, and as data for process hazard analyses. 

Analysis of biological activity is sometimes difficult to correlate to corrosion rates. However, with detection and correlation of microbiological processes, especially those known to be related to corrosion (e.g., respiration rates, amount of acidity being produced) with process conditions, such information may also lead to improvements in the corrosion lifetime of the process equipment. 

There is also a certain amount of statistical information available on the failures of process system components. Arulanantham and Lees (1981) have studied pressure vessel and fired heater failures in process plants such as olefins plants. They define failure as a condition in which a crack, leak or other defect has developed in the equipment to the extent that repair or replacement is required, a definition which includes some of the potentially dangerous as well as all catastrophic failures. The failure rates of equipment are related to some extent to the safety of process items. If a piece of equipment has a long history of failures, it may cause safety problems in the future. Therefore it would be better to consider another equipment instead. It should be remembered that all reliability or failure information does not express safety directly, since all failures are not dangerous and not all accidents are due to failures of equipment. 

Other information that may be useful does not necessarily relate to the process equipment. For example, there are standard damage assessment references for correlating the damage to conventional construction to the corresponding overpressure wave experienced. However, to use these requires collection of data related to the structures that are damaged, not just the source of the pressure wave. 

Part 11 regarding validation of computer software and hardware. Any software used to operate process equipment, generate electronic records, track and transmit laboratory data, automate quality systems, operate critical utilities or software that is itself a medical device must be validated to ensure accuracy, reliability, consistency, and the ability to discern invalid or altered records. Where off-the-shelf software is used for any of the above cGMP activities, it must also be validated for its intended use. For additional information on compliance issues related to computer hardware and software validation refer to Chap. 7 of this book. 

The continuous development of the modem process industries has made it increasingly important to have information about the properties of materials, including many new chemical substances whose physical properties have never been measured experimentally. This is especially true of polymeric substances. The design of manufacturing and processing equipment requires considerable knowledge of the processed materials and related compounds. Also for the application and final use of these materials this knowledge is essential. 

All results from tests and evaluations at often many different locations and with various equipment, sometimes also including information from in-line testing and from pilot plant operations, are collected, compared with related know-how and experience, if available, and used for the engineering of the new plant and the selection of process equipment. In spite of all the efforts that normally go into the determination of these data, it is prudent to include safety factors during the design stage, which will allow optimization of the system if and when it comes on stream. 

A chemical reactor is a vessel manufactured from metal, often stainless steel or high resistant alloys. A minimum wall thickness is required to resist to different toads, and mainly to internal pressure. Accurate mechanical calculation of process equipment is a matter of mechanical engineering, and out of the scope of this book. Here we present only simple relations that permit the evaluation of weight and cost of vessels in a preliminary economic analysis. More information about mechanical design can be found in Coulson Richardson (1993). 

To maximize control in setting tolerances there is usually a minimum and a maximum limit on thickness, based on the process to be used. Available from the literature and material suppliers is extensive information on tolerances based on plastic related to fabricating process. Examples are provided in Tables 6.3 to 6.5. Each specific plastic has its own range that depends on its chemical structure and melt-processing characteristics. Outside these ranges, melts are usually uncontrollable. Any dimensions and tolerances are theoretically possible, but they could result in requiring special processing equipment, which usually becomes expensive. There are of course products that require and use special equipment. 

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