Troubleshooting operating problems

The system that experienced the failure had been modified within the previous decade. Instrumentation and control changes made it difficult for field crews to diagnose and troubleshoot operating problems. Process safety information had not been properly documented and there was litde evidence that the changes had been formally evaluated. A few days before the incident, a tag was installed on a faulty letdown valve instructing that a bypass must not be used. No explanation was given for this instruction. 

V. Inouye, H. Kanai, et al., Guide for troubleshooting operator problems in the Hall 700 and 700A electrolytic conductivity detectors, J. Chromatogr. Sci., 22 262-263 (1984). 

Coating and Drying Defects Troubleshooting Operating Problems, 2" Edition, Wiley-Interscience, New York, 2006. 

Gutoff, E. and E. Cohen, Coating and Drying Defects - Troubleshooting Operating Problems, John Wil Sons,lac., 1995. 

Gutoff, E.B., Cohen, E.D., and Kheboian, G.I.,, Coating and Drying Defects Troubleshooting Operating Problems, Wiley Interscience, New York, 1995. 

Measurement Selection The identification of which measurements to make is an often overlooked aspect of plant-performance analysis. The end use of the data interpretation must be understood (i.e., the purpose for which the data, the parameters, or the resultant model will be used). For example, building a mathematical model of the process to explore other regions of operation is an end use. Another is to use the data to troubleshoot an operating problem. The level of data accuracy, the amount of data, and the sophistication of the interpretation depends upon the accuracy with which the result of the analysis needs to oe known. Daily measurements to a great extent and special plant measurements to a lesser extent are rarelv planned with the end use in mind. The result is typically too little data of too low accuracy or an inordinate amount with the resultant misuse in resources. 

The ability to quickly identify and eliminate costly operating problems ean frequently save thousands of dollars. Here are some helpful troubleshooting tips. 

Shortly after the valve to the sump was opened and the valve to the hopper was closed, the No. 4 reactor began experiencing erratic pressure problems. The system pressure troubles continued for about 15 minutes. As the supervisor and operator were troubleshooting the problem the relief valve on the reactor heat transfer chest opened with a loud report, signaling real troubles. The two employees started to head out of the unit. About 20 seconds later a large section of a 9 ft. (2.7 m) in diameter expansion joint burst. The initial explosion and the resulting thrust shifted the massive reactor. 

In order to perform this task the staff must first retrieve the requisition for the case and be able to confirm that the appropriate procedure was requested at the time of accession. When the identity of the patient (and/or case number) is confirmed, the next assessment required is to confirm that the number of tissue blocks submitted has produced the appropriate number of slides and stains. This task requires a well trained technician who is attentive to details and has a thorough understanding of the operations in the histology laboratory. If the case is incomplete the technician must troubleshoot the problem in order to locate the missing materials. 

The final component we need to consider is the instrumentation and control system (Figure 14-10). Good instrumentation is vital to ensure that an extrusion line is operating efficiently and to troubleshoot extrusion problems. Because we cannot see inside the extruder, nor would we leam much even if we could, instrumentation serves as a window onto the process. Monitoring an extrusion system has been compared to monitoring a patient in the hospital you always need to measure vital signs, like blood pressure and body temperature. Likewise, an extrusion line that is not properly monitored can... 

Guides for troubleshooting HPLC instrumentation provide analysts and laboratory technicians with a readily available, very useful aid for solving operational problems of equipment and techniques. In order that the chromatographer effectively solves an arising problem in HPLC, he/she should be aware of the role of operating parameters, as these are indicators of system performance. Step-by-step troubleshooting protocols for each system component should be followed to isolate the problem and its cause. 

Kister says that d/b plots are primarily used when there is a tight spec, on a nonkey component or a concern about the distribution of an intermediate key component. His book shows d/b curves for various feed stage locations on a plot of the mole ratio of a reference component in the distillate to the bottom product, versus the relative volatility of each component to this reference component. This plot is made on log-log paper. The optimum feed produced a curve closest to linear. The d/b plot is suggested as a troubleshooting tool in the subsection of the Troubleshooting section, Fractionation Operating Problems. ... 

Some theory is included to provide the necessary insight into the unit operation but is not emphasized. Rather, the emphasis is placed on the practical aspects of development, design and operation—how one goes about collecting design data, what are the scale-up parameters, how to select the right piece of equipment, where operating problems arise, and how to troubleshoot. 

The second type of process risk is to do with troubleshooting. In such situations, the facility suffers from ongoing operating problems that eat away at profits and take up the time of key personnel. The causes of the problem are often hard to identify. 

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