Field troubleshooting process 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. 

Sometimes I work with process equipment as a field troubleshooter. Sometimes I specify equipment as a process design engineer. And often, I teach shift operators and plant engineers how equipment works. Whatever I m doing, 1 have in mind my childhood experiences in south Brooklyn. 1 focus on the analogy between the complex problem of today and the simple experiences of everyday life. 

Norman P. Lieberman is a chemical engineer with 50 years of experience in process plant operation, design, and field troubleshooting. An independent consultant, he troubleshoots oil refinery and chemical plant process problems and prepares revamp designs. Mr. Lieberman teaches 20 seminars a year on "Troubleshooting Process Plant Operations" and has written eight books on plant process operations and problems. 

Testing equipment and procedures. Most compounders employ a variety of testing tools to control and monitor their manufacturing processes, as weU as their R D programs, and for troubleshooting problems encountered in the field. A list of such equipment follows. 

Product failures in the field sometimes occur at very low levels, on the order of defects per million. The determination of the failure mechanism in these cases is often very difficult because more than one factor leads to the failure. In many cases, two distinct situations have to occur simultaneously for the failure to occur. And in some cases, three or more factors need to coincide. In this paper, we describe the failure analysis of a solution container which was found to have panel leaks. In a future paper, we hope to outline how the failure mechanism was used to troubleshoot the product manufacturing process and solve the problem in the field. 

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