The decision tree and specific steps required to resolve these problems vary depending on the type of problem and its forcing functions or causes. Once secured, the scene must be fully documented. Catastrophes, such as the Bhopal chemical release, the Exxon Vuldez oil spill, New York's Love Canal, and dioxin-contaminated Times Beach in Missouri, have led several federal departments and agencies to enact protective regulations. The flow rate and pressure of the flushing liquid will vary, depending on the specific type of seal, but must be enough to assure complete, continuous flushing. The fishbone graph provides no clear sequence of events that leads to failure. Perhaps the most difficult part of the analysis is separating fact from fiction. Generally, specifications do not include enough detail to ensure that the correct part or machine is purchased.
Thomas Register of American Manufacturers. The guidelines for specific machine types, which are provided in Part Two, and the troubleshooting guides in Part Three should be used as part of this activity. In addition, many documents must be gathered and reviewed to extract the relevant information. Once all the identified factors have been graphically displayed, the investigator or investigating team can systematically evaluate each one. Library of Congress Cataloging-in-PublicationData Mobley, R. Each failure mode and resulting effect is assigned a criticality rating, based on the probability of occurrence, its severity, and its delecta- bility.
Ask a supervisor what to do with old or unused chemicals in your work area. It provides an objective basis for analyzing system design, justifying system changes, performing trade-off studies, analyzing common failure modes, and demonstrating compliance with safety and environment requirements. This section also should designate the person by name responsible for ensuring that the lessons learned are communicated, a completion date for the communication,and a list of the specific plant personnel who should receive the communications. This type of impeller generally is used for clean, solid-free liquids. The wear pattern or surface finish of parts may provide clues that will help the investigator resolve a problem. Because the shear pins had been removed and replaced with Grade5 bolts.
After the recommended corrective action has been implemented, a series of confirmation tests should be conducted to ensure reliable operation of the corrected application or machine. Most production areas maintain some historical data that track its performance and practices. Tahap ini mencakup wawancara beberapa personel, mengumpulkan bukti fisik, dan melakukan penelitian yang lain seperti menganalisis rangkaian kejadian yang dibutuhkan untuk memperjelas pemahaman dari masalah. This information is mandatory for all equipment-related problems, and it is extremely useful for other events as well. The effect of each failure mode then is traced up to the system level. Higher levels of input energy can result in catastrophic, near instantaneous failure of the machine or structure. Analysis generally is not performed on problems that are found to be random, nonre- curring events.
Procurement Specijications Procurement specifications normally are prepared for all capital equipment as part of the purchasing process. In most cases, the communication will not contain a complete description of the problem. It is different from a failure mode and effect analysis in that it is restricted to identifying system elements and events that lead to one particular undesired event. For a complete listing of the reportable chemical used in your plant, refer to the site Hazardous Materials Policy and Procedure Manual. These data should be reviewed to determine the actual production practices that are used to operate the machine or system being investigated.
Wear Particles Wear-particle analysis is a diagnostic technique that uses visual analysis aided by an electron microscope to evaluate the wear patterns of the metallic solids contained in a 36 Root Cause Failure Analysis Figure 3-6 Viwl profile of abnormal loading of a rolling-element bearing. Fatigue is another factor that directly affects training. Photographs, videotape, or diagrams of the incident scene. Each technique is appropriate for specific applications and provides a means of quantifying or proving that specific forcing functions contributed to the event or incident being investigated. A conversation with a process engineer identified the diaphragms used to seal the blow-down tubes as a potential problem source.
The publisher offers special discounts on bulk orders of this book. If the employee was on restricted duty, the investigator also should determine if the restriction had any bearing on the incident. If the recommended change is valid, the value of the benefits should far outweigh the costs. The person reporting the problem was convinced that chronic failure of the solenoid-actuated pilot valves controlling the blow-down of the baghouse, without a doubt, was the cause. In addition to the capacity gain, the increase in availability has the additional benefit of reducing the cost per unit of both production and maintenance.
This section should describe what intermediate or quick-fi actions were taken to permit resumption of production. The review should clearly define the allowable boundaries used for the system's design. If possible, the failed machine and its installed system should be isolated from service until a full investigation can be conducted. If there is any misalignment or eccentric shaft rotation, the probability of a mechanical seal failure is extremely high. Friction wastefully consumes energy and wear changes dimensions.
In some cases, restriction in the prior processes may be the root cause of the perceived problem. It is too easy to address the symptoms or perceptions without a full analysis. Therefore, the investigator should evaluate the functional requirements of the employee involved in the accident or safety violation to determine if repetition was a contributing factor in the incident. The actual parameters will vary depending on the machine or system. Fault-tree analysis is a detailed deduc- tive analysis that usually requires considerable information about the system. It should detail specific recommendations for long-term corrective actions.