Components failures due

Possible large pipe and pipe component failures due to corrosion. 3 b ... 

The types of corrosion (i.e., the morphology of attack and the oxidation process) that can be encountered in organic liquids are the same as those observed in aqueous solutions. The solution chemistry and solution electrochemistry may be different, but the types of fundamental corrosion processes that occur remain the same. An excellent review of examples of corrosion in various organic solutions can be found in the work of Heitz [2]. In addition to a review of the fundamental principles involved, Heitz critically evaluates the literature published before 1973 and describes a number of industrial case histories of component failures due to... 

Stress corrosion is the failure of a metal resulting from the conjoint action of stress and chemical attack. It is a phenomenon associated with a combination of static tensile stress, environment and in some systems, a metallurgical condition which leads to component failure due to the initiation and propagation of a high aspect ratio crack. It is characterized by fine cracks which lead to failure of components are potentially the structure concerned. Stress corrosion cracking is abbreviated as see. The failures are more often sudden and unpredictable which may occur after as little as few months or years of previously satisfactory service. 

Prevention or at least minimization of fuel and/or oxidant leakage or intermixing of the fuel and oxidant is the most important attribute of an operating fuel cell. An intermixing of fuel and oxidant not only reduces efficiency but can also lead to premature component failure due to excessive local heating. The carbonate fuel cell has successfully adapted a simple wet seal concept. Liquid electrolyte held up in the micro-pores of the matrix and on the metal surface where the metal to matrix interface seal is involved, provide adequate barrier to gas leakage. 

Although checklists are a useful way of transferring information about human-machine interaction to designers and engineers, they are not a standalone tool and they cannot provide a substitute for a systematic design process. The main concern with checklists is that they do not offer any guidance about the relative importance of various items that do not comply with the recommendations, and the likely consequences of a failure due to a noncompliance. To overcome such problems, checklists should be used in combination with other methods of task analysis or error analysis that can identify the complexities of a task, the relationships among various job components, and the required skills to perform the task. 

EGSG Idaho s Idaho National Engineering Laboratory reviewed Licensee Event Reports (LERs), both qualitatively and quantitatively, to extract reliability information in support of the USNRC s effort to gather and analyze component failure data for U.S. commercial nuclear power plants. LERs describing failures or command faults (failure due to lack of needed input) for selected components have been analyzed in this program. Separate reports have been issued for batteries and battery chargers, control rods and drive mechanisms, diesel generators, ISC, Inverters, primary containment penetrations, protective relays and circuit breakers, pumps, and valves. 

Plant reliability problems are associated with excessive downtimes due to component failure or scheduled maintenance requirement. Development needs include ... 

Upon start-ups following emergency shut-ins, due to system component failure and recovery, such as compressor failure, without the opportunity to take inhibition steps. 

Figure 7.6 Semi-quantitative analysis of an organic two-component coating on a metal surface. The classifier grades the results into within specification (light grey), warning (white), mixing ratio/coverage outside specification (dark grey) and surface defects on the metal carrier (black). A significant isolated problem, B localised constant problem, C acceptable localised random flaws, E start of massive failure, F localised application of primarily one component only due to spray nozzle obstruction.

A number of important biochemical reactions occur intramitochondrially and some of these are described below. One major drawback to the study of energy metabolism in cestodes is the failure, due to technical difficulties, to produce isolated mitochondrial preparations of the purity which can be obtained from mammalian tissues. Generally, mitochondrial fractions of cestode origin are contaminated with other cellular components such as glycogen, endoplasmic reticulum and various membranes, and some of the data obtained with such mitochondria should, therefore, be treated with caution. 

It is a well-known fact that failure of an aircraft component can have catastrophic consequences such as loss of precious life and aircraft. It is obvious from Table 7.3 that failures due to fatigue are predominant in aircraft components. When the component is no longer able to withstand the imposed stress, failure will occur. Thus failures are associated with stress concentrations which can occur due to ... 

Because there are no drive components in the process area, the risk of batch failures due to contamination from gear lubricants is eliminated. However, the bottom joint requires especially careful design, maintenance, and sealing. The disassembly of the unit is simphfied, as all work on removing the screw can be done without vessel entry. For disassembly, the screw is simply secured from the top, and the drive components are removed from the bottom of the dryer. 

There is a direct relationship between water contamination and component usable life. Table 16.2 shows the loss of bearing usable life as a function of water concentration [14]. Water usually enters an oil system as a consequence of condensation from environmental exposure, coolant leak due to a component failure or free water ingress during equipment cleaning. 

Minimum loss of plant production, due to component failure, or scheduled maintenance, is made possible by use of dual, high-reliability, long-lived pumps as noted above, automatic shutdown and alarm on acid failure or pH outside set limits, and a three-line design of the six stacks. Upon failure or scheduled shutdown of any stack, only one other stack need be shut down and two-thirds plant capacity can be maintained. 

---