Deterioration repair

One of the most effective safety practices, as well as one highly conducive to productivity, is a definite scheduled program of preventive maintenance. Each item of equipment should be periodically removed from service, carefully inspected and calibrated, any faults or indications of deterioration repaired, and tagged with the date of review and the name of the maintenance person, if more than one technician could have been responsible. A permanent file or maintenance log on each major item of equipment is useful for identifying trends or weak components. 

Proc. 2nd International Conference on the deterioration and repair of reinforced concrete in the Arabian Gulf, Bahrain 1987. 

The aforementioned reviews and assessments were assimilated to characterize the effect of dielectric, rotational, and mechanical hazards on motor performance and operational readiness. Functional indicators were identified that can be monitored to assess motor component deterioration caused by aging or other accidental stressors. The study also includes a preliminary discussion of current standards and guides, maintenance programs, and research activities pertaining to nuclear power plant safety-related electric motors. Included are motor manufacturer recommendations, responses from repair facilities to a questionnaire, in-service inspection data, expert knowledge, USNRC-IE audit reports, and standards and guides published by the Institute of Electrical and Electronics Engineers (IEEE). 

The need for building repair arises from the inevitable process of ageing, and such deterioration is brought to light by systematic maintenance. There is also repair work necessitated by damage from observable causes such as physical impact (discussed elsewhere in this chapter). 

While preventive maintenance is concerned with regularly testing, and reconditioning equipment to prevent failures in service and premature deterioration, it follows that predictive maintenance procedures are concerned with the ability to predict when the equipment will fail and then developing schedules to implement timely repairs. Predictive maintenance does not imply that with the use of these techniques, failure modes in equipment can be prevented rather, it suggests that the occurrence of failure can be predicted and thus planned for. An appropriate example would be the inspection and change of a major compressor face-type oil seal where random heat checking (FM) has been observed over the years. 

Tvarusku, A. and Bennett, J. E., Proc. 2nd International Conference on Deterioration and Repair of Reinforced Concrete in Arabian Gulf, Bahrain, pp. 139-154 (1987)... 

Equipment can reasonably be expected to perform to its full capability when new but may deteriorate rapidly in use unless properly maintained and calibrated. Maintenance of equipment can be either preventive or curative. Some simple maintenance will be possible by the user however, in many cases it will be the responsibility of the manufacturer, supplier or a recognized agent. Use of this professional maintenance may be a condition of the warranty, and do-it-yourself repairs may invalidate the warranty. 

Regenerator cyclones have a typical life of 15-30 years depending upon erosion and mechanical fatigue. The base metal of the cyclones will deteriorate with time leading to graphitization. Once this happens, the metal cannot be welded upon and hence cannot be repaired during a normal unit TAR. This phenomenon is dependent upon time and temperature. COP is used to minimize the temperature to extend the cyclone life. 

Continual monitoring of equipment and plant is standard practice in chemical process plants. Equipment deteriorates and operating conditions may change. Repairs sometimes are made with improvements whose ultimate effects on the operation may not be taken into account. During start-up and shut-down, stream compositions and operating conditions are much different from those under normal operation, and their possible effect on safety must be taken into account. Sample checklists of safety questions for these periods are in Table 1.7. 

Since BkPdr deteriorates with the absorption of moisture and the containers in which it is stored are subject to rust, a thorough inspection of these articles must be made at least once a year. For this, one or several containers from each lot will be opened at the time, of annual inspection and if there is any doubt about serviceability of the pdr, it must be removed to the lab for physical and chemical testing. At the same time, the containers must be inspected for holes, weak spots, etc. Damaged containers should not be repaired but removed and the contents transferred to new containers. All of these operations may be called surveillance... 

The term "unusable component" that has replaced the term "unserviceable component", includes items that are in such a condition as to render them unfit for their intended purpose or for any other purpose. The unusable components may include materials or items of faulty manufacture (those that failed to pass inspection), deteriorated materials (those becoming ineffective or dangerous to handle), damaged items beyond repair (that can take place during manuf, shipping or storage), obsolescent materials (outdated, that have been replaced by newer, more effective items), captured materials and duds, which are items that have been properly initiated and failed to function, but are dangerous because they can explode any time later (Ref 9)... 

Answer 11.6 The Migennes well has already been discussed in the text. It is reported to be a confined well, but the tritium-14C combination indicates two water types are pumped in this well as a mixture. This nature is distinct from the comparison of the repeated measurements (10/67 and 7/69). In the last sample the percentage of recent water was greater than in the first sample. Corrosion and rupturing of the well casing may have deteriorated the well, so it pumps an increasing amount of shallow recent water. However, such a well may cause a short circuit between the two aquifers due to different hydraulic pressures, water from one aquifer may flow uncontrolled into the other aquifer. Repair of the well may be necessary. 

MCDONALD, M. B., Seed deterioration physiology, repair and assessment., Seed Sci. Technol., 1999,27, 177-237. 

The techniques used by the Central Library were relatively sophisticated for the time local librarians were given short indoctrination courses in those techniques and learned how to make simple repairs on books. However, in the majority of Spain s libraries, bookbinders, if they were available, doubled as restorers in archives, people did paste-and-paper repairs in addition to regular duties. No one, not even at the Central Library, was available to confront the broader problems of deterioration facing the custodians of the nation s records on paper and parchment. 

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