Effective Condition Assessment: Washington Suburban Sanitary Commission’s Industry Leading PCCP Management Program

2019 ◽  
Author(s):  
Karem Carpio ◽  
Arturo Acevedo ◽  
Jorge Rodriguez
Keyword(s):  
Condition Assessment ◽  
Management Program ◽  
Effective Condition

scholarly journals Photoluminescence Spectroscopy Measurements for Effective Condition Assessment of Transformer Insulating Oil

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 732
Author(s):  
Abdelrahman M. Alshehawy ◽  
Diaa-Eldin A. Mansour ◽  
Mohsen Ghali ◽  
Matti Lehtonen ◽  
Mohamed M. F. Darwish
Keyword(s):  
Electronic States ◽  
Dissipation Factor ◽  
Condition Assessment ◽  
Transformer Oil ◽  
Term Operation ◽  
Pl Spectra ◽  
Insulating Oil ◽  
Vis Spectroscopy ◽  
Effective Condition ◽  
Dielectric Dissipation Factor

Condition assessment of insulating oil is crucial for the reliable long-term operation of power equipment, especially power transformers. Under thermal aging, critical degradation in oil properties, including chemical, physical, and dielectric properties, occurs due to the generation of aging byproducts. Ultraviolet-visible (UV-Vis) spectroscopy was recently proposed for the condition assessment of mineral oil. However, this absorption technique may involve all electronic states of the investigated material which typically yield a broad spectrum, and thus cannot precisely reflect the electronic structure of aged oil samples. It also cannot be implemented as an online sensor of oil degradation. In this paper, photoluminescence (PL) spectroscopy is introduced, for the first time, for effective condition assessment of insulating oil. The PL technique involves emission processes that only occur between a narrow band of electronic states that are occupied by thermalized electrons and consequently yields a spectrum that is much narrower than that of the absorption spectrum. Aged oil samples with different aging extents were prepared in the laboratory using accelerated aging tests at 120 °C, under which 1 day of laboratory aging is equivalent to approximately 1 year of aging in the field. These aged samples were then tested using PL spectroscopy with a wavelength ranging from 150 nm to 1500 nm. Two main parameters were evaluated for quantitative analysis of PL spectra: The full width at half-maximum and the enclosed area under the PL spectra. These parameters were correlated to the aging extent. In conjunction with PL spectroscopy, the aged oil samples were tested for the dielectric dissipation factor as an indication of the number of aging byproducts. Interestingly, we find a correlation between the PL spectra and the dielectric dissipation factor. The results of PL spectroscopy were compared to those of UV-Vis spectroscopy for the same samples and the parameters extracted from PL spectra were compared to the aging b-products extracted from UV-Vis spectra. Finally, the corresponding physical mechanisms were discussed considering the obtained results and the spectral shift for each spectrum. It was proved that PL spectroscopy is a promising technique for the condition assessment of insulating oil when compared to conventional transformer oil assessment measuring techniques and even to other optical absorption techniques.

Nuclear Plant Feedwater Heater Life Cycle Optimization Through Comprehensive Condition Assessment Program

2007 ◽  
Author(s):  
Daniel S. Thomas ◽  
Michael T. Coakley ◽  
Michael C. Catapano ◽  
Eric B. Svensson
Keyword(s):  
Life Cycle ◽  
Case History ◽  
Heating System ◽  
Life Cycle Management ◽  
Condition Assessment ◽  
Management Program ◽  
Complete Analysis ◽  
Cause Analysis ◽  
Life Cycle Optimization ◽  
Tube Plugging

Many papers published over the last 25 years have strongly emphasized the need for an ongoing program of condition assessment through inspection and testing with subsequent failure cause analysis of feedwater heaters. Plants must be run more competitively; therefore, Utilities must try to decrease operation and maintenance costs, while optimizing overall plant efficiency. One recognized area that needs to be addressed in accomplishing this goal is the heat cycle. This paper specifically deals with the feedwater heating system. Utility engineers must monitor feedwater heater performance in order to recognize degradation, identify and mitigate failure mechanisms, and prevent in-service failures while optimizing availability. Periodic tube plugging without complete analysis of the degraded/failed areas resolves the immediate need for return to service; however, heater life will not be optimized. This paper is a direct follow-up to a previously published ASME paper that detailed the establishment of a comprehensive life cycle management program for feedwater heaters implemented at Peach Bottom Atomic Power Station (PBAPS). This particular paper reports the eventual results and benefits achieved through the continuance and perseverance of this program. This successful condition assessment case history included the following inspection, testing, and maintenance activities to ascertain reliable data in support of root cause analysis: • Removal of previously installed plugs. • Videoprobe inspection of failed areas. • Videoprobe inspections of the steam space. • Extraction of tube samples for further analysis. • Eddy current testing of selected tubes. • Evaluation of the condition of “insurance” plugged tubes for return to service. • Hydrostatic testing of selected tubes. • Repair plans based on the results of the above program. • Reviewing operating data to assess case history. • Monitor and continue the program over future planned unit outages. This paper concludes that no single method of inspection or testing should solely be relied upon in assessing actual conditions. It is a combination of evaluating all gathered data that affords the best chance in arresting problems and optimizing feedwater heater life. Problem heaters should be continuously monitored over time until the facts ultimately help to justify replacement.

Asset Integrity Management of High Pressure Piping Systems Subject to Creep

2013 ◽  
Author(s):  
Marvin J. Cohn
Keyword(s):  
High Pressure ◽  
Creep Damage ◽  
Condition Assessment ◽  
Management Program ◽  
Piping System ◽  
Original Design ◽  
Operation And Maintenance ◽  
Piping Systems ◽  
Integrity Management ◽  
Construction Operation

Safety and reliability are the preeminent concerns in the design, operation, and maintenance of power piping. Recent additions to the ASME B31.1 Power Piping Code (Code) have addressed condition assessment of covered piping systems (CPS). Mandatory requirements for the condition assessment of CPS are discussed in Chapter VII of the Code and nonmandatory guidelines are discussed in Appendix V of the Code. These documents discuss design, fabrication, construction, operation, and maintenance issues, and do not provide detailed guidance in the evaluation of high pressure piping systems subject to creep. An asset integrity management (AIM) program should integrate and consider all attributes that influence the intended function of the original design. In addition to the evaluation of specified design, fabrication, construction, operation, and maintenance issues, an asset integrity management program should also consider and evaluate significant time-dependent anomalies, such as flexible operation modes, malfunctioning supports, and creep redistributed stresses. An AIM program includes the identification of governing drivers that accelerate piping system damage and then develops countermeasures to mitigate or reduce the driving mechanisms. This paper discusses the large range of piping system stresses and the sensitivity of stress increase to 50% creep life reduction, indicating the need for a robust stress ranking methodology. The process results in an accurate selection of the most critical creep damage weldments for nondestructive examinations.

Electron investigations of rhabdovirus-like particles in mexican bean beetles and crickets

1978 ◽  
Vol 36 (2) ◽  
pp. 378-379
Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty
Keyword(s):  
Biological Control ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Developmental Stages ◽  
Management Program ◽  
Acheta Domesticus ◽  
Epilachna Varivestis ◽  
House Cricket ◽  
Similar Morphology ◽  
Bean Beetle

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).

The Successful Stuttering Management Program: A Preliminary Report on Outcomes

2010 ◽  
Vol 20 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Jim Tsiamtsiouris ◽  
Kim Krieger
Keyword(s):  
Preliminary Report ◽  
Speech Rate ◽  
Management Program ◽  
Intensive Program ◽  
Adults Who Stutter

Abstract The purpose of this study was to test the hypothesis that adults who stutter will exhibit significant improvements after attending a residential, 3-week intensive program that focuses on avoidance reduction and stuttering modification therapy. Preliminary analyses focused on four measures: (a) SSI-3, (b) speech rate, (c) S-24 Scale, and (d) OASES. Results indicated significant improvements on all of the measures.

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