Technical Basis for Proposed Revisions to Asme Section Iii Code Case N-891 on Maximum Allowable Indentation Depths in Hdpe Pipe to Extend Applicability to Pent Ratings Up to 10,000 Hours

2021 ◽  
Author(s):  
Douglas Scarth ◽  
Prabhat Krishnaswamy ◽  
Phil Rush ◽  
Douglas Munson
Keyword(s):  
Hdpe Pipe ◽  
Technical Basis

Technical Basis for Proposed Revisions to ASME Section III Code Case N-891 on Maximum Allowable Indentation Depths in HDPE Pipe to Extend Applicability to PENT Ratings Up to 10,000 Hours

2020 ◽  
Author(s):  
Douglas Scarth ◽  
Prabhat Krishnaswamy ◽  
Phillip Rush ◽  
Douglas Munson
Keyword(s):  
High Density Polyethylene ◽  
Large Diameter ◽  
Surface Conditions ◽  
Test Conditions ◽  
Hdpe Pipe ◽  
Piping Systems ◽  
Current Maximum ◽  
Higher Temperature ◽  
Technical Basis ◽  
Hdpe Pipes

Abstract Mandatory Appendix XXVI of Section III of the ASME B&PV Code contains rules for the construction of Class 3 pressure piping systems comprised of PE4710 High Density Polyethylene (HDPE) with a minimum Pennsylvania Notched Test (PENT) rating of 2,000 hours. Appendix XXVI contains acceptance standards for the maximum allowable depths of gouges, cuts or other surface conditions that are characterized as indentations. The acceptance standards are very conservative, in particular for large diameter HDPE pipes. Less restrictive maximum allowable indentation depths for PE4710 HDPE pipes with a minimum PENT rating of 2,000 hours were previously developed based on analyses of tests on HDPE pipes containing scratches. These less restrictive maximum allowable indentation depths were published in the ASME Section III Code Case N-891 as an alternative to the acceptance standards in Appendix XXVI. The PENT rating of PE4710 HDPE material can significantly exceed 2,000 hours, and the current maximum allowable indentation depths in Code Case N-891 are overly-restrictive for the higher PENT ratings. Maximum allowable indentation depths for PENT ratings up to 10,000 hours have been developed, and are proposed to be implemented into a revision of Code Case N-891 and Appendix XXVI. The technical basis for the maximum allowable indentation depths for these higher PENT ratings is provided in this paper. The proposed revisions to Code Case N-891 include a provision to permit use of results from accelerated PENT testing at a higher temperature and stress level than standard PENT test conditions. The technical basis for the use of results from accelerated PENT testing is also provided in this paper.

Activization of Children’s Reading Interests in German Libraries

2009 ◽  
pp. 90-94
Author(s):  
Larisa E. Kresova
Keyword(s):  
Information Technologies ◽  
Reading Interests ◽  
New Information ◽  
American Memory ◽  
Children's Reading ◽  
Technical Basis ◽  
Children’S Reading

The activities of the American Memory Library, aimed at on activization of children’ reading interests in Germany are considered. The history, the collection composition, the material and technical basis and the organization of library space, as well as the usage of new information technologies in children's libraries of Germany are illuminated.

Design and Operational Analyses of Activated Sludge Processes Using Respirometrically Calibrated Models

1992 ◽  
Vol 26 (3-4) ◽  
pp. 753-762 ◽  
Author(s):  
A. F. Rozich
Keyword(s):  
Activated Sludge ◽  
Model Calibration ◽  
Process Model ◽  
Process Analysis ◽  
Case Histories ◽  
Model Case ◽  
Operational Strategies ◽  
Analysis Methodology ◽  
Technical Basis ◽  
Activated Sludge Processes

The purpose of this paper is to present the background and examples of methodology which enable environmental engineers and scientists to analyze activated sludge processes much more effectively than is otherwise possible with conventional approaches. Good process analyses are key for devising optimal design and operational strategies. The key features to the technique presented herein are the field-proven predictability of the model and the methodology for collecting data needed for calibrating the process model. Case histories prove the predictability of the model that is associated with the process analysis approach. The advantage of the approach advocated herein is the use of respirometric techniques to calibrate the model. These methods enable the process analyst to collect the requisite data for model calibration in twenty-four hours or less. This feature enables one to use this process analysis methodology for both design and operational applications. The paper will present the technical basis for the process model and how respirometric methods are utilized to compute biokinetic constants in a manner which is consistent with kinetic theory. Case histories will be discussed that demonstrate the predictability of the modeling approach and demonstrate the utility of this tool for process analysis.

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