Consideration on the Representations of Sealing Behavior of Gaskets: Effects of the Internal Pressure and the Gasket Width

2003 ◽  
Author(s):  
Takashi Kobayashi ◽  
Takahito Nishida ◽  
Yuki Yamanaka
Keyword(s):  
North America ◽  
Internal Pressure ◽  
Evaluation Method ◽  
Environmental Concern ◽  
Evaluation Methods ◽  
Leak Rate ◽  
Piping System ◽  
Mathematical Form ◽  
The North ◽  
Recent Increase

With the recent increase of a safety and environmental concern, it is important to estimate the leak rate of gasketed flanged connections in piping system. In order to estimate the leak rate, the sealing behavior of a gasket must be known. Currently, evaluation methods of the sealing behavior are proposed in the North America and Europe independently. However, the effects of the internal pressure and the gasket width are not sufficiently considered in both the methods. We have already proposed an evaluation method of sealing behavior based on the gasket strain in a mathematical form, in which the internal pressure and the gasket width are considered. In this paper, the effects of the internal pressure and the gasket width on the leak rate are discussed by applying the evaluation method to ASME and JIS flanges. Comparing the estimated results with those of PVRC and CEN methods, problems are pointed out.

Method to Estimate the Bolt Loads to Satisfy Tightness Criteria for Gasketed Bolted Flanged Connections

2010 ◽  
Author(s):  
Takashi Kobayashi ◽  
Kiichi Masui ◽  
Kengou Nishiura ◽  
Hideshi Shibata
Keyword(s):  
North America ◽  
Environmental Concern ◽  
Test Method ◽  
The North ◽  
Recent Increase ◽  
Simplified Method ◽  
The Relationship

With the recent increase of a safety and environmental concern, the tightness of gasketed flanged connections becomes an important issue. In estimating the tightness of gasketed flanged connections, the sealing behavior of gaskets must be known. Currently, methods to test the sealing behaviors have been established in the North America, Europe and Japan. However, the relationships between the gasket data and the tightness of gasketed flanged connections have not been examined systematically. This paper consists of two parts: gasket data concerning sealing behavior and tightness of gasketed flanged connections. Firstly, several sheet gaskets were tested based on the test method JIS B 2490 in order to grasp tightness characteristics of gaskets. Secondly, tightness tests are carried out using blind flanges with the gaskets used in the gasket test. Both the results are compared and discussed to highlight the relationship between them. It is shown that the tightness of bolted flanged connections is largely affected by the sealing behavior of gaskets. Finally, based on the results, a simplified method to estimate the tightness of flanged connections is proposed and applied bolting load.

The Relationship Between Sealing Behavior of Gaskets and the Leak Tightness of Gasketed Bolted Flanged Connections

2009 ◽  
Author(s):  
Takashi Kobayashi ◽  
Kiichi Masui ◽  
Wong Teck Soon
Keyword(s):  
North America ◽  
Environmental Concern ◽  
Test Method ◽  
The North ◽  
Recent Increase ◽  
Simplified Method ◽  
Leak Tightness ◽  
The Relationship

With the recent increase of a safety and environmental concern, the tightness of gasketed flanged connections becomes an important issue. In estimating the tightness of gasketed flanged connections, the sealing behavior of gaskets must be known. Currently, methods to test the sealing behaviors have been established in the North America, Europe and Japan. However, the relationships between the gasket data and the tightness of gasketed flanged connections have not been examined systematically. This paper consists of two parts: gasket data concerning sealing behavior and tightness of gasketed flanged connections. Firstly, several sheet gaskets were tested based on the test method JIS B 2490 in order to grasp tightness of gaskets. Secondly, tightness tests were carried out using blind flanges with the tested gaskets by JIS B 2490. Both the results were compared and discussed to highlight the relationship between them. It is shown that the tightness of bolted flanged connections is largely affected by the sealing behavior of gaskets. Based on the results, a simplified method to estimate the tightness of flanged connections is proposed.

Simplified Sealing Test Procedure of Gaskets Based on Compressive Strain

2002 ◽  
Author(s):  
Takashi Kobayashi ◽  
Takahito Nishida ◽  
Yuki Yamanaka
Keyword(s):  
Environmental Concern ◽  
Compressive Strain ◽  
Test Procedure ◽  
Complex Loading ◽  
Testing Procedure ◽  
Leak Rate ◽  
Strain Diagram ◽  
Stress Strain ◽  
The North ◽  
Behavior Based

With the recent increase of safety and environmental concern, the estimation of leak rate of a gasketed flanged connection in piping systems is an important subject to be studied. In order to estimate the leak rate, the sealing behavior of a gasket must be known. Currently, evaluation methods of the sealing behavior are proposed in the North America and Europe independently. One of the problems is that the representations of the sealing behavior are rather complex in both the methods. Thus, gasket tests take a long time to perform and cost much. The authors have carried out investigations on the sealing behavior of compressed fiber sheet gaskets and have shown that the leak rate is uniquely determined by the compressive strain of gasket. This fact makes the test procedure much easier eliminating complex loading-unloading sequences. A simplified leak testing procedure, in which a simple one-way loading is employed, has proposed. Furthermore, an equation for the sealing behavior of gasket, in which the effect of dimensions of gaskets is taken into consideration, has proposed. In this study, investigations on the sealing behaviors are overviewed first. Then, it is shown that the conventional sealing behavior based on the gasket stress is easily obtained from the sealing behavior based on the gasket strain and the stress-strain diagram of gasket. Both the sealing behavior and the stress-strain diagram of gasket are expressed by equations in this method. Finally, it has also shown that the sealing behavior obtained by the simplified test can be fully converted to the ROTT (ROom Temperature Tightness Test) forms.

The Sealing Behavior of Large Diameter Flanged Connections and a Method to Determine Bolt Loads to Satisfy Tightness Criteria

2011 ◽  
Author(s):  
Takashi Kobayashi ◽  
Masahiro Kogasaka ◽  
Kengou Nishiura ◽  
Kazuaki Uchiyama
Keyword(s):  
Internal Pressure ◽  
Thrust Force ◽  
Environmental Concern ◽  
Large Diameter ◽  
Small Diameter ◽  
Test Results ◽  
Recent Increase ◽  
Sealing Performance ◽  
The Difference

With the recent increase of a safety and environmental concern, the tightness of gasketed flanged connections becomes an important issue. However, the estimation of bolt loads to satisfy the tightness of gasketed flanged connections has not yet been fully established, especially in the case of large diameter flanges. In this paper, the sealing behavior of a large diameter gasketed flanged connection, in which 16 inch blind flanges were used, was examined experimentally. The variations of bolt loads were also measured when the flanged connection was subjected to an internal pressure. In the experiments, two kinds of sheet gaskets were used. It was shown that the bolt loads of large diameter flanges were reduced significantly and a gross leak occurred due to a large thrust force caused by an internal pressure and that the gasket characteristics affect the sealing behavior significantly. The test results were compared with those of small diameter gasketed flanged connection to highlight the difference of the sealing performance.

Political orientation and moral foundations

2019 ◽  
Vol 118 (11) ◽  
pp. 365-371
Author(s):  
J Dorasamy ◽  
Mr Jirushlan Dorasamy
Keyword(s):  
South Africa ◽  
North America ◽  
American Studies ◽  
Political Orientation ◽  
The Political ◽  
Moral Foundations ◽  
Open Approach ◽  
Online Questionnaire ◽  
Moral Foundation ◽  
The North

Studies, especially in the North America, have shown a relationship between political orientation and moralfoundation. This study investigated whether moral judgements differ from the political orientation of participantsin South Africa moral judgment and the extent to which moral foundations are influenced by politicalorientation.Further, the study investigated the possibility of similar patterns with the North AmericanConservative-Liberal spectrum and the moral foundation. There were 300participants, 78 males and 222 females,who completed an online questionnaire relating to moral foundation and political orientation. The results partiallysupported the hypothesis relating to Liberal and Conservative orientation in South Africa. Further, this studypartially predicted the Liberal-Conservative orientation with patterns in the moral foundation, whilst showingsimilar findings to the North American studies. A growing rate of a neutral/moderate society is evidenced in SouthAfrica and abroad, thereby showing the emergence of a more open approach to both a political and generalstance.”””

scholarly journals Progress in Diagnosing Primary Ciliary Dyskinesia: The North American Perspective

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1278
Author(s):  
Michael Glenn O’Connor ◽  
Amjad Horani ◽  
Adam J. Shapiro
Keyword(s):  
Genetic Testing ◽  
North America ◽  
North American ◽  
Primary Ciliary Dyskinesia ◽  
Clinical Phenotype ◽  
The United States ◽  
Diagnostic Process ◽  
The North ◽  
Diagnostic Guideline ◽  
Ciliary Dyskinesia

Primary Ciliary Dyskinesia (PCD) is a rare, under-recognized disease that affects respiratory ciliary function, resulting in chronic oto-sino-pulmonary disease. The PCD clinical phenotype overlaps with other common respiratory conditions and no single diagnostic test detects all forms of PCD. In 2018, PCD experts collaborated with the American Thoracic Society (ATS) to create a clinical diagnostic guideline for patients across North America, specifically considering the local resources and limitations for PCD diagnosis in the United States and Canada. Nasal nitric oxide (nNO) testing is recommended for first-line testing in patients ≥5 years old with a compatible clinical phenotype; however, all low nNO values require confirmation with genetic testing or ciliary electron micrograph (EM) analysis. Furthermore, these guidelines recognize that not all North American patients have access to nNO testing and isolated genetic testing is appropriate in cases with strong clinical PCD phenotypes. For unresolved diagnostic cases, referral to a PCD Foundation accredited center is recommended. The purpose of this narrative review is to provide insight on the North American PCD diagnostic process, to enhance the understanding of and adherence to current guidelines, and to promote collaboration with diagnostic pathways used outside of North America.

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