Development of a Protocol to Determine the Minimum Operating Stress of Compressed Non-Asbestos Gaskets

2013 ◽  
Author(s):  
Ana C. Silva ◽  
Gabriele Rodrigues ◽  
Lucas Xavier
Keyword(s):  
New Method ◽  
Test Results ◽  
Flange Joint ◽  
Stress Determination ◽  
Complex Approach ◽  
Bolt Stress ◽  
Operating Stress ◽  
Bolted Flange ◽  
Minimum Operating

The ASME PCC-1-2010 Guidelines for Pressure Boundary Bolted Flange Joint Assembly [1] introduced a new method for an appropriate assembly bolt stress determination across bolted flange connections. The method introduced in APPENDIX O of the ASME PCC-1-2010 has recently received substantial attention by several gasket researchers. In this new method, calculation is based in a complex approach that considers the integrity of each joint component. However, almost no information is found about some essential parameters. Therefore, the intent of the present study is to introduce a protocol for the determination of one of these factors: the minimum gasket operating stress (Sgmin-o). This value is defined as “the gasket stress that should be maintained on the gasket during operation in order to assure the leakage does not occur”. This paper will show a detailed study for a protocol to determine the minimum gasket operating stress and actual test results for compressed non-asbestos gaskets. Furthermore, the device used in the research will be defined in detail afterwards.

Determination of ASME PCC-1-2010 Appendix-O Gasket Parameters

2014 ◽  
Author(s):  
André F. Garcia ◽  
Camila M. Dias ◽  
Sulivan T. Pereira
Keyword(s):  
Calculation Method ◽  
Material Composition ◽  
New Method ◽  
Flange Joint ◽  
Method Calculation ◽  
The Past ◽  
Load Calculation ◽  
Operating Stress ◽  
Bolted Flange

The bolt load calculation method introduced in Appendix-O of ASME PCC-1-2010 – Guidelines for Pressure Boundary Bolted Flange Joint Assembly [1] – has drawn attention from the gasket researching community in the past few years. In this new method, calculation is based on parameters that consider the integrity of each joint component. The parameters related to the gasket are the maximum permissible gasket stress, minimum gasket seating stress and the minimum gasket operating stress. In Appendix-O, those parameters are defined, but no information is provided on how to determine them. The intent of this paper is to determine the values of those parameters for gaskets in different material composition for different thicknesses, and to evaluate the influence of those variables on the parameters.

Determination of Deflection of the Vertical by the Astrogeodetic Difference Method

1982 ◽  
Vol 36 (2) ◽  
pp. 183-190
Author(s):  
W. F. Teskey
Keyword(s):  
Field Test ◽  
Difference Method ◽  
Systematic Errors ◽  
Cost Estimate ◽  
New Method ◽  
Test Results ◽  
Deflection Of The Vertical ◽  
Potential Applications

In certain survey applications the effect of deflection of the vertical cannot be ignored without producing large systematic errors. To avoid this problem some method of determining deflection, or change in deflection, must be used. A new method to determine change in deflection, the astrogeodetic difference method, is described. Field test results confirming the accuracy of the method are given. A cost estimate is made and potential applications are briefly discussed.

A Novel Approach to Evaluating Spiral-Wound Gaskets in Bolted Flange Joint Calculations

2006 ◽  
Author(s):  
Trevor G. Seipp ◽  
Christopher Reichert ◽  
Mathew Schaeffer
Keyword(s):  
Solid Metal ◽  
Flange Joint ◽  
New Approach ◽  
Novel Approach ◽  
Division 1 ◽  
Bolt Stress ◽  
Section Viii ◽  
Bolted Flange ◽  
Spiral Wound

In this paper, the authors introduce a compound gasket approach to performing calculations on bolted flange joints with spiral wound gaskets. The spiral windings and the solid-metal centering ring are treated independently. Using the calculation methodologies of ASME Section VIII, Division 1, Appendix 2 and EN-1591-1, the authors calculated the assembly bolt stress for multiple bolted flange joint sizes over a range of classes. The calculations assumed that the flange sealed on the solid-metal centering ring as well as on the spiral windings. This bolt stress required to achieve this seal was added to the bolt stress required to compress the spiral windings fully to the centering ring. The resulting total bolt stresses are similar to the practical bolt stresses recommended by ASME PCC-1. Thus, using this new approach to the spiral wound gasket provides a better understanding of bolt stresses required to achieve an adequate bolted flange joint.

Study on the gasket parameters and the calculation of MMC flange joint according to XP CEN\TS 1591-3

2016 ◽  
Vol 231 (6) ◽  
pp. 1174-1186
Author(s):  
Lanzhu Zhang ◽  
Jiachao Sun ◽  
Renliang Cai
Keyword(s):  
Nuclear Power ◽  
Service Condition ◽  
Test Methods ◽  
Metal Contact ◽  
Not Given ◽  
Test Results ◽  
Flange Joint ◽  
Stress Relaxation Test ◽  
Contact Type ◽  
Bolted Flange

Metal-to-metal contact type flange joints (bolted flange joint with metal-to-metal contact) have a constant gasket sealing stress during service, so it is extensively used for “zero leakage” design in petrochemical, chemical, or nuclear power industry. XP CEN\TS 1591-3 provides a calculation method for metal-to-metal contact flange joints but the gasket parameters needed in this calculation and their test methods are not given. To determine the gasket parameters of metal-to-metal contact type flange joints, the procedures of the compression–resilience test, the stress relaxation test, and the sealing test at different temperature were described here, and the main mechanical properties and sealing property of a metal-to-metal contact type gasket were obtained from these tests. The methods to determine the metal-to-metal contact gasket parameters were introduced. And then, the calculation for a DN80 PN5.0 metal-to-metal contact type flange joint was carried out with two methods, one was the method according to XP CEN\TS 1591-3, the other was finite element method. In these calculations, the assembly condition and service condition were considered. The results of the two methods coincided well. This showed the test methods and test results of metal-to-metal contact type gasket parameters suggested here were available. So, they could be applied for the calculation of metal-to-metal contact type flange joints.

scholarly journals Solving the Puzzle of Bolted Joints

2011 ◽  
Vol 133 (06) ◽  
pp. 48-52
Author(s):  
Edward Hayman ◽  
Clyde Neely
Keyword(s):  
Best Practices ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Flange Joint ◽  
Unit Load ◽  
Bolt Stress ◽  
Torque Values ◽  
Bolted Flange ◽  
Joint Integrity ◽  
Joint Assembly

This article discusses the various ways of solving the puzzle of bolted joint assembly. In 2001, The PCC-1-2000 Guidelines for Pressure Boundary Bolted Flange Joint Assembly presented with knowledge and practices specific to the assembly of bolted flange joints. The puzzle solution that came from this box was the most definitive to date and allowed those dealing with bolted joints to assemble the variables by methods that had been used successfully for many years by many people. This document is helping people across industry not only to assemble bolted flange joints, but also to establish joint integrity programs, procedures, and best practices. PCC-1-2010 shifts the emphasis to gasket stress and gasket type and provides instruction and information pertinent to bolt torque values. The 2010 document contains, for instance, a whole section on bolt stress—the unit load that should be put on the bolts—and includes tables as well.

Determination of Target Bolt Tension for Flanges With Lens Gaskets

2017 ◽  
Author(s):  
Gys van Zyl
Keyword(s):  
Iterative Process ◽  
Line Contact ◽  
Flange Joint ◽  
Element Analysis ◽  
Special Challenge ◽  
Metallic Ring ◽  
High Integrity ◽  
European Standards ◽  
Bolted Flange

A lens gasket is a specific type of metallic ring gasket that is usually only deployed in high pressure gas applications where a high integrity bolted flange joint is required. Lens gaskets are not common in ASME design and there are no ASME rules that guide the design of flanges with lens gaskets, nor are there ASME standards to control lens gasket specifications. Lens gaskets present a special challenge when determining target bolt tension values for flange assembly. For calculating target bolt tension, the gasket seating width is an important parameter. With lens gaskets, the gasket seating width depends on the applied bolt tension, therefore calculation of bolt tension is by nature an iterative process. In these flange joints, the lens gasket has spherical machined surfaces that are in contact with conical gasket seats in the flanges. At low bolt tensions, gasket contact is nearly equivalent to line contact. At high bolt tensions, finite contact widths are developed, sometimes involving plastic deformation of the gasket. This paper will present a method that was developed to determine target bolt tension for a lens gasket bolted flange. Reference will be made to European standards that address lens gaskets, and the results of finite element analysis studies that were used to validate the calculation method will be presented. The successful deployment of the outcome of this work for all the lens gasket flange joints on a plant will be discussed.

A new method for the determination of nitrates

1960 ◽  
Vol 23 ◽  
pp. 227-232 ◽  
Author(s):  
P WEST ◽  
G LYLES
Keyword(s):  
New Method

A New Method for the Determination of Plasma Activators of Fibrinolysis

1977 ◽  
Vol 37 (02) ◽  
pp. 210-215 ◽  
Author(s):  
R Margalit ◽  
E Gidron ◽  
Y Shalitin
Keyword(s):  
New Method ◽  
Effective Activator

SummaryThe term “effective activator” of plasminogen is proposed, to denote the resultant of activator-antiactivator interaction, and a method for the determination of the level of these activators is described. By adding axcess plasminogen to the euglobulin fraction of plasma the influence of the level of endogenous plasminogen and of the antiplasmin is eliminated. It is shown that the level of fibrinogen has very little bearing on the results. An effective activator unit is defined as equal to 1 CTA unit of urokinase activity on a fibrinogen-plasminogen substrate.

The Plasmin Inhibitors of Plasma

1964 ◽  
Vol 12 (01) ◽  
pp. 119-125 ◽  
Author(s):  
Y Shamash ◽  
A Rimon
Keyword(s):  
Human Plasma ◽  
New Method ◽  
Normal Amount ◽  
Caseinolytic Activity ◽  
Before And After ◽  
Plasmin Inhibitors

SummaryA new method for the assay of plasmin inhibitors in human plasma is described. The method consists of determination of the caseinolytic activity of a standard plasmin solution before and after incubation with the inhibitor, with lysine added to the mixture as a stabilizer of plasmin. Using this method, it was found that plasma contains enough inhibitors to inactivate 30 caseinolytic units of plasmin, or 10 times the normal amount of plasminogen in human plasma.

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