A Model for the Static Sealing Performance of Compliant Metallic Gas Seals Including Surface Roughness and Rarefaction Effects

Purpose The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS). Design/methodology/approach The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed. Findings The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance. Originality/value The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

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Tubing String Thread Sealing Surfaces Damage Evaluation Based on Acoustic Elasticity Theory

Materials Science Forum ◽

10.4028/www.scientific.net/msf.944.828 ◽

2019 ◽

Vol 944 ◽

pp. 828-834 ◽

Cited By ~ 2

Author(s):

Jian Jun Wang ◽

Jian Hua Sun ◽

Shang Yu Yang ◽

Yao Rong Feng ◽

Kai Lin

Keyword(s):

Surface Roughness ◽

Elasticity Theory ◽

Contact Stress ◽

Surface Characterization ◽

Surface Damage ◽

Center Frequency ◽

Sealing Performance ◽

Tubing String ◽

Acoustic Elasticity

During the processing of tubing premium threaded made up, the degree of the thread sealing surface intactness will directly affect the sealing performance of the string. Nevertheless, there are some difficulties to detect the damage of the engaged sealing surface effectively. In the present study the sealing surface damage was judged by the sealing surface contact stress’s relative changes according to the acoustic elasticity theory,. At the same time, the wear defects generated at the tubing sealing surface, during the tubing made up, contrasted with the wear and unworn surface roughness of coupling ultrasonic detected about the sealing surface. The results showed that with the acoustic amplitude evaluated the sealing contact stress was susceptible to the influence of surface roughness of coupling. But the reflection wave with the center frequency on the sealing surface characterization of the contact stress could avoid this problem effectively.

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Effect of surface roughness on sealing performance of silicone rubber

Emerging Materials Research ◽

10.1680/jemmr.16.00084 ◽

2019 ◽

Vol 8 (1) ◽

pp. 62-67 ◽

Cited By ~ 1

Author(s):

Jian Wu ◽

Jiyi Dong ◽

Chuncai Xu ◽

Youshan Wang

Keyword(s):

Surface Roughness ◽

Silicone Rubber ◽

Sealing Performance ◽

Effect Of Surface

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Paper 6: Assessment of Face Seal Performance Based on the Parameters of a Statistical Representation of Surface Roughness

Proceedings of the Institution of Mechanical Engineers Conference Proceedings ◽

10.1243/pime_conf_1967_182_308_02 ◽

1967 ◽

Vol 182 (11) ◽

pp. 101-107 ◽

Cited By ~ 1

Author(s):

L. A. Mitchell ◽

M. D. Rowe

Keyword(s):

Surface Roughness ◽

Standard Deviation ◽

Surface Profile ◽

Real Surface ◽

Face Seal ◽

Statistical Representation ◽

Adequate Information ◽

Centre Line ◽

Sealing Performance ◽

The Mean

Most methods commonly used to describe real surface roughness do not provide adequate information to enable predictions to be made of fluid leakage between two surfaces. To carry out such an analysis it is essential to know the depths of the remaining valleys at all stages of compression. It is shown that, when the distributions of peak and valley levels are defined, load-compression and load-leakage relationships can be derived if wedge-shaped asperities of constant apex semi-angle are assumed. The results suggest that a convenient quantity for specifying the form of a surface profile is the ratio of the distance between the mean peak and mean valley levels to the standard deviation of the distributions ( d/σ). For the best sealing performance d/σ should be as large as possible, whilst the centre-line average (c.l.a.), which provides a measure of the scale of the roughness, should be as small as possible.

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Dynamic characteristics and transient sealing performance analysis of hyperelliptic curve groove dry gas seals

Tribology International ◽

10.1016/j.triboint.2017.07.017 ◽

2017 ◽

Vol 116 ◽

pp. 217-228 ◽

Cited By ~ 7

Author(s):

Yuan Chen ◽

Jinbo Jiang ◽

Xudong Peng

Keyword(s):

Performance Analysis ◽

Dynamic Characteristics ◽

Hyperelliptic Curve ◽

Sealing Performance ◽

Gas Seals

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Sealing Performance Layered Metal Gasket Based on the Simulation Method

Teknik ◽

10.14710/teknik.v41i1.26125 ◽

2020 ◽

Vol 41 (1) ◽

pp. 14-19

Author(s):

I Made Gatot Karohika ◽

Shigeyuki Haruyama ◽

I Nyoman Gde Antara ◽

I Nyoman Budiarsa ◽

I Made Dwi Budiana Penindra

Keyword(s):

Surface Roughness ◽

Base Material ◽

Simulation Method ◽

Element Analysis ◽

Elastic Mode ◽

Sealing Performance ◽

Contact Width ◽

Covering Material ◽

Corrugated Metal ◽

Surface Covering

Studies for corrugated metal gaskets are still ongoing to improve its performance. This is considered to be a single gasket with SUS304 material when contact with flanges that have greater surface roughness, reduced contact width and plastic deformed contact surfaces are incomplete and cannot fill the surface roughness of flanged flanges. The use of softer material than the base material as a surface covering material is used to improve the performance of the gasket. In this study, therefore the effect of modulus of elasticity ratio and thickness ratio on contact width and contact stress, 25A three-layer metal gasket was investigated using Finite Element Analysis. The results showed that the material with tangent modulus, Ehal = Eal / 150 had the highest slope for contact width. While the contact width of the plastic mode gasket is higher than the elastic mode gasket.

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FEM Stress Analysis and the Sealing Performance Evaluation of Bolted Flanged Connections With Metal Flat Gaskets

Volume 2: Computer Technology and Bolted Joints ◽

10.1115/pvp2013-97828 ◽

2013 ◽

Author(s):

Koji Kondo ◽

Shota Tsubaki ◽

Toshiyuki Sawa ◽

Yuya Omiya ◽

Koji Sato

Keyword(s):

Surface Roughness ◽

Stress Analysis ◽

Contact Area ◽

Metal Contact ◽

Stress Distributions ◽

Test Taking ◽

Sealing Performance ◽

Metal Metal ◽

Higher Temperature ◽

Behavior Test

Metal gaskets have been used in bolted flanged connections under higher pressure and higher temperature conditions. However, it is difficult to estimate the sealing performance of the metal contact interfaces in the connections. Thus, it is necessary to study on the sealing characteristics of the metal to metal contact gasket in the connections under higher internal pressure and higher temperature. In this study, firstly, the sealing behavior test taking into account load history is carried out in detail using metal flat gaskets according to JIS B2490. Secondly, to examine the effect of the gasket contact area and surface roughness of metal gasket on the sealing behavior of metal-metal contact, the sealing behavior test is carried out using metal flat gaskets which has several types of gasket width and surface roughness. Thirdly, the amount of leakage is measured for bolted flanged connections with metal flat gaskets. The relationship between the gasket contact stress and the leak rate is obtained. Furthermore, the contact gasket stress distributions in the connection are analyzed using FEM stress analysis. Using the obtained gasket stress distribution, the sealing performance is estimated taking into account the gasket contact area and surface roughness of the metal flat gasket. The estimated result is compared with the measured results. In the results, the effect of the yield stress and the plastic deformation of the gasket surface are found to be important on the sealing mechanism.

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The Sealing Characteristics of Bolted Flanged Connection With Metal Gasket

Volume 2: Computer Technology and Bolted Joints ◽

10.1115/pvp2012-78413 ◽

2012 ◽

Author(s):

Koji Kondo ◽

Toshiyuki Sawa ◽

Koji Sato ◽

Tsutomu Kikuchi ◽

Shota Tsubaki

Keyword(s):

Surface Roughness ◽

High Temperature ◽

Room Temperature ◽

Testing Machine ◽

Fem Analysis ◽

Material Testing ◽

Metal Contact ◽

Stress Distributions ◽

Sealing Performance ◽

Material Testing Machine

Metal gaskets have been used in bolted flanged connections under high pressure and high temperature conditions. However, it is difficult to estimate an amount of leakage from the metal contact interfaces in the connections. Recently, it has been noticed that a tiny leakage occurs from the gasket interfaces in bolted flanged connections. Thus, it is necessary to study on the sealing characteristics of the metal to metal contact gasket in the connections under internal pressure and high temperature. In the present paper, for clarifying the characteristic of the metal gaskets, some experiments were conducted at room temperature. The gaskets are used aluminum, copper and mild steel flat gaskets. Firstly, according to JIS B 2490, the sealing behavior was measured taking account the surface roughness of the metal gaskets. The gaskets were compressed using a material testing machine while the amount of leakage was measured. Secondly, the amount of leakage was measured for bolted flanged connections with metal gaskets. The flange nominal diameter used was 2″. Finally, the contact gasket stress distributions in the connection were analyzed using 3-D FEM analysis. Using these results, discussion was made on the sealing behavior of the metal gaskets. In the result, it is found that plastic strain is important for the sealing performance of the metal gasket.

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Effects of Surface Roughness and Slip Flow on the Performance of a Spiral Groove Gas Face Seal

First International Conference on Integration and Commercialization of Micro and Nanosystems, Parts A and B ◽

10.1115/mnc2007-21443 ◽

2007 ◽

Cited By ~ 2

Author(s):

Xu-Dong Peng ◽

Song-En Sheng ◽

Xiao-Ni Yin ◽

Ji-Yun Li

Keyword(s):

Surface Roughness ◽

Standard Deviation ◽

Slip Flow ◽

Element Model ◽

Face Seal ◽

Spiral Groove ◽

Sealing Performance ◽

Set Up ◽

Gas Face Seal ◽

Effect Of Surface

Considering the effects of surface roughness and slip flow, the extended Reynolds equation presented by Makino et al [1] is used to set up the finite element model for a non-contact spiral groove dry gas face seal (S-DGS). The analyses for a typical S-DGS at low speed (≤ 500 rpm) and low pressure (≤ 0.606 MPa) showed that the effect of slip flow on the sealing performance is significant for 0.05≤ Kn < 1.0, where Kn refers to the Knudsen number, but the effect of surface roughness on the sealing performance varies with the different areas of both the two faces. When the standard deviation of composite roughness is less than 1.0 micron and in the range of 0.5≤ Kn≤ 1.0, the effects of surface roughness and slip flow diminished on gas film stiffness and frictional work but are still significant on the leakage rate. The effect of surface roughness of the spiral groove bottom is significant and should be considered, but the effects of the other surface roughness, i.e. the soft ring surface roughness and the un-grooved hard ring surface roughness, are negligible only when the value of the standard deviation of composite roughness meets with API standards.

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