Gaskets in joints play an important role in the sealing performance of bolted flange joints, and their behavior is complex due to nonlinear material properties combined with permanent deformation. The variation of contact stresses due to the pressure of the flange and the material properties of the gasket play important roles in achieving a leak proof joint. In this paper, a three-dimensional finite element analysis (FEA) of bolted flange joints has been carried out by taking experimentally obtained loading and unloading characteristics of the gaskets for various thicknesses and loads. Analysis shows that the distribution of contact stress has a more dominant effect on sealing performance than the limit on flange rotation specified by ASME.

1. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 46
A Study and Analysis of Sealing Performance of Bolted Flange
Jointwith Gaskets using Finite Element Analysis
Wasim B. Patel1
,Ritesh G. Deokar2
,Pundlik N. Patil3
,Raghunath Y. Patil4
,
1*(PG Scholar, Department of Mechanical Engineering, SGDCOE,North Maharashtra University, Jalgaon.)
2 (UG Scholar, Department of Mechanical Engineering, MIT, Savitribai Phule Pune University, Pune.)
3,4 (Asso. Prof. Department of Mechanical Engineering, SGDCOE, North Maharashtra University, Jalgaon)
I. INTRODUCTION
Due to simple dismounting bolted flanged joints
are the most popular means of connecting piping
systems and pressure vessels containing fluid or gas
under pressure. Although this type of connection is
practical in terms of disassembly, it is a source of
potential leakage failure especially when operating
under high pressures and temperatures.
A gasket is used to create and retain a static seal
between two stationary flanges, which connect
series of mechanical assemblies in an operating
plant, containing a wide variety of fluids. These
static seals aim to provide a complete physical
barrier against the fluid contained within, and so
block any potential leakage path. To achieve this,
the gasket must be able to flow into (and fill) any
irregularities in the mating surfaces being sealed,
while at the same time be sufficiently resilient to
resist extrusion and creep under operating
conditions. The seal is affected by the action of
force upon the gasket surface, which compresses
the gasket, causing it to flow into any flange
imperfections.
A.The modern sealing challenge
Historically, compressed asbestos fiber sheet
material has been the material of choice for "soft"
gasket materials. It was regarded as easy to use and
very tolerant of abuse, for which it was recognized
as very "forgiving". Consequently, the material was
used to seal almost all common applications, and
usually gave reasonable performance. A broad
experience of the material was established over
many years amongst manufacturers and users alike.
Similarly, testing specifications for traditional
soft gasket materials were intended for application
to asbestos-based materials where there was a large
area which indicated that such materials would
perform satisfactorily in service, provided that they
were manufactured under an appropriate level of
quality control. some of the properties measured by
such quality control tests were of direct functional
importance. Rather, they provided assurance that
the current batch was similar to its predecessors in
composition and therefore, by implication, in
performance.
II. METHODOLOGY
To carried out the comparative analysis of contact
stresses between the joint by experimentally and by
FEM ,following are the steps to be followed out:
Step 1. The detailed FEM model of the single
bolt joint is built, completely reflecting geometry of
the bolt and fragment of the flange. Contact
interactions between elements are taken into
RESEARCH ARTICLE OPEN ACCESS
Abstract:
Gaskets in joints play an important role in the sealing performance of bolted flange joints, and their behavior is
complex due to nonlinear material properties combined with permanent deformation. The variation of contact stresses due to
the pressure of the flange and the material properties of the gasket play important roles in achieving a leak proof joint. In this
paper, a three-dimensional finite element analysis (FEA) of bolted flange joints has been carried out by taking experimentally
obtained loading and unloading characteristics of the gaskets for various thicknesses and loads. Analysis shows that the
distribution of contact stress has a more dominant effect on sealing performance than the limit on flange rotation specified by
ASME.
Keywords — Bolted Flanged joints,Gaskets,FEA,Von-Misses stresses.

2. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 47
consideration in the model, the friction on the
thread and the elastic-plastic model of the material
included.
Step 2. Parameters like loads, pressure of the
equivalent bolt joint model are defined.
Step 3. The global model of the flange joint is
built with equivalent elements. Contact phenomena
and
Clamping force of the bolt joint are taken into
consideration. Generalized sectional forces are
assigned for individual bolts {F}, for representative
sets of loads.
Step 4. Generalized extreme sectional forces
{F}max and{F}min are applied to the detailed
model. Fields of stresses in the bolt joint are
obtained from the performed calculations.Tensors
are determined: average stress , stress amplitude
and stress range . Equivalent values: average
stress,stress amplitude and stress range are
calculated according to the Huber – von Misses
hypothesis
Step 5.Final estimate of the flange joint. Fatigue
analysis is carried out based on the previously
determined values with numerical or classical
methods or experimental method.
III. EXPERIMENTAL SET UP
Fig 1: Experimental setup
Equipment to be used during testing shall have
suitable capacity for the range of test pressures
required. Pressure indicators shall have a full-scale
range between 110 percent and 150 percent of test
pressure and an accuracy and sensitivity of 2
percent of full-scale reading. If we required
hydrostatic testing of carbon steel piping systems
the test medium shall be potable water at ambient
temperature with pH value between 6 and 7. In
accordance with ASME B31.3 the minimum
hydrostatic test pressure at any point in the
systemshall be:
a. 1.5 times the design pressure, or
b. calculated in accordance with formula
specified in ASME B31.3 if the design temperature
is above the test temperature.
IV. COMPUTATIONAL SETUP OF FINITE
ELEMENT ANALYSIS
Fig 2: Geometry with seal 5mm
To validate the analytical model that estimates
the relaxation of the bolt and the gasket, three-
dimensional numerical FE models were constructed
on each of these assemblies in Ansys 14.0 which is
a commercial structural analysis software based on
the finite element technique, was used for this
purpose. Because of symmetry with respect to the
plane that passes through the gasket mid-thickness
and evenly repeated loading in the angular direction,
it is possible to model only an angular portion (Fig.)
that includes half of the bolt and half of the gasket
thickness.
A. Mesh Generation
The finite element meshes for flange and bolt
were created with the help of Altair Hypermesh tool
which is a Mechanical meshing tool. Since the
geometries of theflange and bolt models are

3. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 48
complex, an unstructured hexahedral-dominant
techniquewas used to mesh. Hexahedral-dominant
means that themeshing tool tries to create a mesh
consisting of hexahedral elements. The single order
hexahedron elements were generated with the help
of Hypermesh tool with better element quality.A
good quality element refers to an element that is not
excessively distorted in shape. Element quality is
determined by two factors: default shape checking
metric; and the Jacobian ratio. The Jacobian ratio is
used to map an ideal finite-element on to the real
finiteelement. The Jacobian ratio is the ratio of the
maximum determinant to the minimum determinant
evaluated at these points and has a limit of 0.5.Both
quality factors have a value of unity for an
undistortedhexahedral element.To reduce distortion
of the element in such instances, either the mesh
can be refined, or another element shape that meets
the shape checking criteria can be employed.
Fig 3: Assembly Mesh
V. RESULT AND DISCUSSIONS
A. Stress Distribution in the gasket for three cases
Fig 4. Von-Misses stress contour plot – Gasket 5mm
Fig 5. Von-Misses stress contour plot – Gasket 4mm
Fig 6. Von-Misses stress contour plot – Gasket 3mm
The 5 mm gasket shows maximum von-Mises
stress up to 73.27 MPa which is under the limit of
maximum allowable stress of 80 MPa. The 5 mm
gasket is not yielding beyond allowable stress for

4. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
ISSN: 2395-1303 http://www.ijetjournal.org Page 49
applied loading scenario. The 4 mm gasket shows
maximum von-Mises stress upto 84.82 MPa which
is slightly greater than yield strength of the material.
The 3 mm gasket shows maximum von-mises
stress more than 93.55 MPa which is more than the
yield strength of the material. Therefore, the gasket
is safe for first case (for 5 mm in size) in applied
structural loading conditions. The stresses at flanges,
bolt and nut where within limit. Therefore, 5mm
thickness gasket is most suitable for the application.
B. Maximum Displacement of Gasket
The maximum displacement of the gasket
observed due to compressive load of the flange
upper and lower housing. The displacement contour
plots are shown in the below figure. The gasket
shows displacement up to 0.4 mm for 5 mm
thickness.
Fig 7. Maximum Displacement contour plot – 5mm gasket
C. Graphs
Fig 8: Deformation of Gasket - Thickness 5mm
Fig 9: Deformation of Gasket - Thickness 4mm
Fig 10: Deformation of Gasket - Thickness 3mm

5. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
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D. Result table
TABLE I
VI. CONCLUSION
A finite element analysis was performed to
investigate the leakage and structural integrity of
the bolted flange joint assembly for the design
conditions for bolt preload and internal pressure 69
MPa. The deformation of the flange and bolt was
studied when subjected to these external loads. This
deformation is responsible to induce the stresses in
the gasket so that it may get compressed. I t was
also determined that, the difference between FEA
and experimental values are less than 10%. So, it is
concluded that, the 5 mm thickness of the gasket is
structurally safe to use in the flange and the bolt.
The experimental and FEA results are reported in
the table. The other parts in the assembly like
flanges, nut and bolt exerts minimum stresses that
are within yield strength (350 MPa) of the material.
ACKNOWLEDGMENT
The compilation of this paper would not have
been possible without the support and guidance of
Mr. P. N. Patil with my deep sense of gratitude. My
deep and most sincere feeling of gratitude to the
Head of Department Mr. R. Y. Patil who very
kindly allowed me to work on this interesting topic.
At last I am thankful to my Father, Mother and
Brother for their valuable support to me for
completion of paper.
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Description FEA Results Experimental
Results
Deflection
(mm)
Von-
Misses
stress
(MPa)
Defle
ction
(mm)
Von-
Misses
stress
(MPa)
1 Gasket –
5mm
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2 Gasket –
5mm
0.46 84.82 0.5 90
3 Gasket –
5mm
0.48 93.55 0.55 110

6. International Journal of Engineering and Techniques - Volume 2 Issue 1, Jan - Feb 2016
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