Performance of a Gasketed Bolted Flange Joint Under Combined Structural and Thermal Transient Loading (Taking Bolt Scatter Into Consideration): FEA Approach

2009 ◽  
Author(s):  
Muhammad Abid ◽  
Kamran Ahmed Khan ◽  
Javed Ahmad Chattha
Keyword(s):  
Element Model ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Flange Joint ◽  
Transient Loading ◽  
Sealing Performance ◽  
Need To Evaluate ◽  
Thermal Transient ◽  
Temperature And Pressure ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. The weakest part of a high temperature and pressure envelope is the gasket in bolted flange joints, as these are prone to leakage. It causes loss of productivity and in severe cases, loss of lives. There is a need to evaluate the sealing performance of a gasketed bolted flange joint (GBFJ) under combined structural and thermal transient loadings as these occur in industrial applications. In this paper using complete 3D Finite Element Model, the joint’s performance is studied during bolt up and operating (combined structural and thermal transient loading) condition. During bolt up, bolts are tightened as per ASME bolt up strategy and any bolt scatter and its effect during applied operating conditions is discussed.

Finite Element Analysis of a Gasketed Flange Joint Under Combined Internal Pressure and Thermal Transient Loading

2007 ◽  
Author(s):  
Muhammad Abid ◽  
Javed A. Chattha ◽  
Kamran A. Khan
Keyword(s):  
Finite Element Analysis ◽  
Steady State ◽  
Internal Pressure ◽  
Thermal Loading ◽  
Flange Joint ◽  
Element Analysis ◽  
Transient Loading ◽  
Thermal Transient ◽  
Transient Thermal ◽  
Bolted Flange

Performance of a bolted flange joint is characterized mainly by its ‘strength’ and ‘sealing capability’. A number of analytical and experimental studies have been conducted to study these characteristics only under internal pressure loading. In the available published work, thermal behavior of the pipe flange joints is discussed under steady state loading with and without internal pressure and under transient loading condition without internal pressure. The present design codes also do not address the effects of steady state and thermal transient loading on the structural integrity and sealing ability. It is realized that due to the ignorance of any applied transient thermal loading, the optimized performance of the bolted flange joint can not be achieved. In this paper, in order to investigate gasketed joint’s performance i.e. joint strength and sealing capability under combined internal pressure and transient thermal loading, an extensive nonlinear finite element analysis is carried out and its behavior is discussed.

Application of Plastic Region Bolt Tightening to Flange Joint Assembly: Behavior of Large Diameter Flange

2009 ◽  
Author(s):  
Shinobu Kaneda ◽  
Hirokazu Tsuji
Keyword(s):  
Internal Pressure ◽  
Large Diameter ◽  
Plastic Region ◽  
Load Factor ◽  
Past Study ◽  
Flange Joint ◽  
The Past ◽  
Sealing Performance ◽  
Assembly Behavior ◽  
Bolted Flange

In the past study the plastic region tightening has been applied to the bolted flange joint with smaller nominal diameter and its advantages have been demonstrated, however, behavior of the bolted flange joint with larger diameter is not investigated. Flange rotation of the bolted flange joint with large diameter increases when the internal pressure is applied. Gasket stress is not uniform and it may cause leak accident. So, it is necessary to investigate the behavior of the larger diameter flange. The present paper describes the behavior of bolted flange joint with large diameter under plastic region tightening. Firstly, API 20-inch flange joint tightened to the plastic region by bolt with a smaller diameter and superiority in the uniformity of the axial bolt force is demonstrated. And then the internal pressure is applied to the bolted flange joint and the behavior of the additional axial bolt force is demonstrated. The axial bolt force decreases with increasing the internal pressure, and the load factor is negative due to increasing of the flange rotation. However, the load factor of the bolted flange joint tightened to the plastic region by using the bolt with the smaller diameter approached zero. Using the bolts with smaller diameter is advantageous to the flange joint with the larger diamter, whose load factor is negative, to prevent the leakage. Additionally, the leak rate from the bolted flange joint is measured and the sufficient sealing performance is obtained.

Evaluation of Flow Behavior for Clearance Brush Seals

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Yahya Dogu ◽  
Mahmut F. Aksit ◽  
Mehmet Demiroglu ◽  
Osman Saim Dinc
Keyword(s):  
Flow Field ◽  
Flow Behavior ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Brush Seal ◽  
Sealing Performance ◽  
Computational Fluid Dynamics Analysis ◽  
Flow Features ◽  
Brush Seals ◽  
Initial Clearance

The industrial applications of brush seals have been increasing due to their superior sealing performance. Advances in the understanding of seal behavior have been pushing the design limits to higher-pressure load, temperature, surface speed, and rotor excursion levels. The highest sealing performance can be achieved when the bristle pack maintains contact with the rotor surface. However, due to many design and operational constraints, most seals operate with some clearance. This operating clearance cannot be avoided due to rotor runouts, transient operating conditions, or excessive bristle wear. In some applications, a minimum initial clearance is required to ensure a certain amount of flow rate for component cooling or purge flow. Typically, brush seal failure occurs in the form of degraded sealing performance due to increasing seal clearance. The seal performance is mainly characterized by the flow field in close vicinity of the bristle pack, through the seal-rotor clearance, and within the bristle pack. This work investigates the flow field for a brush seal operating with some bristle-rotor clearance. A nonlinear form of the momentum transport equation for a porous medium of the bristle pack has been solved by employing the computational fluid dynamics analysis. The results are compared with prior experimental data. The flow field for the clearance seal is observed to have different characteristics compared to that for the contact seal. Outlined as well are the flow features influencing the bristle dynamics.

Effects of Nut Thinning due to Corrosion on the Strength Characteristics and the Sealing Performance of Bolted Flange Joints Under Internal Pressure

2011 ◽  
Author(s):  
Tsutomu Kikuchi ◽  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Internal Pressure ◽  
Yield Stress ◽  
Strength Characteristic ◽  
Small Scale ◽  
Screw Thread ◽  
Flange Joint ◽  
Bearing Surface ◽  
Sealing Performance ◽  
Bolted Flange ◽  
Screw Threads

The effects of nut thinning due to corrosion on the strength characteristic and the sealing performance in 3B bolted flange joints under internal pressure are examined from both FEM calculations and experiments. The following results are obtained. When bolts and nuts in a bolted flange joint are tightened with 50% of yield stress, no yield region at the engaged screw thread occurs, however, when they arc tightened with 90% of the yield stress, a small scale yield region occurs at the roots of the engaged three screw threads from the bearing surface of the nut. While verifying this phenomenon using FEM, it was newly discovered that when the height of the nut was reduced to 1/3 (equivalent to approximately two threads) of the original dimensions according to the standards, the sealing performance could no longer be assured.

Sealing Performance Evaluation for Bolted Flange Joint with Spiral Wound Gasket Based on the Bolt Force

2019 ◽  
Vol 795 ◽  
pp. 246-253
Author(s):  
Fa Kun Zhuang ◽  
Xiao Peng Li ◽  
Guo Shan Xie ◽  
Jin Shi ◽  
Yian Wang
Keyword(s):  
Performance Evaluation ◽  
Internal Pressure ◽  
Chemical Plant ◽  
Leakage Rate ◽  
Flange Joint ◽  
Rate Model ◽  
Rate Parameter ◽  
Sealing Performance ◽  
Bolted Flange ◽  
The Relationship

Leakage accidents often occur at the bolted flange joints, which are widely used in the petro-chemical plant. This is mainly resulted by the reduction of bolt force during operation. Therefore, bolt force is very important for sealing performance of the joints in service. Based on the leakage rate parameter, the relationship between the bolt force and gasket stress was derived. Moreover, the leakage rate model was established on the basis of bolt force. With this model, the leakage rate can be directly calculated through the bolt force, and the sealing performance can be evaluated. In order to verify this model, corresponding experiments have been performed. It shows that with the internal pressure increasing, the bolt force increases and the gasket stress reduces. There exists a monotonic relationship between the bolt force and gasket stress. The theoretical gasket stress value corresponds well with the experimental value. The calculated leakage rates for the joints also agree well with the experimental value. Then, it is feasible to evaluate the sealing performance for the bolted flange joints based on the bolt force.

New Simplified Dynamic Modeling Method of Bolted Flange Joints of Launch Vehicle

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Gang Li ◽  
Zhaokun Nie ◽  
Yan Zeng ◽  
Jiacheng Pan ◽  
Zhenqun Guan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Static Analysis ◽  
Dynamic Modeling ◽  
Element Model ◽  
Launch Vehicle ◽  
Modeling Method ◽  
Flange Joint ◽  
Longitudinal Response ◽  
Bolted Flange

Abstract The bolted flange joint is an important source of nonlinearity in dynamical analysis of launch vehicles, which will lead to both longitudinal and transversal responses simultaneously subject to transversal dynamic loads, and may result in the failure of the connection structure. In this paper, a novel simplified dynamic modeling method via structural static analysis is proposed to simulate dynamical response of nonlinear bolted flange joints of launch vehicle, in which only static analysis of the detailed finite element model or static experiment is used for parameter identification of the model. Two types of nonlinear springs are designed for different tensile and compressive stiffness of the bolted flange joint, which affect longitudinal dynamic behaviour of the connection, and a shear spring is used to modify the transversal stiffness. The sections of launch vehicle are modeled as linear beams for efficiency. Effectiveness of the proposed modeling method is confirmed by a typical connection structure, bolted flange connected cylindrical shells, whose finite element models are verified with dynamic experiments. Superiority of the simplified dynamic model from the proposed method is demonstrated by comparing with the previous simplified model. The connection structures with different numbers of bolts are studied, and most of the dynamic responses calculated from the proposed model agree well with those from the finite element model. The coupling vibration of the connection structure is predicted successfully, in which longitudinal response of the structure is excited by the transversal load.

Behavior of Flange Joints Under Combined Internal Pressure and Thermal Loading: The Case of Using Metal-to-Metal Contact Type Gaskets

2013 ◽  
Author(s):  
Kai Ma ◽  
Yi Zhang ◽  
Lanzhu Zhang ◽  
Kaishu Guan
Keyword(s):  
Internal Pressure ◽  
Nuclear Power ◽  
Thermal Loading ◽  
Three Dimensional ◽  
Element Model ◽  
Metal Contact ◽  
Flange Joint ◽  
Contact Type ◽  
Bolted Flange ◽  
Nonlinear Finite Element Model

In a bolted flange joint, metal-to-metal contact type gasket takes over only part of the bolt load to achieve seating stress, and the additional bolt load is transmitted to the metal-to-metal contact to compensate for the unloading effects due to internal and external loadings. Due to this advantage, flange joints with metal-to-metal contact type gaskets are gradually used in chemical industry, nuclear power industry, etc. A three-dimensional nonlinear finite element model is developed to highlight the complex behavior of the flange joint with metal-to-metal contact type gasket under combined internal pressure and thermal loading. Despite of the common perception that the gasket stress in the metal-to-metal contact type gasket stays constant, reduced gasket stress is concluded due to flange rotation and joint thermal expansion.

scholarly journals Measurements of Density and Sound Speed in Mixtures Relevant to Supercritical CO2 Cycles

2020 ◽  
Vol 142 (10) ◽  
Author(s):  
Suhyeon Park ◽  
Justin Urso ◽  
K.R.V. (Raghu) Manikantachari ◽  
Ashvin Hosangadi ◽  
Andrea Zambon ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sound Speed ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
Frequency Detection ◽  
Temperature And Pressure ◽  
Power Generation Systems ◽  
Piezoelectric Pressure Sensor

Abstract The objective of this research is to validate properties of mixtures relevant to supercritical carbon dioxide (sCO2) power cycles. Direct-fired sCO2 cycles are a promising technology for the future power generation systems. The working fluid of sCO2 cycles will be near and above critical point of CO2. One of the challenges is that the simulation of mixtures should consider real gas behavior. Expected operating conditions of Allam cycles reach up to 300 bar and 1000 °C. Characterizing the mixtures at the extreme conditions is an important issue in current researches and industrial applications. Thermophysical properties of mixtures may be beyond the valid range of the widely used database such as NIST REFPROP. Experimental data of mixture properties in the literature are limited which is necessary to develop high-fidelity design tools for sCO2 power cycles. We measured the density and sound speed of several multi-component mixtures. A temperature-controlled high-pressure test cell was used for the density measurements. Sound speed was measured by resonant frequency detection using an external speaker and a piezoelectric pressure sensor. Mixtures studied in this work include carbon dioxide, methane, oxygen, and water vapor. Properties of pure CO2 were measured to show the validity of our technique. Compositions were selected to be close to frozen mixtures at the inlet, mid-progress, and exhaust conditions of a model sCO2 combustor in the previous numerical simulation work. Corresponding reaction progress variables (RPV) were RPV = 0, 0.5, and 1. Temperature and pressure conditions of experiments are 310–450 K and 0–150 bar. In our study, density and sound speed from the NIST REFPROP database agree with experimental measurements within the range of our measurement uncertainties.

Measurements of Density and Sound Speed in Mixtures Relevant to sCO2 Power Cycles

2020 ◽  
Author(s):  
Suhyeon Park ◽  
Justin Urso ◽  
K. R. V. (Raghu) Manikantachari ◽  
Ashvin Hosangadi ◽  
Andrea Zambon ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Sound Speed ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Working Fluid ◽  
Power Cycles ◽  
Frequency Detection ◽  
Temperature And Pressure ◽  
Power Generation Systems ◽  
Piezoelectric Pressure Sensor

Abstract The objective of this research is to validate properties of mixtures relevant to supercritical carbon dioxide (sCO2) power cycles. Direct fired sCO2 cycles are promising technology for the future power generation systems. The working fluid of sCO2 cycles will be near and above critical point of CO2. One of the challenges is that the simulation of mixtures should consider real gas behavior. Expected operating conditions of Allam cycles reach up to 300 bar and 1000 °C. Characterizing the mixtures at the extreme conditions is an important issue in current researches and industrial applications. Thermophysical properties of mixtures may be beyond the valid range of the widely used database such as NIST REFPROP. Experimental data of mixtures properties in the literature is limited which is necessary to develop high-fidelity design tools for sCO2 power cycles. We measured density and sound speed of several multi-component mixtures. A temperature-controlled high-pressure test cell was used for the density measurements. Sound speed was measured by resonant frequency detection using an external speaker and a piezoelectric pressure sensor. Mixtures studied in this work includes carbon dioxide, methane, oxygen and water vapor. Properties of pure CO2 were measured to show the validity of our technique. Compositions were selected to be close to frozen mixtures at the inlet, mid-progress and exhaust conditions of a model sCO2 combustor in the previous numerical simulation work. Corresponding reaction progress variables (RPV) were RPV = 0, 0.5, and 1. Temperature and pressure conditions of experiments are 310–450 K, and 0–150 bar. In our study, density and sound speed from NIST REFPROP database agree with experimental measurements within the range of our measurement uncertainties.

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