Bolted Pipe Flange Connections Research Articles

Analysis on the Leakage of the Flange Connection of the Water-Containing Hydrofluoric Acid Pipeline

Leakages of bolted pipe flange connections of water-containing hydrofluoric acid pipelines were frequently reported by the extraction section in the fluorine chemical industry. Water-containing hydrofluoric acid can cause severe injuries to human beings due to its strong causticity. The water-containing hydrofluoric acid pipe was a short lined pipe, so a lot of flange connections and supports were adopted in the pipeline. In this paper, the finite element models of the pipeline were established to analyze the internal force of the pipeline under conditions including internal pressure, temperature, self-weight, and so on. Based on this, the equivalent design pressure of the flange connections was determined. The results of the stress analyses of the pipeline showed that leakages were mainly caused by a large bending moment, due to the unreasonable layout of the piping supports under self-weight. When the pipeline was supported on the beam of the pipe gallery, which is not necessarily beneficial to reduce the bending moment of the pipeline, and the flange connection was close to the supporting beam at the same time, leakages frequently occurred in this flange connection. To support the pipeline reasonably, the flange connection should be placed at zero bending moment positions. Therefore, the positions with zero bending moments of the pipeline with equal and unequal spacing supports were obtained under gravity load, to provide a basis for the rational support of lining piping.

Component Testing and Numerical Calculation of a Bolted High Temperature Power Plant Pipe Flange Under Complex, Near-Service Loads

Abstract To ensure a reliable power supply with a minimum environmental impact in the future, further increases in efficiency and flexibility of fossil-fired power plants are major challenges to address in recent R&D activities. In order to counterbalance substantial fluctuations in the electricity grid due to the rising share of renewable resources, frequent start-ups and shut-downs of turbomachinery will be claimed by the market. Hence, along with the development of advanced materials for elevated steam parameters, contemplations with respect to altered boundary conditions of established materials, e.g., for bolted pipe flange connections, are required. In this paper, a selection of results from a recently finished research work on stress relaxation will be presented. Together with European power plant component manufacturers, a newly developed test rig comprising a scaled intermediate pressure (IP) steam turbine pipe flange now allows investigations under near-service conditions. Before, throughout, and after performance of the experiments, an extensive measurement setup enables the examination of effects that cannot be studied in standardized relaxation tests. Within this work, a loss in bolt pretension of up to almost 50% over a comparatively short period of experimental time was observed. By means of numerical calculations, creep deformation in the transition areas between pipe and flange plate sections was identified to be a major originator of these pretension drops. Particularly, good correlations between experiments and finite element method (FEM) simulations could be achieved through the implementation of enhancements concerning the fitting strategy of the Graham–Walles-type creep model which was used.

A Study of New Tightening Procedure for Bolted Pipe Flange Connections with Metallic Gaskets

A Study of New Tightening Procedure for Bolted Pipe Flange Connections with Metallic Gaskets

A Simple Method of the Load Factor Using a Circular Plate Theory for Bolted Pipe Flange Connections with Gaskets under Internal Pressure

A Simple Method of the Load Factor Using a Circular Plate Theory for Bolted Pipe Flange Connections with Gaskets under Internal Pressure

Evaluation of Mechanical Characteristics of Bolted Pipe Flange Connections with PTFE Blended Gaskets Subjected to External Bending Moments

Evaluation of Mechanical Characteristics of Bolted Pipe Flange Connections with PTFE Blended Gaskets Subjected to External Bending Moments

A Simple Method of the Load Factor and Design Based on an Allowable Leak Rate for Bolted Pipe Flange Connections with Gaskets under Internal Pressure

A Simple Method of the Load Factor and Design Based on an Allowable Leak Rate for Bolted Pipe Flange Connections with Gaskets under Internal Pressure

内圧作用下における大口径管フランジ締結体のFEM応力解析及び密封性の評価

内圧作用下における大口径管フランジ締結体のFEM応力解析及び密封性の評価

651 許容漏えい量を考慮した内圧を受ける金属平型ガスケット付き管フランジ締結体のボルト初期締付け力決定法

651 許容漏えい量を考慮した内圧を受ける金属平型ガスケット付き管フランジ締結体のボルト初期締付け力決定法

659 内圧を受ける非石綿ガスケット付き管フランジ締結体の有限要素法応力解析と密封性能評価について

659 内圧を受ける非石綿ガスケット付き管フランジ締結体の有限要素法応力解析と密封性能評価について

Stress Analysis and the Sealing Performance Evaluation of Bolted Pipe Flange Connections with Non-asbestos Compressed Sheet Gasket under Internal Pressure

Stress Analysis and the Sealing Performance Evaluation of Bolted Pipe Flange Connections with Non-asbestos Compressed Sheet Gasket under Internal Pressure

Stress Analysis and the Sealing Performance Evaluation of Bolted Pipe Flange Connections with Non-asbestos Spiral Wound Gasket under Internal Pressure

Stress Analysis and the Sealing Performance Evaluation of Bolted Pipe Flange Connections with Non-asbestos Spiral Wound Gasket under Internal Pressure

605 石綿規制に対する管フランジ締結体の設計と国際動向(フランジガスケット締結体の力学と密封性能評価II)

605 石綿規制に対する管フランジ締結体の設計と国際動向(フランジガスケット締結体の力学と密封性能評価II)

New Development in Studies on the Characteristics of Bolted Pipe Flange Connections in JPVRC

This paper deals with some studies carried out in the bolted flanged connection committee (BFC) in Japan Pressure Vessel Council (JPVRC) on the stress analysis of a pipe flange connection using the elastoplastic finite element method. The characteristics of the connections with the different nominal diameters from 2in. to 20in. such as the contact gasket stress distribution, the hub stress, and the load factors were examined. The results from the finite element analyses were fairly consistent with the experimental results concerning the variation in the axial bolt force. By using the contact stress distributions and the results of the leakage test, the new gasket constants were evaluated. As a result, it was found that the variations in the contact stress distributions were substantial due to the flange rotation in the pipe flange connections with the larger nominal diameter. A method to determine the bolt preload for a given tightness parameter was demonstrated and the difference in the bolt preload between our research and PVRC was shown. In addition, the characteristics of pipe flange connection under a bending moment and internal pressure were also discussed and a newly developed bolt tightening method was demonstrated.