Flange Type Research Articles

Use of Centrifugal Electroslag Casting for Producing Cold-Resistant Steel Grade Ring Blanks of Flange Objects

A method is considered for preparing objects of the flange type made of steel of grades 09G2S and 10G2 by centrifugal electroslag casting (CESC). Results are given for chemical analysis and mechanical properties of objects prepared by different methods. The advantage of CESC technology is demonstrated making it possible to prepare cast blanks that with respect to production parameters and physicomechanical properties correspond to the GOST and TU for the given forms of steel having configuration and dimensions close to a finished object.

Experimental Study of Inner-and-Outer Steel Flanges Subjected to Tension and Bending Loads

Inner-and-outer steel flange has gained many attentions in China. This type flange has both inner and outer rings, as well as bolts. To gain insight into the intrinsic characteristics of the flange, an experimental study is conducted, taking into account that the tension and bending loads are imposed simultaneously. The varying of relative displacement between two adjacent flange planes with external loading is surveyed. It is indicated that the deformation is almost linearly increased with the external loads, if there is no yielded bolt. Strain gauges are employed to capture the strain distribution in the ribs as well as the tube. The internal tension force of bolt is also measured in the test. It is revealed that the failure mode of the flange is the breaking of the outer bolts. Moreover, the existence of the tension load would reduce the bending bearing capacity of the flange, and prying force could be ignored. It is concluded that the plane-section assumption holds approximately. Accordingly, formulas are given to compute the bearing capacity of the flange. It is found that the computing method is quite conservative if the position of rotation axis takes a value of 0.8 times of the diameter of the steel tube.

Comparison of permeation of atmospheric gases through Viton O-ring gaskets for different initial conditions

Viton O-ring gaskets are frequently used in high vacuum for demountable flange and vacuum valve seals. Atmospheric gases, particularly water vapor from humid air, permeate through Viton gaskets and thus limit the lowest attainable pressure level in vacuum systems. In this work, a comparison of a vacuum degassed Viton O-ring gasket and a gasket fully saturated with atmospheric gases was performed. A reference measurement with an alternative soft metal gasket for Klein Flange type flanges was also made. The permeation rate of each individual gas from the atmosphere (water vapor, N2, O2, Ar, and CO2) through the Viton O-ring was measured using quadrupole mass spectrometry. The partial gas flow curves Q(t) were also modeled using finite difference modeling (FDM). Using FDM, one can determine the diffusion constant, permeability, and solubility of the gas in the material.

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

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.

Mechanical analyses of the waveguide flange coupling for the first confinement system of the ITER electron cyclotron upper launcher

The four electron cyclotron (EC) upper port antennas (or “upper launchers” —UL) will be used to drive current locally inside magnetic islands located at the q=2 (or smaller) rational surfaces in order to stabilize neoclassical tearing modes (NTMs), as well as heat inside of ρ of about 0.4. Each antenna consists of eight beam lines that are designed for the transmission of 1.5 MW of mm-wave power at 170GHz. The First Confinement System (FCS) is formed by the ex-vessel mm-wave waveguide components, for which SIC-1 classification requirements apply.The beam lines in the FCS comprise a Z shaped set of straight corrugated waveguides with a nominal diameter of 50mm connected by miter bends. This system is subjected to imposed displacements coming mainly from the thermal expansion of the vacuum vessel, seismic events and/or plasma disruption events. In absence of suitable SIC-1 waveguide bellows, the FCS waveguides must provide the necessary mechanical functional compliance. This has required the development of a dedicated, flange type coupling system with double metallic seals, capable of resisting the generated external loads while maintaining vacuum tightness and alignment. This paper presents the results of the design, analysis and pre-qualification experimental work done on the waveguides and the integrated SIC-1 compliant coupling system.

Propagation of thermally induced oscillation in the KSTAR cryogenic loop

Thermo-acoustic oscillation is well-known phenomena which can generate quite a heat load to a cryogenic system. Here we report that thermally induced oscillation has been occurred in the KSTAR cryogenic system and furthermore that oscillation propagates the cryogenic circuit, affects strongly the overall supercritical helium flow and generates severe mechanical vibration on the system. Additional vibration sensors were attached on the cryogenic circuit to trace the origin of that abrupt thermal leak and detailed hydraulic data analyses have been carried out. It was found that test heaters of flange type inserted in directly the by-pass lines are the origin of the thermally induced unexpected oscillation and thereby by the dismantle of the heaters the oscillation can be permanently eradicated.

Design of High Frequency Ultrasonic Transducers with Flexure Decoupling Flanges for Thermosonic Bonding

This paper presents the design of high-frequency ultrasonic transducers for micro/nano device thermosonic bonding. The transducers are actuated by piezoelectric ceramics and decoupled with their connecting parts through novel flexure decoupling flanges. First, the initial geometric dimensions of the transducers were calculated using electromechanical equivalent method, then dynamic optimization design was carried out based on three-dimensional (3-D) finite element method (FEM), and the geometric dimensions of the transducer were finally determined. Flexure decoupling flanges were presented, and the decoupling principle of the flanges was explained through compliance modeling using compliance matrix method and FEM. After that the dynamic characteristics of the transducers were analyzed through finite element analysis (FEA). The vibration frequencies and modes of the piezoelectric converter, concentrators, and transducers were obtained through modal analysis, and the displacement nodes were determined. The longitudinal ultrasonic energy transmission was presented, and the decoupling effects of the flexure flanges were compared. Finally, the transducers were manufactured and experimental tests were conducted to examine the transducer characteristics using an impedance analyzer. The experimental results match well with the FEA. The results show that the longitudinal vibration frequencies of the transducers with ring, prismatic beam, and circular notched hinge-based flanges are 126.6, 125.8, and 125.52 kHz, respectively. The decoupling flange with circular notched hinges shows the best decoupling effect among the three types of flanges.

S1720105 劣化を検知するセンシングシステムを埋設したFRP製貯槽のメンテナンス手法に対する一考察([S172]プロセスセイフティマネージメント,産業・化学機械と安全部門)

To evaluate the degradation of FRP storage tank in chemical plant, embedded optical fiber type sensing systems were studied about maintenance method matching with situation of setting the equipment. When it can be installed in opportunity of new construction of a FRP, it can be easily embedded in the FRP plate. When new FRP tank is supplied without embedding the sensor, blind flange type sensor with same resin system is convenient to install the monitoring system. For the old one already started to work, blind flange embedded tow or more sensors in it can monitor the penetration rate may be effective to evaluate the remaining life and decision of how to maintenance the FRP chemical storage equipment.

Novel Pile-to-Pilecap Connection Under Lateral Load

Pile-to-pilecap connection such as in integral abutment bridges is vulnerable to lateral loads as well as seismic loads. This connection may govern the bridge strength and performance against various lateral loads. However, previous researches have merely focused on the connection between pile and pilecap. Preliminary study has investigated possible crack patterns between concrete pilecap and steel HP pile using finite element analyses. It was found that the crack patterns are sensitive to the boundary conditions specified in the simulation. The reinforcement detail specified in PennDOT DM4 was barely effective in controlling crack growing but spiral rebar was proved to be effective in delaying crack growth as well as absorbing energy capacity. In this study, two types of connection details of (1) HSS tube type and (2) removed flange type were investigated in terms of crack control. The connection with a HSS tube exhibited to be effective in prevention of crack propagations from the surface of the bottom pilecap. However, second crack was initiated from the corner region of the tube after first crack was arrested; resulting in lower energy absorption capacity compared to both spiral and removed flange details. In the connection with removed flange, concrete crack initiations were mitigated or delayed successfully.

Shear strength of tubular flange plate girders with square web openings

In this paper, the influence of square opening sizes on the shear behavior of hollow tubular flange plate girders (HTFPGs) is investigated. A three-dimensional finite element (FE) modelling using the ABAQUS computer package has been employed to analyze HTFPGs containing central web openings at end panels. The results of the HTFPGs with web openings are analyzed and then compared with equivalent plate girders (IPGs) with such openings. The collapse behavior of such girders is examined considering the following parameters: the flange type; the flange size; the type of the web (solid web or web with opening); the web plate slenderness (hw/tw) and the relative opening depth to the web depth (do/hw). The results indicate that employing the HTFPGs with unreinforced central web opening without curved corners instead of the corresponding IPGs with the similar weight and the web opening size is a high performance solution to avoid the reduction in shear resistance due to the presence of web openings. An optimum web opening depth (do,op) for a HTFPG with a slender web is additionally recommended at which its shear strength becomes higher than the corresponding value of the similar weight IPG with solid web. It is furthermore found that the design strength of such girders should consider the sum of the contributions of both the web and the tubular flanges. However, new conclusions on the shear strength and behaviour of HTFPGs with web openings are presented.

Modeling and Validation of the Nonlinear Dynamic Behavior of Bolted Flange Joints

Linear dynamic finite element analysis can be considered very reliable today for the design of aircraft engine components. Unfortunately, when these individual components are built into assemblies, the level of confidence in the results is reduced since the joints in the real structure introduce nonlinearity that cannot be reproduced with a linear model. Certain types of nonlinear joints in an aircraft engine, such as underplatform dampers and blade roots, have been investigated in great detail in the past, and their design and impact on the dynamic response of the engine is now well understood. With this increased confidence in the nonlinear analysis, the focus of research now moves towards other joint types of the engine that must be included in an analysis to allow an accurate prediction of the engine behavior. One such joint is the bolted flange, which is present in many forms on an aircraft engine. Its main use is the connection of different casing components to provide the structural support and gas tightness to the engine. This flange type is known to have a strong influence on the dynamics of the engine carcase. A detailed understanding of the nonlinear mechanisms at the contact is required to generate reliable models and this has been achieved through a combination of an existing nonlinear analysis capability and an experimental technique to accurately measure the nonlinear damping behavior of the flange. Initial results showed that the model could reproduce the correct characteristics of flange behavior, but the quantitative comparison was poor. From further experimental and analytical investigations it was identified that the quality of the flange model is critically dependent on two aspects: the steady stress/load distribution across the joint and the number and distribution of nonlinear elements. An improved modeling approach was developed that led to a good correlation with the experimental results and a good understanding of the underlying nonlinear mechanisms at the flange interface.

Distortion and its Control in Welding of Stainless Steel Structures - Case Studies

Distortion is a perennial problem faced by engineers engaged in welding fabrication. The shape change deformations and change in the dimensions that occur after welding is termed as distortion, leading to various undesirable consequences. So there exists a necessity to control distortion within limits. When distortion exceeds acceptable limits, correction of distortion after the complete fabrication results in major reworking operation that consumes both fabrication time and cost. Distortion control in complex structures has always been a challenge to fabrication engineers, dealing with stainless steels. To arrive at an appropriate control method, an in-depth analysis of the shape change deformation behavior of the component and adaptation of appropriate methods to control distortion are essential. In this study, two circular components made of stainless steel have been taken up for control of distortion. The first structure is the labyrinth used in hydro turbine assembly that consists of a ring type of flange made of martensitic stainless steel (ASTM grade A240 S41500) welded with a shell type web using grooved fillet welds. The size of the welded assembly is huge and the quantum of weld is very high leading to heavy distortion that often required to be corrected by way of weld build-up and subsequent machining. The second one is the vortex finder assembly which is a part of cyclone separator that is used to separate the fine particles of coal from coarse ones for use in the combustion chamber of typical Circulating Fluidised Bed Combustion (CFBC) boilers. This is again a cylindrical structure with three shells joined with three flanges and supported by stiffeners. The structure is made of special grade Austenitic stainless steel to withstand high temperature. In both the structures, most of joints are of Tee-joints with fillet welds. During fabrication of these assemblies, the angular tilt, local waviness and the diameter variation were the major issues. Correction after fabrication is not viable considering the configuration and shape of the component. This calls for control of distortion during fabrication itself. Towards this, a suitable welding procedure using an appropriate weld sequence was evolved after studying the weld details of the components. This weld sequence was implemented in-situ in actual components. During fabrication on-line monitoring was carried out and course corrections were provided. After implementation of the weld sequence, it was found that the distortion of the component could be reduced and contained well within the permissible limits. This made the extra rework redundant thus leading to a significant reduction in the cycle time of manufacture of the component. The details of the methodology adopted are described in this paper. Keywords: Labyrinth assembly, vortex finder assembly, stainless steel welding, distortion, T joint, grooved fillet weld, angular tilt, weld sequence.

Damage inspection of the first mercury target vessel of JSNS

The liquid mercury target system for the Japan Spallation Neutron Source (JSNS) began operating in May 2008. A mercury target vessel composed of type 316L stainless steel suffers radiation damage in the proton and neutron environment. In addition to this damage, the inner wall of the target vessel in contact with mercury is damaged by cavitation-induced erosion, which is caused by rarefied pressure waves. The target vessel was replaced with a new target in November 2011, because the pneumatic bellow type flange was damaged during the Great East Japan Earthquake, that occurred on March 11, 2011. Before replacing the target, 50mm diameter disk specimens were cut from the beam window of the target vessel in order to investigate the cavitation damage inside the target vessel and to evaluate the change in the mechanical properties due to radiation damage. A video camera was used to inspect the inside of the target vessel and no flow induced erosion damage was detected on the flow guide by visual inspection. Cavitation damage from the proton pulse was concentrated at the center and approximately 15mm from the center of the beam window. In addition, the depth of the cavitation damage was quantitatively measured using a laser profilometer and a metallurgical surface replica. Based on the detailed measurements, it was concluded that the eroded damage depth of the beam window was 250μm after 475MWh of operation.

Cyclic Testing of Welded Free Flange Type and Welded Flange Plate Type Weak-Axis Steel Moment Connections

Moment resisting frames are most frequently used in seismic design systems for steel buildings. Following the Northridge and Kobe earthquakes there have been many studies examining the strong axis steel moment connections. In particular, these efforts have been supported by the government in the US. In Korea on the other hand, researches on the seismic behaviours of weak-axis moment connections are difficult to fine even though these connection details have been frequently used as seismic details of local MRF. As a result, the objective of this research is to provide information on the seismic behaviours of welded free flange type(FF) and welded flange plate type(WFP) weak-axis steel moment connections that were quoted by the FEMA. For this purpose, an experimental program was designed and performed with 2 types of weak-axis steel moment connections. From the test results, both FF and WFP type connections revealed to have more than 3% story drift capacity, which satisfy the required performance for OMF systems.

What is the preferred shape for an esophageal stent flange?

Self-expandable metallic stents (SEMS) for the gastrointestinal tract have different types of flanges at either the oral end or both ends to prevent stent migration. The effect of flange shape on the properties of SEMS, to our knowledge, has not been evaluated. The aim of this study was to measure the strain that a SEMS imposes on the adjacent wall and the anti-migration force (AF) exerted by three stents, each with a different flange shape. Stents with one of three different flanges (flared, dumbbell, and barrel) were designed and then their strain and AF values were measured with apparatuses devised in our laboratory. Although the average maximal strain values at the flange were similar (508.4 µm/m, 513.3 µm/m and 486.4 µm/m for flared, dumbbell and barrel, respectively), strain values for each position differed among the three different types of stents. Strain values for the flared shape increased toward the stent end, reaching the maximum value. Maximal strain values for the dumbbell and barrel shapes were observed near the flange's midpoint. Maximal AF values differed significantly according to flange shape. Thus, the median maximal AF values were 1.85 newton, 1.35 newton, and 1.13 newton, for barrel, dumbbell and flared shapes, respectively. The performance of braided esophageal SEMS with barrel shaped flanges is superior to that of SEMS with dumbbell or flared flanges, based on the strain on the adjacent wall and the prevention of stent migration.

Contrast observation and investigation of wheat endosperm transfer cells and nucellar projection transfer cells

In cereal seed, there are no symplastic connections between the maternal tissues and the endosperm. In order to facilitate solute transport, both the nucellar projection and its opposite endosperm epithelial cells in wheat caryopsis differentiate into transfer cells. In this paper, we did contrast observation and investigation of wheat endosperm transfer cells (ETC) and nucellar projection transfer cells (NPTC). The experimental results showed that there were some similarities and differences between ETC and NPTC. ETC and NPTC almost developed synchronously. Wall ingrowths of ETC and NPTC formed firstly in the first layer nearest to the endosperm cavity, and formed later in the inner layer further from the endosperm cavity. The mature ETC were mainly three layers and the mature NPTC were mainly four layers. Wall ingrowths of ETC were flange type and wall ingrowths of NPTC were reticulate type. NPTC were not nutrient-storing cells, but the first layer of ETC had aleurone cell features, and the second layer and third layer of ETC accumulated starch granules and protein bodies.

Influence of insulating spacer type on propagation properties of PD-induced electromagnetic wave in GIS

The authors have studied insulation diagnostic technique of gas-insulated switchgear (GIS) by UHF (ultra high frequency) method. In this paper, the authors investigated the effect of insulating spacer type (metal flange type (MT) or bush type (BT)) on the propagation properties of partial discharge (PD) induced electromagnetic (EM) wave in GIS with UHF method. Low pass filtering process for cutoff frequency of TE11 mode was used to eliminate the higher order mode above TE11 of detected signal. Results revealed that reduction of the magnitude of measured EM waveform by passing through spacers. The reduction was found to be not due to attenuation by the spacer, but mainly due to superimposition of reduced TE mode and TEM mode. Furthermore, the authors investigated relationship between the propagating EM wave in GIS and a leaked EM wave from a BT spacer. This result suggests that insulation diagnosis by a sensor placed outside of GIS could be carried out to detect the leaked EM wave through a BT spacer.

Finite Element Analysis of Behavior of Bolted Flange Connections under Bending Loading

Only a limited number of experimental and analysis reports exist concerning bolted flange connections under bending loading. In order to investigate the complex nonlinear phenomena, three dimensional elasto-plastic finite element analyses are performed. In those analyses, frictional contact model with small sliding option is applied between contacting pair surfaces of all connecting elements. Bolt pretension force is introduced in the initial step of analysis. From this study, the following results are obtainted:1) proposed finite element analysis method can be applicable to estimate complex nonlinear behavior of bolted flange type connections; 2) There is a sharp change in bending stiffness during loading, and lateral slip between two jointed flanges cause the bolt to carry shear load. The design of bolted joints should consider the interaction among cylinders, flanges and bolts.

Application of MO-Type Flange for Accelerator Beam Ducts 3

Based on experiences in the precedent stain-less steel case, a possibility of employing copper-alloy and aluminum-alloy Matsumoto-Ohtsuka (MO)-type flanges in a vacuum beam pipes for a particle accelerator is experimentally studied. They can mitigate the heating problems found in the case of stainless-steel flanges under high-intensity beams, and also simplify the manufacturing procedure of beam pipes. Copper-alloy flanges show a comparable vacuum sealing property to the stainless-steel one, and several beam pipes with the copper-alloy flange has been successfully installed in the KEKB B-factory positron ring. The R&D on aluminum-alloy flanges has just started, and a promising result is obtained. Any coatings or treatments to improve the hardness of sealing part can be omitted if duralumin-series aluminum alloys are used. However, further detailed investigations are required about the hardness and stiffness properties of the gasket and flange materials before applying the flanges to the real machine.

A Robust Installation for Brick-Mold Windows and Doors Using Self-Adhered Flashing

Abstract Current standardized practices for window and door installation methodologies are typically based on fenestration products that feature integral flanges that form a continuous surface to mount and integrate the fenestration product to the water resistive barrier (WRB)/drainage plane of the wall. While these types of units form the majority of fenestration products available, there are several “non-integral” flange type systems that are also utilized in the construction industry. These include “brick-mold” windows and doors, field-applied flange windows, and non-flanged “box” windows. Due to the discontinuity between the mounting system and the window frame, these types of fenestration systems pose special challenges to achieve a robust, continuous, and water-resistant integration between the fenestration product and the wall, which is not adequately addressed by ASTM E2112, “Standard Practice for Installation of Exterior Windows, Doors, and Skylights” or other standardized methods. The paper describes an installation method for windows and doors with factory-applied brick-mold exterior casings and presents the performance characteristics in laboratory testing of units installed using the method.