Manufacturing of Bellows Compensator by Pulsed-Magnetic Field Pressure

Bellows are a cylindrical shell with a corrugated part, widely used in aviation engineering as a movable sealing element to balance pressure and temperature differences, which ensure continuous and accurate system operation. The use of bellows expansion joints provides reliable and effective protection of pipelines from static and dynamic loads arising from deformations and vibration. Welded-edge bellows are a popular choice for regulating and controlling fuel supply in aircraft devices. The ability of the compensator to perceive deformations is determined by its assigned operating time, which describes how many cycles, and with what amplitude, the bellows compensator perceives without damage. A method for stamping bellows from tubular billets by using magnetic-pulse field in rigid dies, including sequential shaping of corrugations by distributing the internal magnetic pressure with axial movement of the free end of a tubular billet, characterized in that the material of the tubular billet for shaping corrugations is selected in accordance with its relative elongation.

Additional forces on continuously welded rails of a long-span high-speed railway suspension bridge under single effect and multiple effects: A case study

This paper investigates the track–bridge interactions of the Wufengshan Yangtze Bridge, the longest high-speed railway suspension bridge in China. A finite element model of the track and bridge is built using the commercial software ANSYS. The longitudinal additional forces of the track under a single effect and combination effects of temperature rising load, bending load, and braking load are calculated. The numerical results show that strong additional forces appear in the continuously welded rail of the Wufengshan Yangtze Bridge. Temperature effect is the dominant factor for the residual internal forces. The maximum tensile stress is 115.5 MPa and the extreme compressive stress reaches 329.9 MPa. Rail expansion joints are needed for this long-span suspension bridge.

Evaluation and Load Rating of a Steel Girder In-Span Hinge Connection

Continuous steel plate girder bridges often use intermediate expansion joints located at in-span hinges to divide the superstructure into individual units with shorter expansion lengths. One common type of in-span hinge is often termed a “shiplap joint.” This type of joint is located away from piers near the moment inflection point of the span, maximizing girder efficiency. It consists of a cantilevered portion of the superstructure supporting a suspended portion of the latter on bearings placed on dapped portions of the steel plate girders. Few references are available for the evaluation and load rating of shiplap in-span hinges used in steel girder bridges. In this study, the strength and stability of a typical shiplap hinge connection is evaluated using two methodologies: a 3D finite element model including a detailed mesh of the connection; and a proposed simplified methodology based on design equations. Load ratings of the connections based on these methodologies are compared. The proposed approach allows for a conservative assessment of the hinge without the need for a detailed finite element model.

Investigations on Structural Integrity of Piping Compensators Under Angular Rotational Deformation

The aim of this paper is to investigate the effect of angular rotational misalignment in pipe structure on the deflection based convolution stresses. Such stresses are generated in the thin walled unreinforced bellows compensators during the expansion-contraction function. On the convolution geometry, the most vulnerable stress type is meridional deflection stresses under the internal pressure. Therefore, it’s critical to check the structural integrity of pipe systems with bellows expansion joints, which typically connected to the process equipment’s including boilers, pressure vessels, reactors, heat exchangers, refineries, and so on. The findings of theoretical and experimental investigations of thin-walled unreinforced conditioned bellows subjected to different angular rotations are presented in this paper. The meridional deflection stresses are investigated for the different operating pressures when bellows subjected to angular rotations of 1°, 1.5° and 2° in the flexural plane. In addition, the testing is performed along various longitudinal lines across the periphery of the bellows to determine the maximum induced stress points on the convolution profile. The higher meridional stress is seen to be the bending stress at the bottom curved toroidal section of the convolution, which approaches towards the elastoplastic regime at 1° to 2° of angular deviation in flexural plane. These extreme stress points may prove the risky areas at the root of the convolution for the fatigue failures. Further, the results of the maximal convolution stress assessment are useful in predicting the structural integrity of bellows in elastic regime, when prone to the angular shift.

Performance analysis and material selection of stainless steel expansion joints for power grid equipment

Stainless steel expansion joint, as the connecting part of GIS equipment, has the function of compensating the deformation of GIS caused by cold and hot stress. And it should at least meet the requirements of anti-corrosion and non-magnetic according to the working environment. This work investigate the performance of 304, 316L and 825 austenitic stainless steel expansion joints by metallographic analysis, hardness test, XRD analysis and magnetic analysis, and suggestions on material selection of expansion joint for power grid equipment are put forward.

Flexural Behavior of Polyurethane Concrete Reinforced by Carbon Fiber Grid

In view of the problems of traditional repair materials for anchorage concrete of expansion joints, such as ease of damage and long maintenance cycles, the design of polyurethane concrete was optimized in this article, which could be used for rapid repair of concrete in anchorage zone of expansion joints. A new type of carbon fiber grid–polyurethane concrete system was designed, which makes the carbon fiber grid have an excellent synergistic effect with the quick-hardening and high-strength polyurethane concrete, and improved the flexural bearing capacity of the polyurethane concrete. Through the four-point bending test, the influence of the parameters such as the number of grid layers, grid width, and grid density on the flexural bearing capacity of polyurethane concrete beams was tested. The optimum preparation process parameters of carbon fiber grid were obtained to improve the flexural performance of polyurethane concrete. Compared with the Normal specimen, C-80-1’s average flexural strength increased by 47.7%, the failure strain along the beam height increased by 431.1%, and the failure strain at the bottom of the beam increased by 68.9%. The best width of the carbon fiber grid was 80 mm, and the best number of reinforcement layers was one layer. The test results show that the carbon fiber grid could improve the flexural bearing capacity of polyurethane concrete. The carbon fiber grid–polyurethane concrete system provides a new idea for rapid repair of the anchorage zone of bridge expansion joints, and solves the problems such as ease of damage and long maintenance cycles of traditional repair materials, which can be widely used in the future.

Process Piping: The Complete Guide to ASME B31.3, Fourth Edition

Fully updated for the 2020 Edition of the ASME B31.3 Code, this fourth edition provides background information, historical perspective, and expert commentary on the ASME B31.3 Code requirements for process piping design and construction. It provides the most complete coverage of the Code that is available today and is packed with additional information useful to those responsible for the design and mechanical integrity of process piping. The author and the primary contributor to the fourth edition, Don Frikken are a long-serving members, and Prior Chairmen, of the ASME B31.3, Process Piping Code committee. Dr. Becht explains the principal intentions of the Code, covering the content of each of the Code's chapters. Book inserts cover special topics such as calculation of refractory lined pipe wall temperature, spring design, design for vibration, welding processes, bonding processes and expansion joint pressure thrust. Appendices in the book include useful information for pressure design and flexibility analysis as well as guidelines for computer flexibility analysis and design of piping systems with expansion joints. From the new designer wanting to known how to size a pipe wall thickness or design a spring to the expert piping engineer wanting to understand some nuance or intent of the code, everyone whose career involves process piping will find this to be a valuable reference.