Evaluation of the Structural Integrity of Bell-Spigot Joints in Steel Gas Pipelines

2021 ◽  
Author(s):  
Freddy Alvarez ◽  
Heriberto Maury ◽  
Jorge Bris ◽  
Ricardo Lizarazo ◽  
Julio A. Medina S. ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Operating Conditions ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Test Pieces ◽  
Pull Out ◽  
Design Variables ◽  
Natural Gas Transmission ◽  
Transmission Pipeline ◽  
Operation Pressure

Abstract The most common joining method in steel gas pipelines is welding; however, this method involves time-consuming, expensive manufacturing and assembly processes to ensure quality in operation. Bell-Spigot joints, which work by mechanical interference, have started to be used as an alternative joining method in steel pipes. Its use has increased due to its reduced assembly time and less post-assembly inspection requirements. In this paper, the structural performance of Bell-Spigot joints in 16-inch steel pipe API 5L X70 with Fusion Bonded Epoxy (FBE) coating for Natural Gas transmission pipeline are evaluated experimentally and by modeling. Test pieces were taken from the gas pipeline after 3 years of operation. Then, tensile pull-out and bending with hydrostatic pressure tests were performed to replicate operating conditions. Deformations, displacements, and the potential presence of leaks were monitored. Experimental results were compared with a Finite Element Method model. Finally, an analytical model for the calculation of stresses and strains in the joint system's components was developed. It was determined that the tightness of the joint depends mainly on the radial interference and the interference length. A higher safety factor can be obtained at the bell-spigot joint than the base pipeline by optimizing selection of joint design variables and the service loading conditions. If the interference pressure is lower than half of the operation pressure, the joint's mechanical strength will be higher or equal that the base pipe.

Economic Evaluation Technique of Selecting Turbines for Natural Gas Pipelines

1978 ◽  
Author(s):  
T. E. Hajnal
Keyword(s):  
Economic Evaluation ◽  
Natural Gas ◽  
Operating Costs ◽  
Evaluation Technique ◽  
Gas Pipelines ◽  
Natural Gas Pipelines ◽  
Pipeline Systems ◽  
Natural Gas Transmission ◽  
Transmission Pipeline ◽  
Type Size

Designers of natural gas transmission systems often have to make recommendations as to the type, size, and number of turbines to be purchased and installed either on new pipelines or on expanding existing systems. This paper describes the economic evaluation technique which is being used by TransCanada PipeLines, of selecting turbines for natural gas transmission pipeline systems. The technique is based on comparing the present worths of annual owning and operating costs associated with the turbines considered for installation.

Effects of Defect Shapes on Stress of High-Strength Steel Pipe Using FSI Method

2014 ◽  
Vol 577 ◽  
pp. 154-157
Author(s):  
Yue Cui ◽  
Hui Qing Lan ◽  
Zhao Hui Zhang ◽  
Nan Lin ◽  
Yong Ping Du
Keyword(s):  
High Strength Steel ◽  
Failure Process ◽  
High Strength ◽  
Operating Conditions ◽  
Steel Pipe ◽  
Test Results ◽  
Element Analysis ◽  
Steel Pipes ◽  
Natural Gas Transmission ◽  
Fracture Arrest

High-strength steel pipes have excellent strength but have poor fracture arrest. By finite-element analysis involving fluid-structure interaction (FSI) method, models of high-strength steel pipe with three kinds of defects (triangle, rectangle and semi-ellipse) were built to determine the concentrated stress based on the working conditions of X70 pipelines in the West-to-East Natural Gas Transmission Project, and the simulation results were compared with the field test results measured by an X-ray stress analyzer. With the same defect width (2 mm), the triangular defect (40°) had a greater influence on the concentrated stress in the pipe than rectangular and semi-elliptic defects. The results can be taken as references of the damage failure process of the defect in pipes in operating conditions as well as a theoretical basis for the fracture arrest of pipes in field operation.

Morphing Airfoil Design via L-System Generated Topology Optimization

2019 ◽  
Author(s):  
Madalyn Mikkelsen ◽  
Michayal Mathew ◽  
Patrick Walgren ◽  
Brent Bielefeldt ◽  
Pedro B. C. Leal ◽  
...  
Keyword(s):  
Structural Integrity ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Structural Topology ◽  
High Lift ◽  
L System ◽  
Design Variables ◽  
Weakly Coupled ◽  
System L ◽  
Internal Configuration

Abstract Morphing airfoils present an effective approach to managing the different requirements in each segment of a mission profile (e.g., takeoff/landing, cruise, and active maneuvering). In this work, an approach to morphing airfoil design that couples aerodynamic performance and internal structural configuration is detailed. The internal structural topology is formulated using a Lindenmayer System (L-System) coupled with a graph-based interpreter known as Spatial Interpretation for Development of Reconfigurable Structures (SPIDRS). The L-System encodes design variables that are interpreted via SPIDRS graphical operations and governs the development of the internal configuration (composed of elastic structural members and actuators). The global optimization uses a weakly coupled fluid-structure interaction (FSI) scheme for a first-order estimation of the aeroelastic loads that are critical for airfoil aerodynamic performance and structural integrity. Each airfoil is evaluated in two states: a standard non-actuated state to determine performance in standard operating conditions (e.g., cruise) and a high lift state, where internal shape memory alloy actuators are deformed to create a high lift configuration for the airfoil (e.g., takeoff/landing). Evaluating the aerodynamic performance of airfoils in these two states results in a series of potential solutions that best manage the tradeoff between aerodynamic metrics for both evaluated cases.

Failure Analysis Of Buried Gas Pipelines Crossing Seismic Faults

2020 ◽  
Vol 3 (2) ◽  
pp. 781-790
Author(s):  
M. Rizwan Akram ◽  
Ali Yesilyurt ◽  
A.Can. Zulfikar ◽  
F. Göktepe
Keyword(s):  
Ground Deformation ◽  
Warning System ◽  
Strike Slip ◽  
Gas Pipelines ◽  
Steel Pipes ◽  
Seismic Fault ◽  
Fault Parameters ◽  
Dip Angle ◽  
Permanent Ground Deformation ◽  
Recent Earthquakes

Research on buried gas pipelines (BGPs) has taken an important consideration due to their failures in recent earthquakes. In permanent ground deformation (PGD) hazards, seismic faults are considered as one of the major causes of BGPs failure due to accumulation of impermissible tensile strains. In current research, four steel pipes such as X-42, X-52, X-60, and X-70 grades crossing through strike-slip, normal and reverse seismic faults have been investigated. Firstly, failure of BGPs due to change in soil-pipe parameters have been analyzed. Later, effects of seismic fault parameters such as change in dip angle and angle between pipe and fault plane are evaluated. Additionally, effects due to changing pipe class levels are also examined. The results of current study reveal that BGPs can resist until earthquake moment magnitude of 7.0 but fails above this limit under the assumed geotechnical properties of current study. In addition, strike-slip fault can trigger early damage in BGPs than normal and reverse faults. In the last stage, an early warning system is proposed based on the current procedure. 

scholarly journals Mode I Crack Propagation Experimental Analysis of Adhesive Bonded Joints Comprising Glass Fibre Composite Material under Impact and Constant Amplitude Fatigue Loading

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4380
Author(s):  
Alirio Andres Bautista Villamil ◽  
Juan Pablo Casas Rodriguez ◽  
Alicia Porras Holguin ◽  
Maribel Silva Barrera
Keyword(s):  
Crack Propagation ◽  
Structural Integrity ◽  
Crack Propagation Rate ◽  
Fatigue Loading ◽  
Propagation Rate ◽  
Operating Conditions ◽  
Impact Testing ◽  
Mode I ◽  
Mode I Crack ◽  
Constant Amplitude

The T-90 Calima is a low-wing monoplane aircraft. Its structure is mainly composed of different components of composite materials, which are mainly bonded by using adhesive joints of different thicknesses. The T-90 Calima is a trainer aircraft; thus, adverse operating conditions such as hard landings, which cause impact loads, may affect the structural integrity of aircrafts. As a result, in this study, the mode I crack propagation rate of a typical adhesive joint of the aircraft is estimated under impact and constant amplitude fatigue loading. To this end, effects of adhesive thickness on the mechanical performance of the joint under quasistatic loading conditions, impact and constant amplitude fatigue in double cantilever beam (DCB) specimens are experimentally investigated. Cyclic impact is induced using a drop-weight impact testing machine to obtain the crack propagation rate (da/dN) as a function of the maximum strain energy release rate (GImax) diagram; likewise, this diagram is also obtained under constant amplitude fatigue, and both diagrams are compared to determine the effect of each type of loading on the structural integrity of the joint. Results reveal that the crack propagation rate under impact fatigue is three orders of magnitude greater than that under constant amplitude fatigue.

Fully Parametric High-Fidelity CFD Model for the Design Optimisation of the Cyclic Stagger Pattern of a Set of Fan Outlet Guide Vanes

2009 ◽  
Author(s):  
Andrea Milli ◽  
Olivier Bron
Keyword(s):  
Complex Geometry ◽  
Single Point ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
High Fidelity ◽  
Cfd Model ◽  
Design Optimisation ◽  
Guide Vanes ◽  
High Loss ◽  
Design Variables

The present paper deals with the redesign of cyclic variation of a set of fan outlet guide vanes by means of high-fidelity full-annulus CFD. The necessity for the aerodynamic redesign originated from a change to the original project requirement, when the customer requested an increase in specific thrust above the original engine specification. The main objectives of this paper are: 1) make use of 3D CFD simulations to accurately model the flow field and identify high-loss regions; 2) elaborate an effective optimisation strategy using engineering judgement in order to define realistic objectives, constraints and design variables; 3) emphasise the importance of parametric geometry modelling and meshing for automatic design optimisation of complex turbomachinery configurations; 4) illustrate that the combination of advanced optimisation algorithms and aerodynamic expertise can lead to successful optimisations of complex turbomachinery components within practical time and costs constrains. The current design optimisation exercise was carried out using an in-house set of software tools to mesh, resolve, analyse and optimise turbomachinery components by means of Reynolds-averaged Navier-Stokes simulations. The original configuration was analysed using the 3D CFD model and thereafter assessed against experimental data and flow visualisations. The main objective of this phase was to acquire a deep insight of the aerodynamics and the loss mechanisms. This was important to appropriately limit the design scope and to drive the optimisation in the desirable direction with a limited number of design variables. A mesh sensitivity study was performed in order to minimise computational costs. Partially converged CFD solutions with restart and response surface models were used to speed up the optimisation loop. Finally, the single-point optimised circumferential stagger pattern was manually adjusted to increase the robustness of the design at other flight operating conditions. Overall, the optimisation resulted in a major loss reduction and increased operating range. Most important, it provided the project with an alternative and improved design within the time schedule requested and demonstrated that CFD tools can be used effectively not only for the analysis but also to provide new design solutions as a matter of routine even for very complex geometry configurations.

Improvement of the Static and Dynamic Characteristics of Magnetic Head Sliders by Optimum Design

1999 ◽  
Vol 122 (1) ◽  
pp. 280-287 ◽  
Author(s):  
Hiromu Hashimoto ◽  
Yasuhisa Hattori
Keyword(s):  
Objective Function ◽  
Optimum Design ◽  
Amplitude Ratio ◽  
Optimization Technique ◽  
Hard Disk Drives ◽  
Maximum Amplitude ◽  
Disk Surface ◽  
Operating Conditions ◽  
Magnetic Head ◽  
Design Variables

The aim of this paper is to develop a general methodology for the optimum design of magnetic head sliders in improving the spacing characteristics between a slider and disk surface under static and dynamic operating conditions of hard disk drives and to present an application of the methodology to the IBM 3380-type slider design. To generate the optimal design variables, the objective function is defined as the weighted sum of the minimum spacing, the maximum difference in the spacing due to variation of the radial location of the head, and the maximum amplitude ratio of the slider motion. Slider rail width, taper length, taper angle, suspension position, and preload are selected as the design variables. Before the optimization of the head, the effects of these five design variables on the objective function are examined by a parametric study, and then the optimum design variables are determined by applying the hybrid optimization technique, combining the direct search method and successive quadratic programming. From the obtained results, the effectiveness of optimum design on the spacing characteristics of magnetic heads is clarified. [S0742-4787(00)03701-2]

Evaluation of Fuel Preparation Systems for Lean Premixing-Prevaporizing Combustors

1986 ◽  
Vol 108 (2) ◽  
pp. 391-395
Author(s):  
W. J. Dodds ◽  
E. E. Ekstedt
Keyword(s):  
System Design ◽  
Large Scale ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Design Concepts ◽  
Mixture Preparation ◽  
Design Variables ◽  
System Length

A series of tests was conducted to provide data for the design of premixing-prevaporizing fuel-air mixture preparation systems for aircraft gas turbine engine combustors. Fifteen configurations of four different fuel-air mixture preparation system design concepts were evaluated to determine fuel-air mixture uniformity at the system exit over a range of conditions representative of cruise operation for a modern commercial turbofan engine. Operating conditions, including pressure, temperature, fuel-air ratio, and velocity had no clear effect on mixture uniformity in systems which used low-pressure fuel injectors. However, performance of systems using pressure atomizing fuel nozzles and large-scale mixing devices was shown to be sensitive to operating conditions. Variations in system design variables were also evaluated and correlated. Mixture uniformity improved with increased system length, pressure drop, and number of fuel injection points per unit area. A premixing system compatible with the combustor envelope of a typical combustion system and capable of providing mixture nonuniformity (standard deviation/mean) below 15% over a typical range of cruise operating conditions was demonstrated.

Pressure Test Planning to Prevent Internal Corrosion by Residual Fluids

2012 ◽  
Author(s):  
Trevor Place ◽  
Greg Sasaki ◽  
Colin Cathrea ◽  
Michael Holm
Keyword(s):  
Structural Integrity ◽  
Large Diameter ◽  
Long Distance ◽  
Internal Corrosion ◽  
Pressure Testing ◽  
Practical Strategy ◽  
Leak Testing ◽  
Pressure Test ◽  
Transmission Pipeline ◽  
Pipeline Project

Strength and leak testing (AKA ‘hydrotesting’, and ‘pressure testing’) of pipeline projects remains a primary method of providing quality assurance on new pipeline construction, and for validating structural integrity of the as-built pipeline [1][2][3]. A myriad of regulations surround these activities to ensure soundness of the pipeline, security of the environment during and after the pressure testing operation, as well as personnel safety during these activities. CAN/CSA Z662-11 now includes important clauses to ensure that the pipeline designer/builder/operator consider the potential corrosive impacts of the pressure test media [4]. This paper briefly discusses some of the standard approaches used in the pipeline industry to address internal corrosion caused by pressure test mediums — which often vary according to the scope of the pipeline project (small versus large diameter, short versus very long pipelines) — as well as the rationale behind these different approaches. Case studies are presented to highlight the importance of considering pressure test medium corrosiveness. A practical strategy addressing the needs of long-distance transmission pipeline operators, involving a post-hydrotest inhibitor rinse, is presented.

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