Evaluation of Girth Weld Defect Acceptance Criteria for Grade X100 Pipelines

2012 ◽  
Author(s):  
Troy Swankie ◽  
Vinod Chauhan ◽  
Ian Wood ◽  
Richard Espiner ◽  
Max Kieba ◽  
...  
Keyword(s):  
Analytical Methods ◽  
Large Scale ◽  
Charpy Impact ◽  
Assessment Methods ◽  
Test Facility ◽  
Weld Defect ◽  
Girth Welds ◽  
Assessment Procedures ◽  
Large Scale Tests ◽  
Pipeline Design

There are a number of methods that are commonly used for the assessment of a girth weld containing a ‘fabrication’ defect. These range from the more generic workmanship limits through to more complex pipeline specific Engineering Critical Assessment (ECA) methodologies. The workmanship limits stipulated in pipeline design codes can be very conservative, resulting in un-necessary and costly repairs. The ECA approach is being increasingly used to derive girth weld defect acceptance limits specific to a pipeline. These limits have been derived using either semi-analytical methods or from the results of large-scale tests conducted on pipeline girth welds. However, at present there is no one standardized method. The guidance produced by the European Pipeline Research Group (EPRG) is an example of an established methodology based on the results of large-scale tests, while commonly used pipeline specific semi-analytical assessment methods include API 1104 and CSA Z662. Other commonly used analytical methods, which are more generic in application, include BS 7910 and API 579-1/ASME FFS-1. Application of these methods to girth welds in grade X100 pipelines has not yet been validated. The US Department of Transportation, Pipeline and Hazardous Materials Safety Administration (PHMSA) commissioned Electricore, Inc and GL Noble Denton to investigate the applicability of these ‘commonly used’ girth weld assessment procedures to grade X100 pipelines. To facilitate this project, BP provided 10 girth welds from a full-scale operational trial of two grade X100 48in diameter pipeline test sections, following completion of the trial at GL Noble Denton’s Spadeadam test facility, Cumbria, UK. The girth welds were selected to enable the effects of material variability between abutting pipes, different heats and different manufacturers (pipe was sourced from two world class pipe mills, with the plate supply for one mill coming from two sources) to be investigated. A substantial test program has been undertaken to fully characterize the mechanical properties of each girth weld, comprising curved wide plate (CWP), tensile, Charpy impact and fracture mechanics tests. The results from the CWP tests have been analyzed using the procedures given in API 1104 (Option 2), EPRG, CSA Z662, BS 7910 and API 579-1/ASME FFS-1. This paper presents an overview of the tests undertaken and a comparison of the actual test results with the predictions from the assessment methods.

Pressure Correction Factor for Strain Capacity Predictions Based on Curved Wide Plate Testing

2012 ◽  
Author(s):  
Matthias Verstraete ◽  
Wim De Waele ◽  
Rudi Denys ◽  
Stijn Hertelé
Keyword(s):  
Correction Factor ◽  
Large Scale ◽  
Strain Capacity ◽  
Defect Assessment ◽  
Ductile Crack Growth ◽  
Large Scale Testing ◽  
Weld Defect ◽  
Girth Welds ◽  
Assessment Procedures ◽  
Tensile Strain Capacity

Strain-based girth weld defect assessment procedures are essentially based on large scale testing. Ever since the 1980’s curved wide plate testing has been widely applied to determine the tensile strain capacity of flawed girth welds. However, the effect of internal pressure is not captured in curved wide plate testing. Accordingly, unconservative predictions of strain capacity occur when straightforwardly transferred to pressurized pipes. To address this anomaly, this paper presents results of finite element simulations incorporating ductile crack growth. Simulations on homogeneous and girth welded specimens indicate that a correction factor of 0.5 allows to conservatively predict the strain capacity of a pressurized pipe through wide plate testing under the considered conditions.

Application of State of the Art Assessment for Pipeline Girth Weld

2017 ◽  
Vol 898 ◽  
pp. 1063-1068
Author(s):  
Deng Zun Yao ◽  
Zhi Wen Li ◽  
Jian Wu Liu ◽  
Lin Chen
Keyword(s):  
State Of The Art ◽  
Axial Stress ◽  
Construction Cost ◽  
Assessment Methods ◽  
Weld Repair ◽  
Defect Assessment ◽  
Weld Defect ◽  
Key Points ◽  
Welding Defects ◽  
Girth Welds

In the pipeline construction, the girth welds tend to be the weakness because of defects and microstructural heterogeneities. The importance of suitable assessment of various defects in the weld is not only to prevent the cracks from unstable growth to cause catastrophic accident but also can effectively reduce the weld repair to reduce construction cost. Although many welding defects assessment methods and codes have been applied in this field, there are many differences among them. In this paper, the application of weld defect assessment methods was extensively studied. The key points of ECA applications, such as the pipeline axial stress and toughness, have been introduced. Furthermore, some suggestions were given on the application of girth weld ECA assessment.

Controlled Large-Scale Tests of Practical Grounding Electrodes—Part I: Test Facility and Measurement of Site Parameters

2014 ◽  
Vol 29 (3) ◽  
pp. 1231-1239 ◽  
Author(s):  
D. Guo ◽  
D. Clark ◽  
D. Lathi ◽  
N. Harid ◽  
H. Griffiths ◽  
...  
Keyword(s):  
Large Scale ◽  
Test Facility ◽  
Large Scale Tests

Effect of Pipe and Weld Metal Post-Yield Characteristics on Plastic Straining Capacity of Axially Loaded Pipelines

2004 ◽  
Author(s):  
Rudi Denys ◽  
Wim De Waele ◽  
Anton Lefevre
Keyword(s):  
Mechanical Properties ◽  
Weld Metal ◽  
Large Scale ◽  
Important Variable ◽  
Plastic Strains ◽  
Deformation Characteristics ◽  
Girth Welds ◽  
Critical Regions ◽  
Large Scale Tests ◽  
Metal Post

Girth welds in pipelines subject to longitudinal plastic tensile strains are critical regions of the pipeline. As girth welds might contain flaws of some form or other, it is of paramount interest to have a thorough understanding of the deformation characteristics of girth welds in the post-yield loading range. The response of a defective weld to plastic strains depends on many variables. While toughness is an important variable, large-scale tests demonstrate that the plastic straining capacity is directly affected by the mechanical properties of the materials surrounding the defect. The purpose of this paper is to describe the effect of the interrelation between the pipe and weld metal post-yield characteristics on the straining capacity of girth welds containing a defect.

ATLAS PLUS: Design of Large Scale Fracture Mechanics Tests on a Ferritic Pipe

2018 ◽  
Author(s):  
Tomas Nicak ◽  
Tobias Bolinder ◽  
Elisabeth Keim ◽  
Alexander Eriksson ◽  
Patrick Le Delliou ◽  
...  
Keyword(s):  
Fracture Mechanics ◽  
Large Scale ◽  
Crack Tip ◽  
Bending Test ◽  
Test Facility ◽  
Small Scale ◽  
Integrity Assessment ◽  
Design Calculations ◽  
Crack Tip Constraint ◽  
Large Scale Tests

This paper summarizes the design calculations performed by Framatome, EDF, KIWA INSPECTA and VTT for three large scale tests on ferritic pipes made of material WB 36 (15 NiCuMoNb 5). The large scale tests will be performed on a 4-point bending test facility provided by EDF under displacement control at room temperature. The overall goal of the planned large scale tests is to demonstrate the effect of the crack tip constraint on the fracture toughness at the component level. Results of those tests will be utilized to develop and validate advanced tools for structural integrity assessment within WP 3 particularly with respect to the transferability of material properties from small scale specimens to large scale components as well as for the development and validation of a procedure for the determination of component fracture resistance curves. Three configurations of the initial defect with different constraint conditions (one through-wall and two surface cracks) are considered. The design calculations are divided into two parts. In the first part an optimization of three different crack shapes is performed on basis of the standard fracture mechanics approach (based on J-Integral) without consideration of the constraint effect. In the second part a quantification of the crack tip constraint for the selected crack configurations from part I is performed. The effect of the constraint on the crack initiation and propagation for the selected crack configurations shall be assessed and compared between each other. Based on these calculations the final flaw configuration for each large scale experiment is selected.

scholarly journals A Full-Scale Investigation Into Pipeline/Soil Interaction

1998 ◽  
Author(s):  
Michael J. Paulin ◽  
Ryan Phillips ◽  
Jack I. Clark ◽  
Alan Trigg ◽  
Ibrahim Konuk
Keyword(s):  
Large Scale ◽  
Oil And Gas ◽  
Full Scale ◽  
Test Facility ◽  
Buried Structures ◽  
Specific Data ◽  
Nonlinear Springs ◽  
Comparative Results ◽  
Anchor Plates ◽  
Pipeline Design

The ability of oil and gas pipelines to respond safely to soil movements is an important consideration in pipeline design and route selection. There are a number of suggested methods of analysing pipeline/soil interaction in the literature most of which consider the pipeline to be connected to the soil via a series of discrete nonlinear springs. Many of these methods have generally been based on soil/structure interaction studies developed for other types of buried structures such as anchor plates and vertical piles. There are few pipeline-specific theoretical or experimental results available for comparison and validation of accepted design/analysis methods. To remediate this lack of large-scale pipeline-specific data, a full-scale pipeline/soil interaction test facility has been established in St. John’s Newfoundland. This paper presents a description of the test facility, details on experimental procedures, and comparative results from lateral and axial testing in sand and clay.

Large-Scale Tests of Pyrotechnically Generated Aerosol Fire Extinguishing Systems for the Protection of Machinery Spaces and Gas Turbine Enclosures in Royal Naval Warships

2004 ◽  
Author(s):  
Martin Connell ◽  
James L. D. Glockling ◽  
Fiona Neads
Keyword(s):  
Carbon Dioxide ◽  
Gas Turbine ◽  
Large Scale ◽  
Montreal Protocol ◽  
Test Facility ◽  
Fuel Spray ◽  
Royal Navy ◽  
Hold Period ◽  
Machinery Space ◽  
Large Scale Tests

The first Royal Navy Destroyer for over 20 years is due to enter service in 2007. The base design for fire protection of the main machinery space (first shot) and Gas Turbine enclosure is by a carbon dioxide total flooding system. Ministry of Defence policy precludes the use Halon as part of the implementation of the Montreal Protocol on new construction ships. Carbon dioxide although the preferred solution for the T45 Destroyer is inherently toxic and places large demands on storage areas and makes this far from the ideal solution. Since 2001, the T45 Destroyer Warship Integration Team has been advancing the testing of two pyrotechnically generated aerosol systems as a replacement for carbon dioxide systems. Large-scale tests of aerosol agents were carried out at Darchem Flares IMO facility (internal dimensions 10m × 10m × 5m high) near Darlington, UK. The test programme was loosely based around the IMO (International Maritime Organisation) MSC/Circ. 1007 protocol but with greater amounts of clutter in the facility and more representative of a warship’s machinery space. Fire scenarios were also modified to make them more representative of naval circumstances with the pass criteria as specified in IMO MSC/Circ 1007 specification: • Class B fires extinguished within 30 seconds; • 15 minute hold period (no re-ignition); • fuel spray shut off 15 seconds after fire extinguishment; • at the end of hold period fuel spray should be restarted for 15 seconds with no re-ignition evident; • at the end of the test fuel trays must have sufficient fuel remaining to cover bottom of tray. In addition to the large-scale testing aerosol fire testing was conducted on a faithful replica of a Gas Turbine enclosure. The GT mock-up enclosure was designed to replicate in service thermal and airflow conditions within the gas turbine enclosure prior to the fire scenario and release of the agent. A hazard assessment was carried out by a focus group to determine expected fire conditions within the enclosure and these were replicated in a number of fire tests to evaluate the performance of the aerosols. Although derived from a common background and described by common terminology, very stark performance differences were found between the two systems tested. This paper will describe the test facility, tests carried out, performance result’s and proposed future use of pyrotechnic fire suppression aerosols within the Royal Navy.

Evaluation of the accuracy of design methods for geosynthetic-reinforced piled embankments

2019 ◽  
Vol 56 (6) ◽  
pp. 761-773 ◽  
Author(s):  
Ewerton C.A. Fonseca ◽  
Ennio M. Palmeira
Keyword(s):  
Analytical Methods ◽  
Large Scale ◽  
Design Methods ◽  
Statistical Analyses ◽  
Statistical Criterion ◽  
Predictive Capability ◽  
Precise Method ◽  
Piled Embankment ◽  
Large Scale Tests ◽  
Piled Embankments

Geosynthetic-reinforced piled embankments have been increasingly used as a solution to stabilize embankments on soft subgrades. Analytical methods have been commonly used in routine designs of such works and significant deviations between results can occur depending on the method considered. This paper investigates the accuracy of different analytical methods by comparing their predictions with results of large-scale tests. A section of piled embankment consisting of an instrumented fill layer subjected to varying values of surface surcharge was simulated in the laboratory. Four different reinforcement types were tested. Results of the tests are presented and discussed, and statistical analyses were carried out to assess the accuracy of each method with regard to pile efficacy, maximum fill settlement, and reinforcement strain. Results show that the identification of the most accurate and precise method depends on the statistical criterion used. However, in general, the methods based on the concentric arches theory, the modified British method (BS8006), and the German method (EBGEO) were the ones that showed the best predictive capability.

Qualification of Welding Procedures for ExxonMobil High Strain Pipelines

2006 ◽  
Author(s):  
Martin W. Hukle ◽  
Douglas S. Hoyt ◽  
James B. LeBleu ◽  
John P. Dwyer ◽  
Agnes M. Horn
Keyword(s):  
Large Scale ◽  
High Strain ◽  
Soil Liquefaction ◽  
Critical Element ◽  
Test Program ◽  
Offshore Installations ◽  
Proof Testing ◽  
Girth Welds ◽  
Fault Displacement ◽  
Pipeline Design

Weld procedure qualification methodologies for ExxonMobil high strain pipelines are presented. ExxonMobil has been involved in the design and construction of high strain pipelines for both onshore and offshore applications. These projects have included onshore applications involving potential seismic activity (fault displacement and soil liquefaction) as well as arctic applications that may involve displacements associated with frost heave and thaw settlement. Recent offshore installations have been designed and constructed to accommodate potential displacement caused by ice scour. Some of these installations have been designed to accommodate in excess of 3% longitudinal tensile strain demand. A critical element of the overall pipeline design is the qualification and validation of acceptable strain capacity for the pipeline girth welds. A girth weld qualification test program, based on large scale proof testing (i.e., curved wide plates) has been developed and executed.

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