scholarly journals Comparison between Full Scale Tests and Small Scale Tests in Evaluating the Cracking Susceptibility of Line Pipe in Sour Environment.

1996 ◽  
Vol 36 (2) ◽  
pp. 229-234 ◽  
Author(s):  
Akihiko Takahashi ◽  
Takuya Hara ◽  
Hiroyuki Ogawa
Keyword(s):  
Full Scale ◽  
Small Scale ◽  
Line Pipe ◽  
Full Scale Tests

TurkStream Collapse Test Program

2018 ◽  
Author(s):  
Chris Timms ◽  
Doug Swanek ◽  
Duane DeGeer ◽  
Arjen Meijer ◽  
Ping Liu ◽  
...  
Keyword(s):  
Thermal Ageing ◽  
Full Scale ◽  
The Black Sea ◽  
Small Scale ◽  
Test Program ◽  
Line Pipe ◽  
Medium Scale ◽  
Collapse Resistance ◽  
Full Scale Tests ◽  
The Impact

The TurkStream pipeline project is designed to transport approximately 32 billion cubic meters of natural gas annually from Russia to Turkey under the Black Sea, with more than 85% of the deep-water route being deeper than 2000 m. The offshore section is intended to consist of two parallel lines, each approximately 900 km long. The preliminary stages of the front end engineering design (pre-FEED) phase was managed by INTECSEA. To support the analyses and design of the deepest portions, a full scale collapse test program was performed by C-FER Technologies (C-FER). This collapse test program, which included 62 full-scale collapse and pressure+bend tests, 54 medium-scale ring collapse tests, and hundreds of small-scale tests, was primarily aimed at measuring, quantifying and documenting the increase in pipe strength and collapse resistance resulting from the thermal induction heat treatment effect (thermal ageing) that arises during the pipe coating process. Two grades of 32-inch (813 mm) outside diameter (OD) line-pipe, SAWL450 and SAWL485 with wall thicknesses of 39.0 mm or 37.4 mm, respectively, were supplied from various mills for testing. The collapse test program objectives were as follows: • Determine the collapse resistance of line pipes originating from various pipe mills; • Determine the pressure+bend performance of line pipes originating from various pipe mills; • Measure the effect of thermal ageing on material and collapse testing results, including the impact of multiple thermal cycles; and • Evaluate the results of medium-scale ring collapse tests as compared to full-scale tests. This paper presents selected results of this work, along with some comparisons to predictive equations.

Full-Scale Step-Load-Hold Tests on X65 and X70 Line Pipe Steels

2020 ◽  
Author(s):  
Andrew Cosham ◽  
Brian N. Leis ◽  
Mures Zarèa ◽  
Fabian Orth ◽  
Valerie Linton
Keyword(s):  
Impact Energy ◽  
Full Scale ◽  
Small Scale ◽  
Battelle Memorial Institute ◽  
Pipe Steels ◽  
Line Pipe ◽  
Delayed Failure ◽  
Hold Period ◽  
Full Scale Tests ◽  
Scale Step

Abstract A time-delayed failure due to stress-activated creep (cold-creep) will occur if the applied load is held constant at a level above the threshold. The results of small and full-scale tests on line pipe steels conducted by the Battelle Memorial Institute and the British Gas Corporation in the 1960s and 70s indicated that the (empirical) threshold for a time-delayed failure was approximately 85–95% SAPF (straight-away-pressure-to-failure). The line pipe steels were Grades X52 or X60, and the full-size equivalent Charpy V-notch impact energy (where reported) did not exceed 35 J. The strength and toughness of line pipe steels has significantly increased over the decades due to developments in steel-making and processing. The question then is whether an empirical threshold based on tests on lower strength and lower toughness steels is applicable to higher strength and higher toughness steels. A Tripartite Project was established to answer this question. The Australian Pipelines and Gas Association (APGA), the European Pipeline Research Group (EPRG) and the Pipeline Research Council International (PRCI) collaborated in conducting six full-scale step-load-hold tests on higher strength and higher toughness steels. Companion papers present the other aspects of this multi-year project. The line pipe supplied for testing is summarised below. • Identifier — Dimensions and Grade — f.s.e. Charpy V-notch impact energy at 0 C • APGA [A] — 457.0 × 9.1 mm, Grade X70M, ERW — 263 J • EPRG [E] — 1016.0 × 13.6 mm, Grade X70M, SAWL — 165 J • PRCI [P] — 609.6 × 6.4 mm, Grade X65, SAWL — 160 J Six step-load-hold tests, each with four part-through-wall defects, were conducted. Test Nos. APGA 1 and 2, and Nos. EPRG 1 and 2 were conducted at Engie, France. Test Nos. PRCI 1 and 2 were conducted at EWI, USA. The full-scale tests, and associated small-scale testing, are described and discussed. A time-delayed failure due to stress-activated creep occurred in each of the step-load-hold tests. The failures occurred during a hold-period at 93.7–104.4% SAPF, after a hold of approximately 1.0–13.9 hours. The results of the six step-load-hold tests are consistent with a threshold for a time-delayed failure of approximately 90% SAPF.

Development of Fatigue Design Data for the Ormen Lange Offshore Project: An Overview

2006 ◽  
Author(s):  
Hans Olav Knagenhjelm ◽  
Oddvin O̸rjasæter ◽  
Per J. Haagensen
Keyword(s):  
Crack Growth ◽  
Full Scale ◽  
Small Scale ◽  
Formation Water ◽  
Worst Case ◽  
Vortex Induced Vibrations ◽  
Welding Defects ◽  
Condensed Water ◽  
Full Scale Tests ◽  
Full Scale Testing

The Ormen Lange offshore pipelines from shore to the field go through very difficult terrain creating freespans in the range 40–80m for the 30” lines. For the 6” lines long freespans will be present prior to burial and vortex induced vibrations (VIV) will give a contribution during laying due to strong currents. Using existing codes for fatigue calculation was giving too conservative results compared to the welding technology used and experience from SCR work showed that better S-N data should be expected. A dedicated program was started as part of the Ormen Lange (OL) technology verification program overseen by Norwegian Authorities. An overview of the results is presented here. A full evaluation of the data is not yet complete. Papers will be published later presenting the full technical details and dataprocessing. Fatigue test results from the OL pipeline fatigue verification are presented focusing on the following topics: • Defect sizes in pipeline production welds; • Contractor-A: 5G welding position; • Contractor-B: 2G welding position; • 6” pipe full scale testing; • 30” pipe full scale testing; • Residual stresses; • Crack growth tests and sector specimen fatigue tests in production environments. The following are a summary of the main test variables in the program: • Mapping of actual welding defects compared to AUT results. • Welds with varying misalignment (high/low) and lack of penetration (LOP) from installation contractors tested in air. • Welds with natural welding defects in internal environment (Condensed water and formation water). • Welds with notches made by electrical discharge machining (EDM) (2×65mm and 2×15mm) in internal environment (condensed water and formation water). • Crack growth tests using large compact tension (CT) specimens in air, seawater and internal product environments (condensed water and formation water). • Full scale tests including worst case high/low, LOPs, and tests with normal welds including repair welds. The following main conclusions can be drawn from the work: • Small scale testing with representative worst case defects predicts well large scale testing results with the same features when the small scale specimen stresses are corrected for bending moments etc. arising from the cutout of the pipe. • Full scale testing of 30”×35.5mm wall thickness 2G pipes welded continuously (without start/stop) with worst case defects and high/low exceeds the D curve. • Full-scale tests of 30”×35.5mm wall thickness 5G non continuous welds with worst case defects and high/low exceeds the E curve. • Pipe welds showed low or even compressive residual stresses in the root. For continuously welded pipes the stress levels were low but more varying, also on the cap side. This partly explains the good results. • It is verified that the fatigue loads during operation are below the threshold of crack growth, and thus fatigue will not be a probable failure mechanism. This is under the condition that the measurements of vortex induced vibrations (VIV) during operation confirm the engineering calculations.

Full-Scale Reeling Tests of HFI Welded Line Pipe for Offshore Reel-Laying Installation

2014 ◽  
Author(s):  
Karl Christoph Meiwes ◽  
Susanne Höhler ◽  
Marion Erdelen-Peppler ◽  
Holger Brauer
Keyword(s):  
Mechanical Testing ◽  
Mechanical Test ◽  
Strength Properties ◽  
Full Scale ◽  
Bending Test ◽  
Small Scale ◽  
Pipe Material ◽  
Deformation Capacity ◽  
Line Pipe ◽  
Tension And Compression

During reel-laying repeated plastic strains are introduced into a pipeline which may affect strength properties and deformation capacity of the line pipe material. Conventionally the effect on the material is simulated by small-scale reeling simulation tests. For these, coupons are extracted from pipes that are loaded in tension and compression and thermally aged, if required. Afterwards, specimens for mechanical testing are machined from these coupons and tested according to the corresponding standards. Today customers often demand additional full-scale reeling simulation tests to assure that the structural pipe behavior meets the strain demands as well. Realistic deformations have to be introduced into a full-size pipe, followed by aging, sampling and mechanical testing comparable to small-scale reeling. In this report the fitness for use of a four-point-bending test rig for full-scale reeling simulation tests is demonstrated. Two high-frequency-induction (HFI) welded pipes of grade X65M (OD = 323.9 mm, WT = 15.9 mm) from Salzgitter Mannesmann Line Pipe GmbH (MLP) are bent with alternate loading. To investigate the influences of thermal aging from polymer-coating process one test pipe had been heat treated beforehand, in the same manner as if being PE-coated. After the tests mechanical test samples were machined out of the plastically strained pipes. A comparison of results from mechanical testing of material exposed to small- and full-scale reeling simulation is given. The results allow an evaluation of the pipe behavior as regards reeling ability and plastic deformation capacity.

scholarly journals Some Aspects of the Comparison of Model and Full Scale Tests

1925 ◽  
Vol 29 (175) ◽  
pp. 299-332
Author(s):  
D. W. Taylor
Keyword(s):  
United States ◽  
Advisory Committee ◽  
Human Life ◽  
The United States ◽  
Full Scale ◽  
Large Field ◽  
Small Scale ◽  
Free Flight ◽  
Flight Tests ◽  
Full Scale Tests

Aeronautics now covers a large field. The bibliography alone, compiled and published annually by the United States National Advisory Committee for Aeronautics, requires something like two hundred pages of a book seven inches by ten inches. Needless to say, I am not undertaking to review the whole field.Owing to the difficulties of conducting free flight tests of performance and the fact that we cannot afford to make many mistakes in an appliance whose operation involves the risk of human life, it is peculiarly desirable that we may be able to predict the performance of the completed airplane from small-scale experiments; and probably in no other branch of mechanical science have we at present so many research laboratories.

Performance Evaluation of High Quality HFW Linepipe by a Series of Full-Scale Pipe Tests

2014 ◽  
Author(s):  
Satoshi Igi ◽  
Teruki Sadasue ◽  
Kenji Oi ◽  
Satoru Yabumoto ◽  
Shunsuke Toyoda
Keyword(s):  
Fracture Toughness ◽  
Low Temperature ◽  
Internal Pressure ◽  
Fatigue Test ◽  
Full Scale ◽  
Safety Performance ◽  
Small Scale ◽  
High Quality ◽  
Burst Test ◽  
Full Scale Tests

Newly-developed high quality high frequency electric resistance welded (HFW) linepipes have recently been used in pipelines in reel-lay applications and low temperature service environments because of their excellent low temperature weld toughness and cost effectiveness. In order to clarify the safety performance of these HFW linepipes, a series of full-scale tests including a hydrostatic burst test at low temperature, fatigue test and tension test under high internal pressure was conducted, together with small-scale tests such as impact energy and standard fracture toughness tests, which are generally used in mill production and pre-qualification tests. The Charpy transition curve of the developed HFW pipe occurred at a temperature much lower than −45°C. Based on the low-temperature hydrostatic burst test with a notched weld seam at −45°C, the weld of the HFW linepipe presented the same level of leak-before-break (LBB) behavior, as observed in UOE pipes. A full-pipe fatigue test of HFW pipes with repeated internal pressurizing was conducted. The fatigue strength of the developed HFW linepipe shows better performance than butt weld joints because of the smoothness at its weld portion, which is achieved by mechanical grinding of the weld reinforcement. Full-scale pipe tensile tests of girth welded joints were performed with an artificial surface notch at the heat affected zone in the girth weld. The influence of internal pressure was clearly observed in these tests. Based on the above-mentioned full-scale tests, the safety performance of high quality HFW linepipe is discussed in comparison with the mechanical properties in the small-scale tests such as the Charpy and standard fracture toughness tests, especially when the notch was placed in the welded seam.

Interliner Effect on the Fire Performance of Upholstery Materials

1993 ◽  
Vol 11 (1) ◽  
pp. 87-105 ◽  
Author(s):  
James A. Gallagher
Keyword(s):  
Heat Release ◽  
Full Scale ◽  
Small Scale ◽  
Glass Cloth ◽  
Fire Performance ◽  
Fire Propagation ◽  
State Heat ◽  
Upholstered Furniture ◽  
Full Scale Tests ◽  
Selection Of

Sample screening can be an effective tool for understanding the fire problem of upholstered furniture. A study of the contribution of the com ponents of furniture construction to the heat release will permit the selection of materials which will be more likely to pass full scale tests. Component con tribution is complicated by fabric treatments and the use of interliners. Unless the interaction of these components during the crucial fire propagation phase is understood, no direction for improvement can be obtained from either full or small scale testing. By identifying the relevant interactions the selection of upholstery materials can be made more judiciously. The heat release of selected foam/interliner/fabric combinations, using the Ohio State Heat Release Calorimeter, shows that the heat release contribution of various upholstery components can be identified. For foams covered with fabric, interliners generally improve the performance of those foams which pass California TB 117 while detracting from the performance of those which pass California TB 133 (with no covering). For certain fabrics which melt, the heat release at low flux is independent of the type of foam, or even the presence of foam, when a glass cloth interliner is used. Fabric backings are shown to con tribute to fire propagation, particularly when no interliners are used. Because the heat release increases when the fabric is back-coated, thermal decomposi tion of the underlying foam is increased with an interliner.

Seamless Linepipe Response Under Small and Full Scale Reeling Simulation

2016 ◽  
Author(s):  
Israel Marines-Garcia ◽  
Jorge A. Aldana-Díaz ◽  
Philippe P. Darcis ◽  
Hector M. Quintanilla
Keyword(s):  
Lead Time ◽  
Cyclic Strain ◽  
Extensive Study ◽  
Full Scale ◽  
Small Scale ◽  
Pipe Material ◽  
Line Pipe ◽  
Offshore Pipelines ◽  
Ageing Condition ◽  
Pipe Materials

Offshore pipelines projects, installed by reel-laying operations, are gaining momentum due to the increasing worldwide capacity of Reel Lay Vessels. It is well known that reel-laying installation causes repeated plastic straining (cyclic deformation) and, as a consequence, cyclic strain and ageing test is usually required for qualifying line pipe materials for such installation method. This qualification is typically named reeling simulation. Reeling simulations can be made via full or small scale. In practice, full scale qualification lead time and full scale reeling simulation machines availability could be a constraint, thus, small scale reeling simulation is usually the best alternative. However, the similitude of small scale versus full scale simulations could be questioned. On this basis, an extensive study was carried-out considering tensile, toughness and sour testing, in order to evaluate the material response after reeling simulation, in order to clarify if the line pipe material will behave similarly regardless the straining method (small scale or full scale). Different small scale samples configuration for straining were tested, depending on the posterior mechanical or sour test, and two different full scale reeling simulation machines were used for plain pipes straining. Five seamless plain pipes, X65 line pipe were used for this study, with 3 (three) different outer diameters of 10.75″, 11.67″ & 16″ (273 mm, 296 mm & 406 mm). The current paper will present the main mechanical results of these materials after strain and ageing condition, comparing full and small scale straining methods.

Anisotropic HFI Welded Steel Pipes for Strain Based Design

2016 ◽  
Author(s):  
Oliver Hilgert ◽  
Susanne Höhler ◽  
Holger Brauer
Keyword(s):  
Full Scale ◽  
Small Scale ◽  
Steel Tubes ◽  
Line Pipe ◽  
Welded Steel ◽  
Bending Tests ◽  
Strain Capacity ◽  
Steel Pipes ◽  
Weld Material ◽  
Anisotropy Parameters

Generally isotropic behavior is assumed and demanded in line pipe specifications. Especially in strain based design, compressive and tensile strain capacity models rely on iso-tropic assumptions. On the other hand every pipe has got an anisotropic material characteristic which effects the performance in strain based design. In this contribution HFI-welded steel tubes are investigated due to their underlying material anisotropy. Depending on their basic strip weld material and production process the anisotropy differs from UOE or spiral welded pipes. Especially, in radial direction of steel pipe mechanical properties are challenging to gain. Thus two methods are suggested to characterize the anisotropic parameters in all three pipe directions. A small scale approach evaluating Lankford values and a full scale method evaluating Hill factors are applied. While Lankford method relies on strains, Hills method relies on stresses. Both methods are explained and validated by internal pressure and full scale bending tests. Using the anisotropy parameters, their effect on strain based design is analyzed — both experimentally and numerically. In the end it is shown that distinct anisotropies can provide a benefit for HFI-welded steel tubes concerning strain capacity in strain based design applications.

Mechanical Integrity Modeling of Forge Welded Pipes for Offshore Applications

2012 ◽  
Author(s):  
Ganesan S. Marimuthu ◽  
Per Thomas Moe ◽  
Junyan Liu ◽  
Bjarne Salberg
Keyword(s):  
Weld Line ◽  
Base Material ◽  
Full Scale ◽  
Small Scale ◽  
Type Model ◽  
Model Parameters ◽  
Weld Quality ◽  
Line Pipe ◽  
Gurson Model ◽  
Mechanical Integrity

In this paper, we discuss how through-process multi-scale models can be designed and combined with properly constructed experiments in order to assess the mechanical integrity of forge welded connectors. Shielded Active Gas Forge Welding (SAG-FW) is a fully automatic solid state method for joining steel pipes and other metallic articles. After heating, welding occurs almost instantaneously when the mating surfaces of the metallic parts are brought into intimate contact at high temperature and co-deformed. The result is a metallic bond with properties similar to those of the base material. If mating surfaces have been properly prepared and are essentially free from oxides the forge weld line is completely indistinguishable even when studied under a microscope. However, improper surface finish, oxides and contaminants may contribute to reducing weld quality. The paper consists of analytical and experimental parts. First, approaches for modeling forge welding and weld integrity are assessed. Second, a Gurson-type model is studied in great detail as it appears to be the simplest and most promising concept in relation to quantitative modeling and testing of mechanical integrity of forge welds. Third, miniature notched specimens for determining parameters of a modified Gurson-model are proposed and evaluated in relation to small scale forge welding. The small scale forge welding method has been established in order to simulate full scale welding of for example line pipe and casing, but mechanical testing of small samples constitute a significant challenge. Fourth, a set of experiments is performed to further assess the concept, to the extent possible determine material parameters of the Gurson-model and to evaluate the effect of process parameter settings on the weld quality. Results from tests of welds with and without oxides are subsequently compared with results from tests of base material specimens. All tests have been performed for an API 5L X65 alloy. The results demonstrate that both capacity and ductility of the forge welds are similar to those of base material. Finally, Gurson-model parameters are assessed, and a comparison with physical observations is made. Further development of the small scale tests is needed. More extensive test programs should be performed and a comparison with full scale welding should be carried out. However, the experiments demonstrated that the proposed notched specimen designs complements conventional fracture mechanical tests (CT, SENT, SENB) or field tests proposed by various standards (Charpy, Izod, bend tests).

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