Recent developments of large diameter X80 UOE line pipes

High-strength pipeline steel and large diameter line pipes are often used to increase the capacity of transportation and reduce the cost associated with the construction and operation of long-distance gas pipeline projects. China＇ s initiatives to construct long-distance natural gas pipelines has brought in new opportunities for the development of X80 line pipes. Baosteel has designed the optimum chemical composition of X80 with high niobium and low molybdenum content. In addition, a welding experimental platform and a finite element model （FEM） have supported the development of X80 UOE pipes in an efficient and economical way. The application and recent development of X80 UOE pipes were introduced in this paper. To comply with the requirements of the Second West-East Gas Pipeline Project （2^nd WEPP ）, X80 pipeline steel with low carbon bainite microstructure was developed by utilizing the optimized composition and TMCP process. The matching welding material, welding procedure and UOE forming processes for 1 219mm outside diameter X80 UOE pipes were also developed. More than 340 000 t of X80 UOE pipes were produced and applied in the 2^nd WEPP. Furthermore, to meet the prospective demand for long-distance gas pipelines with an annual transportation capacity of over 40 billion m3 ,larger size X80 UOE pipes with 1 422 mm OD × 30. 8 mm WT were trial produced recently. DWTT performance, the main technical challenge for heavier wall pipes, was improved by using optimized microstructural design. The newly developed X80 pipes can be potentially used for larger transportation capacity pipelines in China.

Vertical vibration of a large diameter pipe pile considering transverse inertia effect of pile

Considering the transverse inertia effect of pile, the vertical soil layer is studied. The wave propagations in the outer and inner soil dynamic response of a large diameter pipe pile in viscoelastic are simulated by three-dimensional elastodynamic theory and those in the pile are simulated by Rayleigh-Love rod theory. The vertical and radial displacements of the outer and inner soil are obtained by utilizing Laplace transform technique and differentiation on the governing equations of soils. Then, based on the continuous conditions between the pile and soils, the displacements of the pile are derived. The frequency domain velocity admittance and time domain velocity response of the pile top are also presented. The solution is compared to a classical rod model solution to verify the validity. The influences of the radii and Poisson ratio of pile on the transverse inertia effect of pile are analyzed. The parametric study shows that Poisson ratio and outer radius of pile have significant influence on the transverse inertia effect of large diameter pipe piles, while the inner radius has little effect.

Effect of Pipe Diameter on Electrochemical Behavior of Stainless Steel Type 304 Pipes in Tap Water

We investigated the effects of pipe diameter on the corrosion resistance of stainless steel type 304 pipes using electrochemical measurements. Compared to plate steel, pipes have harder physical properties and tend to be harder and showed greater permeability with decreasing inner diameter. We found that the maximum corrosion current density in the secondary active state, which is the starting point of secondary passivation, appeared in the polarization curve measurement in tap water. Similar to the Vickers hardness and the maximum current density in the secondary active state, the permeability tended to increase as the diameter decreased. This is thought to increase the amount of deformation-induced martensitic and increase corrosion susceptibility. The peak of the secondary active current density was clearly seen as the potential sweep speed was increased. In addition, potential sweep speed dependence was observed in the corrosion susceptibility evaluation of deformation-induced martensite. In comparison with acid treatment, the formation of deformation-induced martensite was considered to occur in the extreme surface layer. The maximum corrosion current density in the secondary active state is expected to be a new susceptibility evaluation method for evaluating the deformation-induced martensitic transformation.

Optimization Design of Multi-hole and Varied Diameter Pipe Based on RAGA

Combining real accelerating genetic algorithm(RAGA) with the optimization design of multi-hole and varied diameter pipe, the authors solved the problem of optimizing multi-dimensional parameters at the same time. In which the advanced convergence and easily to run into partial optimization were avoid. Applied the RAGA to solving the problem in the optimization design of fixed piping sprinkler irrigation system. The optimized parameters, such as diameters and the length of pipe were calculated and the result was reasonable, which provides as a reference to readers who work at related research.

Study of an Ultrasonic Probe Installed into a Small Diameter-Pipe Using an Electromagnetic Acoustic Transducer

Metal pipes having an inner diameter of about 25 mm or less are frequently used as heat exchangers for power plants, gas pipes, and water pipes. However, erosion and corrosion due to long-term use may cause serious accidents, such as steam leaks, resulting in economic loss and environmental pollution. Therefore, inspection of the entire length and thickness before shipping or monitoring during operation are important technologies. However, no inspection technology including the inside of the wall thickness has been developed. The purpose was to develop an ultrasonic probe that can inspect the inner and outer surfaces from the inside of the pipe at the same time. The developed ultrasonic probe is based on an electromagnetic ultrasonic transducer (EMAT) that does not require a couplant and is then easy to install in a pipe. The EMAT for the longitudinal and for the transverse vibration mode guided wave are connected in series in order to take into account the variety of defects. First, the EMAT was successfully developed for each mode. That is, it was conducted by using the magnetostrictive effect for the longitudinal mode type and by using the Lorentz force for the transverse mode type, and evaluated to improve the performance. The reflected signal from a notch defect was then evaluated in the state that each EMAT was connected in series using any artificial defects and found to be able to detect any notches with about 10% depth or about 15% circumferential length.

Manufacturing Technology Research and Appraisal of Large-Diameter SSAW Pipe Applied to the West-East Pipeline Project

This paper introduced the research and development of large-diameter SSAW pipes applied to West-East Pipeline project as well as domestic acicular ferrite pipeline steel of X70 grade. Its microstructure analysis was performed in comparison with the pipeline steel of a foreign steel plant (SPC). This paper introduced the research of welding procedures prior to SSAW pipe making and some new procedures and technologies used for West-East Pipeline Project, and appraised the practical level of Large-diameter SSAW pipe applied to the West-East Pipeline Project.

Effect of the Minimum Diameter and Its Relevant Parameters on Wool Quality

It is important to measure wool diameter as the wool quality depends on the fibre diameter D and its deviation CVD. According to IWTO standards, the fibre diameter parameters can be tested with the methods of Airflowmeter, DA; Sirolan-Laserscan, DL and CVDL; and OFDA, Do and CVDo. However, these parameters only characterize the average diameter and the variation between the fibres. A single fibre analyzer (SIFAN) can be used to measure fibre profile along the fibre and fibre tensile properties simultaneously. The results obtained from the four methods show that there are i) high relationships between Laserscan values and the results of Airflow, OFDA and SIFAN in the average diameters; ii) correlations between CVDL and CVDo or CVDave; iii) the high correlation between Dave-Dmia but a low correlation between Dave-Dmax; and iv) the relationships between the wool quality and the ratio of Dmln/Dave and Dmin/DL. Based on the results and discussions, the effective measurement of wool diameter should be the SIFAN method. The new parameters of Dmin/DL and Dmin/Dave are the useful value for the evaluation of wool quality in practice.

Diameter distributions in Pinus sylvestris L.stands:evaluating modelling approaches including a machine learning technique

The diameter distribution of trees in a stand provides the basis for determining the stand’s ecological and economic value,its structure and stability and appropriate management practices.Scots pine(Pinus sylvestris L.)is one of the most common and important conifers in Turkey,so a well-planned management schedule is critical.Diameter distribution models to accurately describe the stand structure help improve management strategies,but developing reliable models requires a deep understanding of the growth,output and constraints of the forests.The most important information derived by diameter distribution models is primary data on horizontal stand structure for each diameter class of trees:basal area and volume per unit area.These predictions are required to estimate the range of products and predicted volume and yield from a forest stand.Here,to construct an accurate,reliable diameter distribution model for natural Scots pine stands in the Türkmen Mountain region,we used Johnson’s SBdistribution to represent the empirical diameter distributions of the stands using ground-based measurements from 55 sample plots that included1219 trees in natural distribution zones of the forests.As an alternative,nonparametric approach,which does not require any predefined function,an artificial intelligence model was constructed based on support vector machine methodology.An error index was calculated to evaluate the results.Overall,both Johnson’s SB probability density function with a three-parameter recovery approach and the support vector regression methodology provided reliable estimates of the diameter distribution of these stands.

基于射流补水的水泵水轮机S特性改善研究

针对水泵水轮机的“S”特性提出了在导叶顶盖位置无叶区处加装注水管的解决方案,并模拟了注水管安装在不同位置时的“S”特性曲线,分析了加装注水管后转轮区域内流线及转轮各叶道流量的分布规律。结果表明,于导叶顶盖加装注水管可以有效改善转轮内部流动,减轻转轮和导叶内部流动的相互影响,减小叶道涡的尺寸,同时有效缓解了转轮各叶道流量分布不均的现象。在注水管处于无叶区中段和活动导叶附近时,对“S”特性的改善效果明显。

Some Unresolved Issues in Ocean Pipes Aspirating Fluid

This paper reviews the dynamics of ocean pipes aspirating fluid and presents a selective review of the research undertaken on it. It focuses on the equations of motion, fluid-solid interaction at the inlet of the free end of the pipe, the stability mechanism of pipes aspirating steady fluid, etc. In particular, some unresolved or partly resolved issues on these important aspects are discussed. Finally, the promising future development in this area is discussed.

Asymptotic solutions of the flow of a Johnson-Segalman fluid through a slowly varying pipe using double perturbation strategy

A double perturbation strategy is presented to solve the asymptotic solutions of a Johnson-Segalman （J-S） fluid through a slowly varying pipe. First, a small parameter of the slowly varying angle is taken as the small perturbation parameter, and then the second-order asymptotic solution of the flow of a Newtonian fluid through a slowly varying pipe is obtained in the first perturbation strategy. Second, the viscoelastic parameter is selected as the small perturbation parameter in the second perturbation strategy to solve the asymptotic solution of the flow of a J-S fluid through a slowly varying pipe. Finally, the parameter effects, including the axial distance, the slowly varying angle, and the Reynolds number, on the velocity distributions are analyzed. The results show that the increases in both the axial distance and the slowly varying angle make the axial velocity slow down. However, the radial velocity increases with the slowly varying angle, and decreases with the axial distance. There are two special positions in the distribution curves of the axial velocity and the radial velocity with different Reynolds numbers, and there are different trends on both sides of the special positions. The double perturbation strategy is applicable to such problems with the flow of a non-Newtonian fluid through a slowly varying pipe.

Diameter信令网业务模型研究及展望

随着4G业务的发展,控制面网元对Diameter信令网的支撑要求与日俱增;本文分析了Diameter信令网面临的问题,提出了应对策略及建议,同时,分析了目前中国移动的S6a接口业务特性,结合现网历史统计数据以及信令流程特征,提出了业务模型的核定方法,使得Diameter信令网资源配置能够更符合未来4G业务发展的实际需求,最后展望了Diameter信令网未来演进方向。

Automated Pipe Routing Optimization for Ship Machinery

In the shipbuilding industry,market competition is currently operating in an intense state.To be able to strive in the global market,the shipbuilders must able to produce ships that are more efficient and can be constructed in a relatively short amount of time.The piping layouts in the engine room requires a lot of time for the designer to design the best possible route and in a way are not the most efficient route.This paper presents an automatic piping support system in the ship’s engine room based on the Dijkstra’s algorithm of pathfinding method.The proposed method is focused on finding the shortest possible route with a consideration of the following things:cost of the bend pipe,cost of the crossing pipe,cost reduction by pipe support,restriction on piping,reduction of calculation time,and design procedure of piping route.Dijkstra’s shortest path algorithm is adopted to find the shortest path route between the start and goal point that is determined based on the layout of the ship’s engine room.Genetic algorithm is adopted to decide the sequence of the pipe execution.The details of the proposed method are explained in this paper.This paper also discusses the application of the proposed method on an actual ship and evaluates its effectiveness.

Ultimate Bending Capacity of Strain Hardening Steel Pipes

Based on Hencky＇s total strain theory of plasticity,ultimate bending capacity of steel pipes can be determined analytically assuming an elastic-linear strain hardening material,the simplified analytical solution is proposed as well.Good agreement is observed when ultimate bending capacities obtained from analytical solutions are compared with experimental results from full-size tests of steel pipes.Parametric study conducted as part of this paper indicates that the strain hardening effect has significant influence on the ultimate bending capacity of steel pipes.It is shown that pipe considering strain hardening yields higher bending capacity than that of pipe assumed as elastic-perfectly plastic material.Thus,the ignorance of strain hardening effect,as commonly assumed in current codes,may underestimate the ultimate bending capacity of steel pipes.The solutions proposed in this paper are applicable in the design of offshore/onshore steel pipes,supports of offshore platforms and other tubular structural steel members.

Corrosion characteristics and mechanism of the S135 drill pipes in slurry

The corrosion mechanism of the S135 drill pipes was investigated through observation of the corrosion morphology and analysis of the corrosion products by scanning electronic microscope （ SEM）, energy dispersive spectrum （EDS） and X-ray diffraction （XRD）. The results show that the localized corrosion on the outer surface of the drill pipes was caused by oxygen corrosion due to the action of retained slurry. Cl - contained in slurry accelerated the corrosion and promoted the development of corrosion pits. Suggestions for mitigating or preventing such corrosion of the drill pipes are proposed based on the research results.

Hot Blast Flow Measurement in Blast Furnace in Straight Pipe

This article shows an innovative method to model and validate the hot air flow through the blast furnacés tuyeres. This study will be the basis for flow measurements implementation and safety interlocks for the pulverized coal injection. The flow measurements were taken in the blast furnace down leg pipes by installing refractory Venturi tubes. The system for the calculation of differential pressure takes into consideration the dimension of the Venturi, the air density and compressibility. The objective is to specify the flow transmitters required to automate a control system and implement safety interlocks for the coal injection plant.

Research & Development of Grade X70 LSAW Steel Pipes for West-East Gas Pipeline

In this article the research and development of X70 large diameter longitudinal seam submerged arc welded (LSAW) steel pipes for West East Gas Transportation Pipeline project (WEGTP) in China are introduced, including the key technique, fabrication of pipe production line, mass production and the latest progress of LSAW steel pipe technique.

D610含H_(2)S天然气集输管道材料选择

四川盆地大庆流转区块主要分布于川中、川东北及西昌盆地,地下天然气储量丰富,基此背景,大庆油田开展合深4区块开发先导试验项目,经前期试采开发分析,工程开采天然气中H_(2)S含量为1.5%,如何选择输送含有H_(2)S的天然气管道材质是保证项目安全平稳运行的关键。目前,国内含硫化氢天然气集输管道集中为D508及以下管径,项目应用的D610管径在以往工程中暂无应用,通过对国内外含H_(2)S天然气输送管道材质选择标准规范归纳总结,分析H_(2)S腐蚀机理,经与国内知名厂家、管材研究所深入调研,项目D610管径输送含H_(2)S天然气集输管道材质选择为抗硫直缝埋弧焊钢管,以此保证管道安全平稳运行,可为国内同类项目提供借鉴。

New indices to balanceα-diversity against tree size inequality

The number and composition of species in a community can be quantified withα-diversity indices,including species richness(R),Simpson’s index(D),and the Shannon-Wiener index(H΄).In forest communities,there are large variations in tree size among species and individu-als of the same species,which result in differences in eco-logical processes and ecosystem functions.However,tree size inequality(TSI)has been largely neglected in studies using the available diversity indices.The TSI in the diameter at breast height(DBH)data for each of 99920 m×20 m forest census quadrats was quantified using the Gini index(GI),a measure of the inequality of size distribution.The generalized performance equation was used to describe the rotated and right-shifted Lorenz curve of the cumulative proportion of DBH and the cumulative proportion of number of trees per quadrat.We also examined the relationships ofα-diversity indices with the GI using correlation tests.The generalized performance equation effectively described the rotated and right-shifted Lorenz curve of DBH distributions,with most root-mean-square errors(990 out of 999 quadrats)being<0.0030.There were significant positive correlations between each of threeα-diversity indices(i.e.,R,D,and H’)and the GI.Nevertheless,the total abundance of trees in each quadrat did not significantly influence the GI.This means that the TSI increased with increasing spe-cies diversity.Thus,two new indices are proposed that can balanceα-diversity against the extent of TSI in the com-munity:(1−GI)×D,and(1−GI)×H’.These new indices were significantly correlated with the original D and H΄,and did not increase the extent of variation within each group of indices.This study presents a useful tool for quantifying both species diversity and the variation in tree sizes in forest communities,especially in the face of cumulative species loss under global climate change.

Yandai Xiejie A Tobacco Pipe on Beijing’s Map

YANDAI Xiejie,or Tobacco Pipe Oblique Street,lies north of Di’anmen(Gate of Earthly Peace) and in front of the Drum Tower.It’s the oldest street of its kind in Beijing.Running northeast to southwest, the 232-meter-long lane is shaped like the stem of a tobacco pipe.The pipe’s mouthpiece is at the street’s eastern entrance, while the western part turning south toward Yinding Bridge(Silver Ingot Bridge) appears to look like a pipe bowl,hence Yandai Xiejie’s name.