A hybrid Broyden family method and its applications in isothermal steady simulation for gas transmission pipeline

2010 ◽  
Author(s):  
Bo Xu ◽  
Jianting Li ◽  
Zhu Zhao ◽  
Deji Wang
Keyword(s):  
Transmission Pipeline ◽  
Steady Simulation ◽  
Broyden Family

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.

Remote Monitoring Systems for Detection of Contact by Unauthorized Construction Equipment and the Cathodic Protection Condition on Buried Pipelines

2004 ◽  
Author(s):  
Shozo Hatanaka ◽  
Masahiko Tange ◽  
Morio Sumiyama
Keyword(s):  
Signal Processing ◽  
Cathodic Protection ◽  
Remote Monitoring ◽  
Heavy Traffic ◽  
Construction Equipment ◽  
Monitoring Systems ◽  
Indirect Methods ◽  
Detection Systems ◽  
Transmission Pipeline ◽  
Remote Monitoring Systems

It is necessary to avoid spreading damage to the pipe when it is struck by construction equipment. It is difficult to install indirect methods (e.g. fiber optic sensors) for detection of construction equipment in heavy traffic areas. Therefore, remote monitoring systems, which can detect contact between such equipment and the steel of polyethylene-lined pipe, were developed and installed on a gas transmission pipeline (φ 600 mm, Length 9.4 km). Detection uses the change in pipe-to-earth resistance which is derived from inner pipe current and pipe to soil potential when contact occurs. Old and new data of pipe-to-earth resistance are continuously compared. If equipment contacts the steel pipe, pipe-to-earth resistance will drop below 100 Ω. The detection systems include maximal length sequence signal (pseudo-random signal) processing. This signal processing is superior for noise reduction. These systems also have remote monitoring of the cathodic protection condition (pipe to soil potential, current of coupons (probes), and transformer rectifier output voltage and current). From the office, pipeline lining and cathodic protection conditions are monitored at all times.

Simulation of the Flow Condition Near the Intake of a Pump Sump

2006 ◽  
Author(s):  
Shuhong Liu ◽  
Yong Li ◽  
Xianwu Luo ◽  
Yulin Wu
Keyword(s):  
Flow Condition ◽  
Water Surface ◽  
Free Water ◽  
Internal Flow ◽  
Free Water Surface ◽  
Pump Station ◽  
Vof Model ◽  
Calculation Results ◽  
Pump Sump ◽  
Steady Simulation

It is known that the flow condition in the pump sump is very complicated, which usually performs as several types of vortex, water wave of free surface, vibration, noise, and etc. To make clear the flow condition experimentally and numerically is very important to develop the performance and operating stability of the pump station. As one of the projects with Hitachi Industries ltd. Co., Japan, the investigation experimentally on the internal flow condition of the pump sump has been carried out in Tsinghua University. In this paper, we introduce the simulation results, which can show more detail information near the intake of the pump sump. The simulation is focused on the area near the intake, together with the extension of up-stream and down-stream. The calculation research includes two parts: steady simulation and unsteady simulation by VOF model, which is provided by the commercial software of Fluent. Through the steady simulation, the distribution of free water surface (water height) near the intake, as well as the flow condition inside the intake, were obtained. Comparing with the experimental data, a good agreement was observed. After analyzing the unsteady calculation results by VOF, four stages of the development of air-entraining vortex, and the wave characteristic of free water surface, were obtained, which were in accord with the experiment visualizing.

Preliminary Failure Assessment for Spiral Welded Defects of Pipeline

2008 ◽  
Author(s):  
Qingshan Feng ◽  
Yi-Han Lin ◽  
Fuxiang Wang ◽  
Bin Li
Keyword(s):  
Ultrasonic Inspection ◽  
Western China ◽  
Practical Significance ◽  
Oil Pipeline ◽  
Integrity Assessment ◽  
Failure Assessment ◽  
Transmission Pipeline ◽  
Collapse Failure ◽  
Inspection Data ◽  
Grade Assessment

The spiral welded defect of steel oil transmission pipeline is one of the main causes resulting in pipeline leakage accident. Hence the failure assessment for known-size spiral welded defects is an important step to ensure the safety of defected pipeline. Lack of suitable criterion for assessing the spiral welded manufacture defects of pipeline network in China, is a difficult technology problem to be solved desirably. This paper first summarized the basic idea of preliminary failure assessment (Grade 1A of code BS 7910:2005) with some insight of our own understanding, and then applied the preliminary failure assessment to the spiral welded defects of oil pipeline, with the use of ultrasonic inspection data of Daqing-Tieling old pipeline from LingYuan to XinMiao, Northeastern China. The calculation of both fracture and plastic collapse failure for spiral welded defects indicates some detected flaws of pipeline are not safe as the internal pressure is greater than 4.5 MPa. A leakage accident of spiral welded pipeline in Western China is also assessed through fractography analyses and failure calculations. This paper concludes that the preliminary failure assessment provides useful outcome for reference in making decision of inspection, integrity assessment and repair of spiral welded pipeline, and hence is a step of fundamental importance and practical significance before more accurate data becomes available for higher grade assessment.

Broyden Family of Methods and the BFGS Update

2008 ◽  
pp. 345-346
Author(s):  
Vassilios S. Vassiliadis ◽  
Raúl Conejeros
Keyword(s):  
Bfgs Update ◽  
Broyden Family
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