Application of Error-in-Variable Model (EVM) for Estimating Gas Pipeline Internal Wall Roughness Before and After Pigging

2016 ◽  
Author(s):  
Teresa Leung ◽  
Joel Smith ◽  
Trevor Glen ◽  
Will Runciman
Keyword(s):  
Surface Roughness ◽  
Pipe Wall ◽  
Surface Condition ◽  
Internal Surface ◽  
Measured Data ◽  
Wall Roughness ◽  
Wall Surface ◽  
Internal Wall ◽  
Variable Model ◽  
Before And After

Gas pipeline internal surface typically undergoes degradation for a variety of reasons such as fouling of the pipe inner surface, erosion, corrosion and deposits of objectionable materials that occasionally enter the gas stream at receipt points. Accurate monitoring of the pipe internal surface condition can hugely benefit the planning of cleaning activities. Theoretically the pipe wall roughness for a given pipe segment can be extracted based on measured flow data and other system parameters. The challenge lies in the fact that measured data all contain varying degrees of uncertainty, and the system becomes more complex to analyze when it contains different segments connected in series or parallel like many typical gas gathering and lateral networks. This paper demonstrates the application of the Error-in-Variable Model (EVM) using the Markov Chain Monte Carlo (MCMC) solution method in analyzing a complex pipeline network on the TransCanada NGTL System. EVM, a well-established Bayesian parameter estimation technique, accounts for uncertainties in the measured variables, such as flow and pressure data, when determining the most probable estimates of unknown parameters such as pipe internal wall surface roughness. In this work, the EVM problem is solved using the MCMC Metropolis-Hastings algorithm. The MCMC approach is demonstrated to be robust, easy to implement and capable of handling large quantities of data. It has the potential to analyze complex networks and monitor the pipe wall surface condition on-line with SCADA data. Using this method, the internal wall surface roughness for the segments of interest in this network were extracted from measured data collected before and after the pigging operation. Results demonstrate the model’s capability in estimating the degradation of the pipe wall internal surface and the effectiveness of pigging. Details on implementation and challenges in applying such methodology to analyze complex gas networks are discussed.

Measurements and Evaluation of Internal Wall Surface Roughness of Small Diameter Pipes for High Pressure Natural Gas Systems

2014 ◽  
Author(s):  
C. Hartloper ◽  
K. K. Botros ◽  
J. Geerligs ◽  
H. Golshan ◽  
K. Jensen
Keyword(s):  
Surface Roughness ◽  
Pipe Wall ◽  
Large Diameter ◽  
Roughness Parameter ◽  
Small Diameter ◽  
Wall Roughness ◽  
Roughness Parameters ◽  
Internal Wall ◽  
Effective Roughness ◽  
Pipe Size

The default roughness parameter values used in industry to determine the pressure loss through small diameter pipeline systems are much higher than the values employed in typical large diameter gas transmission and lateral systems. It is uncertain whether these higher roughness values are due to higher topological roughness of the internal wall of the small diameter pipes or if they are a result of other factors. Measurements were taken on 17 small diameter pipe samples in order to evaluate the pipe-wall roughness parameter. A model to calculate the effective roughness parameter, which takes into account pressure losses due to the measured roughness as well as internal welds and scaling, has been developed. The effective roughness parameter of these samples is found to range from 20.4μm to 62.9μm, an increase of 11.0μm to 23.3μm over the measured pipe-wall roughness parameter. This range of effective roughness parameters agrees well with the default range of 35μm to 65μm used in industry, as well as the literature quoted range for clean pipe of 40μm to 100μm. The measured roughness parameter on average increases with increasing nominal pipe size, a result that may be a characteristic of the extrusion or hot-rolling processes used to manufacture small diameter pipes. Additionally, there is a large variation in the measured roughness parameters of pipe samples of the same nominal pipe size, indicating that surface roughness can vary depending on the manufacturing source of these pipes.

Understanding Magnetic Flux Leakage Signals From Gouges

2010 ◽  
Author(s):  
Lynann Clapham ◽  
Vijay Babbar ◽  
Jian Dien Chen ◽  
Chris Alexander
Keyword(s):  
Magnetic Flux ◽  
Pipe Wall ◽  
Mechanical Damage ◽  
Internal Surface ◽  
Magnetic Flux Leakage ◽  
Wall Surface ◽  
Pipe Surface ◽  
Early Results ◽  
Flux Leakage ◽  
Wall Geometry

The Magnetic Flux Leakage (MFL) technique is sensitive both to pipe wall geometry and pipe wall strain, therefore MFL inspection tools have the potential to locate and characterize mechanical damage in pipelines. The present work is the first stage of a study focused on developing an understanding of how MFL signals arise from pipeline gouges. A defect set of 10 gouges were introduced into sections of 12″diameter, 5m long, end capped and pressurized X60 grade pipe sections. The gouging tool displacement ranged (before tool removal) between 2.5 to 12.5mm. Gouges were approximately 50mm in length. The shallowest indentation created only a very slight scratch on the pipe surface, the deepest created a very significant gouge. All gouges were axially oriented. Experimental MFL measurements were made on the external pipe wall surface (pressurized) as well as the internal surface (unpressurized). The early results of the experimental MFL studies, and a hypothesis for the origin of the MFLaxial signal “dipole” are discussed in this paper.

Surface roughness measurements of vanadium-contaminated fluidized cracking catalysts by atomic force microscopy

1996 ◽  
Vol 54 ◽  
pp. 866-867
Author(s):  
H. Kinney ◽  
M.L. Occelli ◽  
S.A.C. Gould
Keyword(s):  
Surface Roughness ◽  
Zeolite Y ◽  
Atomic Level ◽  
Microporous Structure ◽  
Contact Mode ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
Roughness Measurements ◽  
Cracking Catalysts

For this study we have used a contact mode atomic force microscope (AFM) to study to topography of fluidized cracking catalysts (FCC), before and after contamination with 5% vanadium. We selected the AFM because of its ability to well characterize the surface roughness of materials down to the atomic level. It is believed that the cracking in the FCCs occurs mainly on the catalysts top 10-15 μm suggesting that the surface corrugation could play a key role in the FCCs microactivity properties. To test this hypothesis, we chose vanadium as a contaminate because this metal is capable of irreversibly destroying the FCC crystallinity as well as it microporous structure. In addition, we wanted to examine the extent to which steaming affects the vanadium contaminated FCC. Using the AFM, we measured the surface roughness of FCCs, before and after contamination and after steaming.We obtained our FCC (GRZ-1) from Davison. The FCC is generated so that it contains and estimated 35% rare earth exchaged zeolite Y, 50% kaolin and 15% binder.

scholarly journals The Effects of Toothbrush Wear on the Surface Roughness and Gloss of Resin Composites with Various Types of Matrices

2021 ◽  
Vol 9 (1) ◽  
pp. 8
Author(s):  
Murtadha AlAli ◽  
Nikolaos Silikas ◽  
Julian Satterthwaite
Keyword(s):  
Surface Roughness ◽  
Pairwise Comparisons ◽  
Resin Composites ◽  
Hybrid Resin ◽  
Before And After ◽  
Post Hoc ◽  
Main Effects ◽  
Toothbrush Wear

Objective: To evaluate and compare the surface roughness and gloss of a DMA-free composite and Bis-GMA-free composite with a DMA-based composite before and after toothbrushing simulation. Materials and Methods: Fifteen dimensionally standardised composite specimens of three nano-hybrid resin composites (Tetric EvoCeram, Admira Fusion, and Venus Diamond) were used. Five specimens from each composite were polished and then subjected to a toothbrushing simulator. Surface roughness (Ra) and gloss were measured before toothbrushing and after 5000, 10,000, 15,000, and 20,000 toothbrushing cycles. The data was analysed using 5 × 3 ANOVA to assess surface roughness and gloss values and pairwise comparisons in the form of Tukey post hoc tests were performed to interpret main effects. Results: For all tested materials, surface roughness increased, and gloss decreased after toothbrushing abrasion. Surface roughness (Ra) values ranged from 0.14 to 0.22 μm at baseline and increased to between 0.41 and 0.49 μm after 20,000 toothbrushing cycles. Gloss values ranged between 31.9 and 50.6 GU at baseline and between 5.1 and 19.5 GU after 20,000 toothbrushing cycles. The lowest initial Ra value was detected in Venus Diamond and the highest initial gloss value was detected in Tetric EvoCeram. Conclusions: Simulated toothbrushing abrasion led to an increase in surface roughness and a decrease in gloss for all tested materials. Venus Diamond had the smoothest surface and Tetric EvoCeram had the glossiest surface after polishing and following 20,000 cycles of toothbrushing abrasion. Admira Fusion demonstrated the roughest surface and had the lowest gloss values before and after toothbrushing abrasion.

scholarly journals Perspective on the Response of Turbulent Pipe Flows to Strong Perturbations

Fluids ◽  
2021 ◽  
Vol 6 (6) ◽  
pp. 208
Author(s):  
Liuyang Ding ◽  
Tyler Van Buren ◽  
Ian E. Gunady ◽  
Alexander J. Smits
Keyword(s):  
Pipe Flow ◽  
Abrupt Change ◽  
Pipe Wall ◽  
Surface Condition ◽  
Initial Response ◽  
Body Of Revolution ◽  
Future Directions ◽  
Pipe Flows ◽  
Roughness Elements ◽  
Pipe Geometry

Pipe flow responds to strong perturbations in ways that are fundamentally different from the response exhibited by boundary layers undergoing a similar perturbation, primarily because of the confinement offered by the pipe wall, and the need to satisfy continuity. We review such differences by examining previous literature, with a particular focus on the response of pipe flow to three different kinds of disturbances: the abrupt change in surface condition from rough to smooth, the obstruction due to presence of a single square bar roughness elements of different sizes, and the flow downstream of a streamlined body-of-revolution placed on the centerline of the pipe. In each case, the initial response is strongly influenced by the pipe geometry, but far downstream all three flows display a common feature, which is the very slow, second-order recovery that can be explained using a model based on the Reynolds stress equations. Some future directions for research are also given.

Calibration of Mobility and Interface Trap Parameters for High Temperature TCAD Simulation of 4H-SiC VDMOSFETs

2012 ◽  
Vol 717-720 ◽  
pp. 1101-1104 ◽  
Author(s):  
M.G. Jaikumar ◽  
Shreepad Karmalkar
Keyword(s):  
Surface Roughness ◽  
Measured Data ◽  
Interface Trap Density ◽  
Interface Trap ◽  
Material Parameters ◽  
Velocity Saturation ◽  
Physical Mechanisms ◽  
Surface Roughness Scattering ◽  
Wide Range ◽  
Tcad Simulation

4H-Silicon Carbide VDMOSFET is simulated using the Sentaurus TCAD package of Synopsys. The simulator is calibrated against measured data for a wide range of bias conditions and temperature. Material parameters of 4H-SiC are taken from literature and used in the available silicon models of the simulator. The empirical parameters are adjusted to get a good fit between the simulated curves and measured data. The simulation incorporates the bias and temperature dependence of important physical mechanisms like interface trap density, coulombic interface trap scattering, surface roughness scattering and velocity saturation.

Contact Width Analysis of Corrugated Metal Gasket Based on Surface Roughness

2013 ◽  
Vol 856 ◽  
pp. 92-97 ◽  
Author(s):  
Shigeyuki Haruyama ◽  
Didik Nurhadiyanto ◽  
Ken Kaminishi
Keyword(s):  
Surface Roughness ◽  
The Real ◽  
Real Contact ◽  
Contact Width ◽  
Before And After ◽  
Optimizing Design ◽  
Roughness Evaluation ◽  
Helium Leakage ◽  
Corrugated Metal ◽  
Important Design

Contact width is important design parameter for optimizing design of new metal gasket. The contact width was found have relationship with helium leak quantity. Increasing axial force, the contact width will increase and helium leakage will decrease. This study we conducted the surface roughness evaluation of 25A-size metal gasket before and after use. The results denote the real contact width after contact with flange having different surface roughness. The real contact width for the flange having smoother surface roughness is wider than the rougher one.

Hydrogen Ion Beam Processing of Single Crystal Diamond Chips

1994 ◽  
Vol 354 ◽  
Author(s):  
Shuji Kiyohara ◽  
Iwao Miyamoto
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Incidence Angle ◽  
Ion Beam ◽  
Etching Rate ◽  
Hydrogen Ion ◽  
Hydrogen Ions ◽  
Ion Beam Etching ◽  
Single Crystal Diamond ◽  
Before And After

AbstractIn order to apply ion beam etching with hydrogen ions to the ultra-precision processing of diamond tools, hydrogen ion beam etching characteristics of single crystal diamond chips with (100) face were investigated. The etching rate of diamond for 500 eV and 1000 eV hydrogen ions increases with the increase of the ion incidence angle, and eventually reaches a maximum at the ion incidence angle of approximately 50°, then may decrease with the increase of the ion incidence angle. The dependence of the etching rate on the ion incidence angle of hydrogen ions is fairly similar to that obtained with argon ions. Furthermore, the surface roughness of diamond chips before and after hydrogen ion beam etching was evaluated using an atomic force microscope. Consequently, the surface roughness after hydrogen ion beam etching decreases with the increase of the ion incidence angle within range of the ion incidence angle of 60°.

Study of a Novel Honeycomb Continuous Flocculator

2014 ◽  
Vol 1033-1034 ◽  
pp. 435-438
Author(s):  
Ming Dong ◽  
Qiong Fang Shao
Keyword(s):  
Surface Roughness ◽  
Grain Size ◽  
Flow Resistance ◽  
Separation Efficiency ◽  
Sewage Treatment ◽  
Internal Surface ◽  
Industrial Fermentation ◽  
Fermentation Liquid ◽  
Solid Liquid ◽  
Solid Liquid Separation

The continuous flocculator described in this article refers to a kind of continuous flocculation device designed to flocculate fermentation liquid. The honeycomb continuous flocculator is composed of a vessel and built-in trapezoid subassemblies, which divide the space within the vessel into multiple honeycomb channels. The length ratio between the longest diagonal of the regular hexagon and the axial length of the channel is within the range 0.01–0.04; and the internal surface roughness (Ra) of the channels should be 0 < Ra ≤ 0.2 μm. In contrast to current flocculator designs, the channels of the honeycomb continuous flocculator could control the floc grain size, grain fineness distribution in the fermentation liquid and flocculating time and decrease the flow resistance of the flocculating fermentation liquid and increase handling capacity. These capabilities improve solid-liquid separation efficiency for fermentation liquids. The flocculator could be used either for purification of industrial fermentation liquids or sewage treatment.

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