Non-intrusive corrosion-erosion monitoring for subsea applications

2011 ◽  
Vol 51 (1) ◽  
pp. 543
Author(s):  
Geir Instanes ◽  
Sindre Kristiansen ◽  
Olav Brakstad
Keyword(s):  
Wall Thickness ◽  
Life Cycle Cost ◽  
Assessment Tool ◽  
Pipe Wall ◽  
Guided Wave ◽  
Operating Conditions ◽  
Metallic Surface ◽  
High Coverage ◽  
Pipe Surface ◽  
Ultrasonic Guided Wave

Detection and monitoring of corrosion and erosion are essential prognostic means in preserving material integrity and reducing the life-cycle cost of industrial infrastructure, ships, aircrafts, ground vehicles, pipelines, oil installations, etc. Even topside, the operating conditions can be extremely difficult, facing problems like pipe surface roughness, fluid loading, temperature variations, and a host of other factors that make development of a robust wall thickness assessment tool a challenging task. Deploying a monitoring system subsea makes the application even more demanding when factors such as high pressure and limited access must be taken into account. The ClampOn Corrosion-Erosion Monitor has already been successfully installed at several locations topside and is now in its final stages of the subsea development. Non-invasiveness, high repeatability and high coverage are among its advantages, making it an excellent candidate for subsea use. The technology is based on the dispersion of ultrasonic guided wave modes. By using electromagnetism these waves can be transmitted through the pipe wall without the sensor being in direct contact with the metallic surface. It is installed on the outer pipe wall to produce real-time wall thickness information, not as a spot measurement, but as a unique average path wall thickness.

A Novel Method of Estimating the Aspect Ratio of Pipe Wall Thickness to Diameter Utilizing the Characteristics of a Hollow Cylindrical Guided Wave

2004 ◽  
Author(s):  
Hideo Nishino ◽  
Noriyoshi Chubachi ◽  
Hideo Cho ◽  
Mikio Takemoto
Keyword(s):  
Aspect Ratio ◽  
Wall Thickness ◽  
Pipe Wall ◽  
Ultrasonic Method ◽  
Guided Wave ◽  
Pipe Wall Thickness ◽  
Time Frequency ◽  
Ultrasonic Guided Wave ◽  
Dc Component ◽  
Bar Velocity

We have developed a method of estimating the aspect ratio of a pipe wall thickness to diameter (t/d) using a hollow cylindrical guided wave (HCGW). The HCGW is an ultrasonic guided wave in a pipe. The method is very useful for onsite and nondestructive estimation of pipe wall thickness. It is based on the change of the dispersion relation of the HCGW as a function of t/d. The group velocity of the primary wave (first arriving wave packet from an impulse source) of the HCGW ranges from the bar velocity to the sheet velocity as a function of t/d. The bar velocity is the velocity of the DC component of the guided wave propagating in a solid cylinder; the sheet velocity is that of the S0 mode Lamb wave. The first part of the paper describes the principle of the method. In the last part, a laser ultrasonic method was employed to verify the method in both time- and time-frequency domains. The experimental results for aluminum pipes with various t/d’s were in good agreement with the theory.

The Application of Ultrasonic Guided Waves in the Furnace Tube Inspection

2013 ◽  
Author(s):  
Li Xia ◽  
Yufeng Ye ◽  
Xianggang Wang
Keyword(s):  
Wall Thickness ◽  
Guided Waves ◽  
Thickness Measurement ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Security Risks ◽  
Tube Wall Thickness ◽  
Ultrasonic Guided Wave ◽  
Furnace Tube ◽  
Crude Oil Distillation

According to the problem of the conventional thickness measurement method used to measure the furnace wall thinning in petrochemical industry, proposed a new NDT named guided wave to detect the presence of the wall thickness. Use of the technique for detection of dangerous parts of the refinery furnace tube, take the coker furnace and the furnace of crude oil distillation unit guided wave inspection application for Example, and through analysis of test data and field-proven and found many security risks, and guide the user to process. It concluded that the ultrasonic guided wave technology can effective realization radiation section of the furnace tube wall thickness detection.

Ultrasonic Circumferential Guided Wave for Pitting-Type Corrosion Imaging at Inaccessible Pipe-Support Locations

2008 ◽  
Vol 130 (2) ◽  
Author(s):  
K. Shivaraj ◽  
Krishnan Balasubramaniam ◽  
C. V. Krishnamurthy ◽  
R. Wadhwan
Keyword(s):  
Guided Waves ◽  
Pipe Wall ◽  
Element Model ◽  
Higher Order ◽  
Guided Wave ◽  
Structural Layout ◽  
Ultrasonic Guided Wave ◽  
Experimental Parameters ◽  
Data Acquisition Card ◽  
Pulse Echo

A higher order cylindrically guided ultrasonic wave was used for the detection and sizing of hidden pitting-type corrosion in the hidden crevice regions (between the pipe and the pipe supports) without lifting or disturbing the structural layout arrangement of the pipelines. The higher order circumferential guided waves were generated using a piezoelectric crystal based transducer, located at the accessible top region of the pipes, in a pulse-echo mode. By studying the experimental parameters such as dispersion, particle displacement, and wavelength of the ultrasonic guided wave modes, an appropriate higher order mode was selected for excitation using an appropriately designed acrylic angle wedge that conforms to the pipe’s outer curvature. A manual pipe crawler was designed with a provision for holding the wedge, and the essential hardware such as data acquisition card, encoder, etc., was integrated with the system so that the corrosion was mapped in real time during the scanning of the pipes. The system was validated on pipes ranging from 6in.to24in. outer diameters of wall thicknesses up to 12mm, by mapping defects as small as 1.5mm diameter and 25% penetration wall thickness. A 2D finite element model using ABAQUS® was used to understand the wave propagation in pipe wall and its interaction with pinhole-type defects.

Long Range Ultrasonic Guided Wave Technique for Inspection of Pipes

2006 ◽  
Vol 321-323 ◽  
pp. 799-803 ◽  
Author(s):  
Ik Keun Park ◽  
Yong Kwon Kim ◽  
Hyun Mook Kim ◽  
Won Joon Song ◽  
Yong Sang Cho
Keyword(s):  
Long Range ◽  
Cross Section ◽  
Wall Thickness ◽  
Guided Wave ◽  
Experimental Results ◽  
Thickness Reduction ◽  
Ultrasonic Guided Wave ◽  
Cross Section Area ◽  
Section Area ◽  
Wave Technique

Conventional non-destructive techniques for inspection of weld in pipelines require significant test time and high cost. In this paper, a study in the application of ultrasonic guided waves to long range inspection of the pipeline is presented. The characteristics and setup of a long range guided wave inspection system and experimental results in pipes of various diameters are introduced. The experimental results in mock-up pipes with cluster type defects show that the limit of detectable wall thickness reduction with this guided wave system is 2~3% in the pipe cross section area and the wall thickness reduction of 5% in cross section area can be detected when actual detection level is used. Therefore, the applicability of the ultrasonic guided wave technique to long range pipeline inspection for wall thickness reduction is verified.

The Eddy Current Method of Alloy Drill Pipes Wall Thickness Evaluation: Impact Analysis

2019 ◽  
Vol 970 ◽  
pp. 336-342
Author(s):  
Aleksandr E. Goldshtein ◽  
Vasily Y. Belyankov
Keyword(s):  
Wall Thickness ◽  
Eddy Current ◽  
Impact Analysis ◽  
Pipe Wall ◽  
Current Method ◽  
Eddy Current Method ◽  
Pipe Surface ◽  
Thickness Change ◽  
Pipe Wall Thickness ◽  
Aluminum Pipe

The dependences of the surface eddy current probe added voltage at the interaction of the probe magnetic field with an aluminum pipe from the following main interference factors are determined: the pipe wall thickness, the gap between the probe and the surface of the pipe, the electrical conductivity of the material, the curvature of the pipe wall, the presence of areas with a smooth thickness change of the wedge character and a local spherical thinning, axis misalignment with respect to the pipe surface, the lateral misalignment of the probe axis. The problem is solved with the help of the finite element method (FEM). These data are consistent with the experimental results.

Experimental Characterization of Flow Induced Vibration in Fully Developed Turbulent Pipe Flow

2009 ◽  
Author(s):  
Andrew S. Thompson ◽  
Daniel Maynes ◽  
Thomas Shurtz ◽  
Jonathan D. Blotter
Keyword(s):  
Wall Thickness ◽  
Pipe Wall ◽  
Wall Pressure ◽  
Surface Velocity ◽  
Pipe Diameter ◽  
Pipe Material ◽  
Pipe Surface ◽  
Pipe Wall Thickness ◽  
Wall Pressure Fluctuations ◽  
Pipe Vibration

In this paper we present results of an experimental investigation that characterizes the wall vibration of a pipe with a fully-developed turbulent flow passing through it. Experiments were conducted in a water flow loop where the influences of average fluid speed, pipe diameter, pipe wall thickness, and pipe material on the overall pipe vibration were investigated. The pipe vibration was characterized by accelerometer instruments mounted on the surface of the pipe at multiple locations and the rms of the pipe wall acceleration, velocity, and displacement were measured. Simultaneous measurements of the local temporal fluctuations in the wall pressure were also obtained. Specifically, experiments were conducted in test sections of internal diameters of 3.81 cm – 10.16 cm, pipe wall thickness to diameter ratio ranging from 0.06 – 0.10, and with PVC, aluminum, and stainless steel pipe materials. The experiments were conducted with average fluid speeds ranging from 0 – 11.5 m/s with an accompanying range in the dynamic pressure from 0 – 1 atm. The results show that the rms of the acceleration is proportional to the average fluid speed raised to the 2.12 power. Also, the rms of the pipe surface velocity and the pipe displacement scale with the average fluid speed to the 1.62 and 1.16 powers respectively. Further, the rms of the pipe acceleration and pipe speed increase with increasing pipe diameter, while the pipe modulus of elasticity appears to exert negligible influence on the magnitude of the measured vibrations. The rms of the wall pressure fluctuations scale with the fluid speed raised to the 2.0 power.

scholarly journals Ultrasonic Guided Wave-Based Circumferential Scanning of Plates Using a Synthetic Aperture Focusing Technique

2018 ◽  
Vol 8 (8) ◽  
pp. 1315 ◽  
Author(s):  
Jianjun Wu ◽  
Zhifeng Tang ◽  
Keji Yang ◽  
Shiwei Wu ◽  
Fuzai Lv
Keyword(s):  
Guided Waves ◽  
Angular Resolution ◽  
Sound Field ◽  
Guided Wave ◽  
Operating Conditions ◽  
Polar Coordinates ◽  
Synthetic Aperture ◽  
Ultrasonic Guided Wave ◽  
Experimental Validations ◽  
Synthetic Aperture Focusing

Tanks are essential facilities for oil and chemical storage and transportation. As indispensable parts, the tank floors have stringent nondestructive testing requirements owing to their severe operating conditions. In this article, a synthetic aperture focusing technology method is proposed for the circumferential scanning of the tank floor from the edge outside the tank using ultrasonic guided waves. The zeroth shear horizontal (SH0) mode is selected as an ideal candidate for plate inspection, and the magnetostrictive sandwich transducer (MST) is designed and manufactured for the generation and receiving of the SH0 mode. Based on the exploding reflector model (ERM), the relationships between guided wave fields at different radii of polar coordinates are derived in the frequency domain. The defect spot is focused when the sound field is calculated at the radius of the defect. Numerical and experimental validations are performed for the defect inspection in an iron plate. The angular bandwidth of the defect spot is used as an index for the angular resolution. The results of the proposed method show significant improvement compared to those obtained by the B-scan method, and it is found to be superior to the conventional method—named delay and sum (DAS)—in both angular resolution and calculation efficiency.

A techno-economic probabilistic approach to superheater lifetime determination

2006 ◽  
Vol 17 (1) ◽  
pp. 66-71
Author(s):  
M Jaeger ◽  
H Benhaim ◽  
D Tzidony ◽  
A Dumai ◽  
T Itai
Keyword(s):  
Life Cycle ◽  
Wall Thickness ◽  
Life Cycle Cost ◽  
Evaluation Model ◽  
Probabilistic Approach ◽  
Probability Of Failure ◽  
Operating Conditions ◽  
Time To Failure ◽  
Average Life ◽  
Failure Evaluation

In the commonly used approach, the lifetime of a superheater is estimated by characteristic values of the production parameters and the operating conditions. In this approach, a lower bound for a superheater lifetime is based on some arbitrary safety factor that does not necessarily reflect real life, where unexpected failures do occur. The method proposed here suggests coping with this reality, by employing a techno-economic probabilistic approach. It comprises the following two models: • A probabilistic time to failure evaluation model that considers the variability of the lifetime determining parameters. • A model to optimise values of technical parameters and operating conditions and to determine a superheater’s optimal replacement policy, based on life cycle cost considerations. The proposed probabilistic time to failure evaluation model can help to identify the most influential parameters for planning for a minimal probability of failure. It is applied to a unique problematic steel T22 superheater of rather specific parameters: corrosion rate, the Larson Miller Parameter (LMP), diameter and wall thickness. Sensitivity analysis has shown that the dominant factor affecting variation in superheater lifetime is the variation in the LMP, while the effect of the other parameters is quite marginal. Decreasing the standard deviation of the LMP (by keeping a more uniform material) lowered the probability of failure. This resulted in a practical recommendation to perform periodical checks of the parameter wall thickness. We also tested the effect of changing the nominal values of these parameters on the lifetime distribution. Hence, we suggest that the selection of the nominal values should be based on life cycle cost considerations; and propose a model to calculate, for any given combination, the average life cycle cost. The latter model, the optimal parameters combination model, optimises the combination of changes in all the superheater’s parameters by minimising the average life cycle cost associated with the superheater. Demonstrating the usefulness of the proposed approach, in a problematic case, suggests that it can be beneficially employed in the more general case whenever the planned lifetime of a design is threatened.

Experiment Studies on Wavelet-Based Damage Detection for Pipeline Using Ultrasonic Guided Wave

2012 ◽  
Vol 220-223 ◽  
pp. 1552-1558
Author(s):  
Wei Wei Zhang ◽  
Jing Wu ◽  
Zi Long Zhao ◽  
Hong Wei Ma
Keyword(s):  
Theoretical Prediction ◽  
Piezoelectric Ceramic ◽  
Pipe Wall ◽  
Crack Size ◽  
Guided Wave ◽  
Inspection Method ◽  
Pipeline Inspection ◽  
Ultrasonic Guided Wave ◽  
Testing Signal ◽  
Good Agreement

In this paper, a wavelet-based pipeline inspection method was illustrated experimentally. Piezoelectric ceramic (PZT5), as sensors, was used to generate and receive the guided wave signal. To be specific, a piezoelectric ring was an excitation sensor in order to generate L(0,2) mode guided wave and 16 evenly distributed piezoelectric patches in pipe circle were the reception sensors. A transverse artificial notch in the pipe wall could be detected successfully by the guided wave. For reducing the noise from the testing signal, a wavelet-based denoise technique was proposed Based on the denoised signal, both location and size of the defect could be identified. The result shows that the crack size identification was in good agreement with the theoretical prediction.

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