WO1999039355A1 - Method for determining average wall thickness for pipes and tubes using guided waves - Google Patents
Method for determining average wall thickness for pipes and tubes using guided waves Download PDFInfo
- Publication number
- WO1999039355A1 WO1999039355A1 PCT/US1999/002072 US9902072W WO9939355A1 WO 1999039355 A1 WO1999039355 A1 WO 1999039355A1 US 9902072 W US9902072 W US 9902072W WO 9939355 A1 WO9939355 A1 WO 9939355A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- pipe
- frequency
- cut
- return signal
- interrogating
- Prior art date
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/22—Details, e.g. general constructional or apparatus details
- G01N29/24—Probes
- G01N29/2412—Probes using the magnetostrictive properties of the material to be examined, e.g. electromagnetic acoustic transducers [EMAT]
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B17/00—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations
- G01B17/02—Measuring arrangements characterised by the use of infrasonic, sonic or ultrasonic vibrations for measuring thickness
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/34—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor
- G01N29/348—Generating the ultrasonic, sonic or infrasonic waves, e.g. electronic circuits specially adapted therefor with frequency characteristics, e.g. single frequency signals, chirp signals
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/46—Processing the detected response signal, e.g. electronic circuits specially adapted therefor by spectral analysis, e.g. Fourier analysis or wavelet analysis
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
- G01N29/44—Processing the detected response signal, e.g. electronic circuits specially adapted therefor
- G01N29/50—Processing the detected response signal, e.g. electronic circuits specially adapted therefor using auto-correlation techniques or cross-correlation techniques
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/02—Indexing codes associated with the analysed material
- G01N2291/028—Material parameters
- G01N2291/02854—Length, thickness
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/04—Wave modes and trajectories
- G01N2291/042—Wave modes
- G01N2291/0421—Longitudinal waves
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/10—Number of transducers
- G01N2291/101—Number of transducers one transducer
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2291/00—Indexing codes associated with group G01N29/00
- G01N2291/26—Scanned objects
- G01N2291/263—Surfaces
- G01N2291/2636—Surfaces cylindrical from inside
Definitions
- the present invention relates generally to methods for the non-destructive evaluation of the condition of pipes, tubes, cylindrical shells and the like. More specifically, the present invention relates to a method for determining the mean radius of a pipe or tube using guided mechanical waves from a single location on the tubular wall structure. 2. DESCRIPTION OF THE RELATED ART Many industrial structures, frames, conduits, flow columns and the like, are constructed in cylindrical configurations that are often difficult to access.
- NDE non-destructive evaluation
- Heat exchangers are good examples of structural environments where the entire length of a pipe or tube that requires inspection is not accessible. These structures typically involve tube sheets that incorporate sometimes hundreds of U-shaped lengths of tubing. This makes both the interior and exterior walls of the tubing difficult to access for inspection purposes. In many instances the only access points are the terminals of the tubing that are presented at the surface of the tube sheet. It would be difficult to carry out any type of progressive inspection technique in such a structural environment. In addition to problems with accessibility, progressive inspection techniques often result in large quantities of data that must first be analyzed to determine discrete wall thickness values for a range of locations in the pipe wall.
- an average wall thickness is the desired quantity for determining the remaining service life of a pipe or tube system. Taking a range of values for discrete locations within a pipe or tube and then averaging those values to obtain a quantity for the entire pipe or tube becomes a burdensome task when it is only an average value that is desired from the start.
- ultrasonic waves and/or magnetostrictively induced mechanical waves can be used to inspect the pipe or tube wall for a determination of the average wall thickness.
- the types of waves most suitable for an inspection down the length of a target tube are those that propagate longitudinally through the walls using the walls as a wave guide.
- these waves could be generated from a single location and could be analyzed from the same or a nearby location, then the goal of acquiring information on the average wall thickness could be more easily achieved.
- the present invention provides a method for determining the average wall thickness, or the mean radius of a pipe or tube, using guided ultrasonic and/or magnetostrictive wave probes by analyzing the behavior of waves traveling in the tube wall.
- the method of the present invention examines certain longitudinal wave propagation modes and identifies a cut-off frequency that is characteristic for a particular wall thickness or tube radius.
- the method of the present invention permits the rapid and accurate inspection of a length of pipe or tube from a single location on the inside diameter of the tube and permits a comparison of the data gathered with similar data for the structure in its original condition. Changes in the cut-off frequency, indirectly determined by the method of the present invention, are correlated to changes in the wall thickness and/or mean radius for the cylindrical structure.
- FIG. 1 discloses in schematic form the fundamental components of an NDE inspection system appropriate for implementation of the method of the present invention.
- FIG. 2 discloses a sample plot of longitudinal wave propagation showing group velocity as a function of frequency.
- FIG. 3 is a cross-sectional diagram of a typical pipe or tube showing the mean radius and wall deterioration characteristics.
- FIG. 4 is a partial cross-sectional view of a typical heat exchanger/tube sheet system that might employ the method of the present invention. DESCRIPTION OF THE PREFERRED EMBODIMENT Reference is made first to Fig.
- Fig. 1 discloses a target pipe/tube (10) with a typical ultrasonic transducer (12) positioned in contact with the inside diameter of tube (10) .
- Transducer (12) could be any of a number of different types of mechanical wave generating transducers that might be piezoelectrically based, magnetostrictively based, or a variety of other such devices.
- Transducer (12) generates a longitudinal wave set (14) into the walls of pipe/tube (10) to which it is mechanically coupled.
- Transducer (12) likewise detects a return signal (16) resulting from the dispersion of the interrogating signal (14) into the volume of the walls of pipe/tube (10) .
- Transducer (12) is driven by transducer driver (20) which directs the frequency and amplitude of the interrogating signal and relays the return signal through transducer cable (18) .
- Driver (20) provides the return signal to signal processor (22) which amplifies and filters the signal for analysis.
- Data analyzer (24) compares the amplified return signal with stored signal characteristics for baseline geometries for the particular pipe/tube (10) under inspection. Stored baseline signal characteristics are maintained in memory device (26) and may include a number of known geometries and wall thickness structures that might be encountered.
- Signal processor (22) in the preferred embodiment of the present invention may establish a digital signal from the frequency, timing, and amplitude characteristics of the return signal from transducer driver (20) .
- data analyzer (24) may apply any of a number of well-known signal processing techniques in order to identify and quantify changes in signal propagation characteristics that are indicative of changes in wall thickness. As is described in more detail below, a variety of signal characteristics related to group velocity and frequency allow determination of changes in the cut- off frequency for the particular tubular structure under inspection. As an example, data analyzer (24) may compare the ratio of group velocities at predetermined discrete frequencies for the target pipe/tube under inspection with the baseline for that structure as is described in more detail below. Changes in this ratio are correlated to changes in the average wall thickness (or mean radius) for the pipe/tube. In this manner the extent of wall deterioration and/or the remaining service life of the pipe can be determined.
- the present invention demonstrates that the mean radius of a section of tube or pipe can be determined from a single location by analyzing the behavior of acoustic and/or mechanical waves traveling in the tube wall volume.
- This testing process referred to as Mean Radius Testing (MRT) is dependent on the dispersion properties of longitudinal, guided waves, propagating in the tube wall.
- Longitudinal mode guided waves exhibit a characteristic "cut-off" frequency for a specific tube diameter and wall thickness.
- the frequency range over which a certain wave mode can not propagate is called the "cut-off" frequency.
- the frequencies at which the cut-off behavior occur depend primarily on the mean radius of the tube or pipe.
- a dispersion curve displaying each type of propagation mode as a function of group velocity versus signal frequency.
- Fig. 2 shows an idealized dispersion curve (32) and (34) , for the L(0,1) and L(0,2) longitudinal propagation modes.
- the guided wave group velocity changes significantly as a function of frequency for specific modes.
- F c the cut-off frequency
- V the Rod velocity limit
- B the mean radius of the tube .
- the ratio of the velocity at two discrete frequencies for a tube with a given mean radius will be a constant.
- the group velocity of the dispersed signal is a function of the frequency and the wall thickness of the pipe or tube. As indicated above, changes in the group velocity can be measured in a number of different ways by analyzing the frequencies and timing of the return signal .
- the method of the present invention depends upon the establishment of base line return signal characteristics for a particular pipe or tube geometry. Any of a number of analytical methods for determining a shift in the cut-off frequency for a particular structure can then be applied to determine the mean radius of the pipe or tube under investigation. Again referring to FIG. 2, the data analysis could focus on directly determining a shift in the cut-off frequency or indirectly determining the same through an analysis of portions of the dispersion curve. An increase in the mean radius of a pipe or tube as a result of corrosion on the inside surface will, for example, produce a reduction (32a) in the cut-off frequency.
- This reduction can be exhibited by either the detection of a new value for the cut-off frequency or the detection of a greater slope to the curve at a specific frequency (38) .
- a decrease in the mean radius of a pipe or tube under inspection which is typically indicative of exterior corrosion on the pipe or tube, will result in a positive shift (32b) in the cut-off frequency that may be evidenced by a decrease in the slope at a specific frequency (38) .
- the slope of the dispersion curve may, of course, be determined by any of a number of finite ratio techniques for analyzing the signal data.
- Measuring the velocity at the same two discrete frequencies will produce a ratio different from that obtained for a tube with no mean radius changes.
- the mean radius of the tube can be calculated and from this the average wall loss can be estimated.
- FIG. 3 discloses in cross-sectional detail pipe/tube (10) having an outside diameter, an inside diameter, and a mean radius R.
- the outside diameter exhibits some areas of deterioration (52) which serve to reduce the mean radius of the tube.
- the inside diameter exhibits some areas (50) of deterioration which serves to increase the mean radius of the tube.
- the primary value of this method of measurement is that the operating condition of the tube can be determined from a single location.
- the dispersion characteristics of the guided wave can be used (by way of the above equation) to calculate the mean radius of the tube, which can then be used to estimate the remaining average wall thickness.
- FIG. 4 shows in partial cross-section the structure of a heat exchanger (56) that incorporates a tube sheet (54) positioned within an enclosing shell (58) .
- Tube sheet (54) comprises an array of U- shaped lengths of tubing (60a through 60e) .
- the function of a typical heat exchanger involves the flow of thermal energy from one medium present within shell (58) into or out of a second medium which flows within tubing (60a through 60e) .
- the inspection of these tubes (60a through 60e) can be carried out according to the method of the present invention from the single access points present on tube sheet (54) .
- a first application of the method of the present invention might involve a pitch-catch technique as is well-known in the field and is shown in FIG. 4 through the use of probe (62) .
- Probe (62) incorporates an appropriately positioned signal source and a separate discrete signal detector.
- Probe (62) injects an interrogating signal into one end of tube (60b) which signal is received back by probe (62) upon its arrival at the opposite end of tube (60b) .
- the signal will have therefore traveled the entire length of tube (60b) and will exhibit appropriate dispersion characteristics suitable for analyzing changes in the wall thickness of the tube.
- a second application of the method of the present invention is shown in FIG. 4 with probe (64) .
- Probe (64) operates according to the pulse-echo method described in conjunction with FIG.
- the return signal may be reflected by any of a number of geometric characteristics for the tube, most prominently the terminal end of tube (60d) .
- the dispersion characteristics of the signal can be detected and analyzed according to the present method in order to determine shifts in the cut-off frequency that develop over time as a result of wall deterioration. It is understood that the method of the present invention lends itself to use with a number of different NDE techniques and is not limited to the NDE system described in the preferred embodiment. Various mechanisms for generating mechanical waves within the wall of the pipe or tube are possible and readily exhibit the dispersion characteristics that the present method utilizes.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP53963999A JP2001520753A (en) | 1998-01-29 | 1999-01-29 | Method for measuring the average wall thickness of pipes and tubes using guided waves |
AU25702/99A AU2570299A (en) | 1998-01-29 | 1999-01-29 | Method for determining average wall thickness for pipes and tubes using guided waves |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/015,133 US5970434A (en) | 1998-01-29 | 1998-01-29 | Method for determining average wall thickness for pipes and tubes using guided waves |
US09/015,133 | 1998-01-29 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1999039355A1 true WO1999039355A1 (en) | 1999-08-05 |
WO1999039355A9 WO1999039355A9 (en) | 1999-10-21 |
Family
ID=21769710
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1999/002072 WO1999039355A1 (en) | 1998-01-29 | 1999-01-29 | Method for determining average wall thickness for pipes and tubes using guided waves |
Country Status (4)
Country | Link |
---|---|
US (1) | US5970434A (en) |
JP (1) | JP2001520753A (en) |
AU (1) | AU2570299A (en) |
WO (1) | WO1999039355A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018029445A1 (en) * | 2016-08-11 | 2018-02-15 | Guided Ultrasonics Ltd | Determining a thickness of a region of wall- or plate-like structure |
Families Citing this family (32)
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US6367328B1 (en) | 1999-07-12 | 2002-04-09 | Digital Wave Corporation | Noninvasive detection of corrosion, MIC, and foreign objects in fluid-filled containers using leaky guided ultrasonic waves |
US6363788B1 (en) * | 2000-06-07 | 2002-04-02 | Digital Wave Corporation | Noninvasive detection of corrosion, mic, and foreign objects in containers, using guided ultrasonic waves |
US6295677B1 (en) * | 1999-12-23 | 2001-10-02 | Southwest Research Institute | Method for inspecting liquid filled pipes using magnetostrictive sensors |
US6561032B1 (en) | 2000-05-15 | 2003-05-13 | National Research Council Of Canada | Non-destructive measurement of pipe wall thickness |
US6568271B2 (en) * | 2001-05-08 | 2003-05-27 | Halliburton Energy Services, Inc. | Guided acoustic wave sensor for pipeline build-up monitoring and characterization |
DE10230547B4 (en) * | 2002-07-05 | 2004-07-01 | Drallmesstechnik Tippelmann Gmbh | Method and device for testing a hollow body |
US20040091076A1 (en) * | 2002-11-08 | 2004-05-13 | Pacific Gas & Electric Company | Method and system for nondestructive inspection of components |
SE527898C2 (en) * | 2004-12-22 | 2006-07-04 | Astrazeneca Ab | Procedure for drug preparation |
US7328618B2 (en) * | 2005-06-21 | 2008-02-12 | National Research Council Of Canada | Non-destructive testing of pipes |
US7821258B2 (en) * | 2008-01-07 | 2010-10-26 | Ihi Southwest Technologies, Inc. | Method and system for generating and receiving torsional guided waves in a structure |
US7573261B1 (en) | 2008-06-20 | 2009-08-11 | Ihi Southwest Technologies, Inc. | Method and system for the generation of torsional guided waves using a ferromagnetic strip sensor |
JP2010025555A (en) * | 2008-07-15 | 2010-02-04 | Daikure Co Ltd | Method and device for measuring wall thickness of high temperature vessel |
AU2009279337B2 (en) * | 2008-08-05 | 2014-07-10 | Pure Technologies Ltd. | Device and method to assess impairment of pipeline wall strength |
CA2766850C (en) | 2010-06-16 | 2020-08-11 | Mueller International, Llc | Infrastructure monitoring devices, systems, and methods |
US9328606B2 (en) | 2011-01-06 | 2016-05-03 | Schlumberger Technology Corporation | Method and device to measure perforation tunnel dimensions |
US9772250B2 (en) | 2011-08-12 | 2017-09-26 | Mueller International, Llc | Leak detector and sensor |
US8653810B2 (en) | 2011-09-19 | 2014-02-18 | Southwest Research Institute | Flexible magnetostrictive sensor |
US9939344B2 (en) | 2012-10-26 | 2018-04-10 | Mueller International, Llc | Detecting leaks in a fluid distribution system |
US9671373B2 (en) * | 2014-03-14 | 2017-06-06 | Koch Heat Transfer Company, Lp | System and method for testing shell and tube heat exchangers for defects |
US9528903B2 (en) | 2014-10-01 | 2016-12-27 | Mueller International, Llc | Piezoelectric vibration sensor for fluid leak detection |
US10036733B2 (en) * | 2015-04-13 | 2018-07-31 | Zf Friedrichshafen Ag | Hardness verification utilizing ultrasonic velocities |
US20170081954A1 (en) * | 2015-09-23 | 2017-03-23 | Tesco Corporation | Pipe joint location detection system and method |
US10283857B2 (en) | 2016-02-12 | 2019-05-07 | Mueller International, Llc | Nozzle cap multi-band antenna assembly |
US10305178B2 (en) | 2016-02-12 | 2019-05-28 | Mueller International, Llc | Nozzle cap multi-band antenna assembly |
US11733115B2 (en) | 2018-06-08 | 2023-08-22 | Orbis Intelligent Systems, Inc. | Detection devices for determining one or more pipe conditions via at least one acoustic sensor and including connection features to connect with an insert |
CA3102778A1 (en) | 2018-06-08 | 2019-12-12 | Orbis Intelligent Systems, Inc. | Pipe sensors |
US11698314B2 (en) | 2018-06-08 | 2023-07-11 | Orbis Intelligent Systems, Inc. | Detection device for a fluid conduit or fluid dispensing device |
US10859462B2 (en) | 2018-09-04 | 2020-12-08 | Mueller International, Llc | Hydrant cap leak detector with oriented sensor |
US11342656B2 (en) | 2018-12-28 | 2022-05-24 | Mueller International, Llc | Nozzle cap encapsulated antenna system |
US11473993B2 (en) | 2019-05-31 | 2022-10-18 | Mueller International, Llc | Hydrant nozzle cap |
US11542690B2 (en) | 2020-05-14 | 2023-01-03 | Mueller International, Llc | Hydrant nozzle cap adapter |
CN113466551B (en) * | 2021-05-20 | 2024-03-19 | 河北大唐国际王滩发电有限责任公司 | Cut-off frequency measurement-based method for rapidly evaluating aging degree of boiler tube |
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US5092176A (en) * | 1990-06-29 | 1992-03-03 | The Babcock & Wilcox Company | Method for determining deposit buildup |
US5418823A (en) * | 1994-01-04 | 1995-05-23 | General Electric Company | Combined ultrasonic and eddy-current method and apparatus for non-destructive testing of tubular objects to determine thickness of metallic linings or coatings |
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US4037465A (en) * | 1976-11-19 | 1977-07-26 | The United States Of America As Represented By The United States Energy Research And Development Administration | Ultrasonic probe system for the bore-side inspection of tubes and welds therein |
US4265025A (en) * | 1978-11-08 | 1981-05-05 | Westinghouse Electric Corp. | Inspection probe |
US4685334A (en) * | 1986-01-27 | 1987-08-11 | The Babcock & Wilcox Company | Method for ultrasonic detection of hydrogen damage in boiler tubes |
US4669310A (en) * | 1986-03-26 | 1987-06-02 | The Babcock & Wilcox Company | High frequency ultrasonic technique for measuring oxide scale on the inner surface of boiler tubes |
US4909080A (en) * | 1987-10-31 | 1990-03-20 | Toyoda Gosei Co., Ltd. | Ultrasonic level gauge |
-
1998
- 1998-01-29 US US09/015,133 patent/US5970434A/en not_active Expired - Lifetime
-
1999
- 1999-01-29 JP JP53963999A patent/JP2001520753A/en active Pending
- 1999-01-29 WO PCT/US1999/002072 patent/WO1999039355A1/en active Application Filing
- 1999-01-29 AU AU25702/99A patent/AU2570299A/en not_active Abandoned
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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US5092176A (en) * | 1990-06-29 | 1992-03-03 | The Babcock & Wilcox Company | Method for determining deposit buildup |
US5418823A (en) * | 1994-01-04 | 1995-05-23 | General Electric Company | Combined ultrasonic and eddy-current method and apparatus for non-destructive testing of tubular objects to determine thickness of metallic linings or coatings |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018029445A1 (en) * | 2016-08-11 | 2018-02-15 | Guided Ultrasonics Ltd | Determining a thickness of a region of wall- or plate-like structure |
CN110088564A (en) * | 2016-08-11 | 2019-08-02 | 超声超音波有限公司 | The determination of the thickness in a region in wall-like or plate structure |
US11022436B2 (en) | 2016-08-11 | 2021-06-01 | Guided Ultrasonics Ltd. | Determining a thickness of a region of wall- or plate-like structure |
Also Published As
Publication number | Publication date |
---|---|
WO1999039355A9 (en) | 1999-10-21 |
AU2570299A (en) | 1999-08-16 |
US5970434A (en) | 1999-10-19 |
JP2001520753A (en) | 2001-10-30 |
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