# Pipeline & Hazardous Materials Safety Administration

Pipeline Inspection Technologies Demonstration Report



# Pipeline Safety Research & Development Program

Final

# 2 

# E XECUTIVE 

# S UMMARY

The pipeline infrastructure is a critical element in the energy delivery system across the United States. Its failure can affect bot h public health and safety direc tly and indirectly through impacts on the energy supply. The pipeline infrastructure is aging, while at the same time Research & Development (R&D) funding from th e pipeline industry to develop technologies to assure its integrity is experiencing budgeta ry constraints. Total R&D f unding is being further reduced through the elimination of progr ams resulting from restructur ing within the government and energy industry.

The Pipeline & Hazardous Materials Safety Ad ministration (PHMSA), Pipeline Safety R&D Program mission is to ensure the safe, reliable & environmentally sound operation of the nation’s pipeline transportation system. W ith passage of the Pipeline Safe ty Improvement Act (PSIA) in 2002, industry is now required to invest significan tly more capital to insp ect and maintain their systems. The PSIA requires enhanced maintenan ce programs and continuing integrity inspection of all pipelines located within “high consequence areas” where a pipeline failure could threaten public safety, property and the environment. Accord ing to the Interstate Natural Gas Association of America (INGAA) the cost to industry to im plement the PSIA in the first ten years will exceed $2 billion.

The focus of the PHMSA Pipeline Safety R&D Program is to sponsor research and development projects intended on providing near-term solutions that will improve the safety, reduce environmental impact, and enhance the reliability of the nation’s pipeline transportation system. Conducting infield technology demonstra tion test to facilitate technology transfer from government funded R&D programs strengthe ns communication and coordination with industry stakeholders

The PHMSA Pipeline Safety R&D Program role in technology development and innovation has increased with the passage of the Pi peline Safety Improvement Act of 2002 1 

# . The implementation of the Integrity Management Pr ogram for natural gas and hazardous liquids has focused efforts on proactively finding and fixing safety-related problems.

For several years the PHMSA Pi peline Safety R&D Program along with the DOE/NETL, Gas Delivery Reliability Program have funded the deve lopment of advanced in-line inspection (ILI) technologies to detect mechanic al damage, corrosion and other th reats to pipeline integrity. Several projects have matured to a stage where de monstrations of their detection capability are now warranted. During the week of January 9 th 

# , 2006, the PHMSA Pipeline Safety R&D Program and the DOE/NETL, Gas Delivery Reliab ility Program co-sponsored a demonstration of six innovative technologies.

1 

# http://www.eia.doe.gov/oil_gas/natural_gas/ana lysis_publications/ngmajorleg/pubsafety.html 

# The keys to enhanced pipeline safety are understanding the risks, focusing on the problems, imagining solutions, and applying our ingenuity—

Ted Willke.

# 3 The demonstrations were conducte d at Battelle West Jefferson’s Pipeline Simulation Facility (PSF) near Columbus, Ohio. The pipes used in the demonstration were prepared by Battelle at the PSF and each was pre-calibrated to establish ba seline defect measurements. Each technology performed a series of pipeline inspection runs to determine their capability to detect and size mechanical damage, corrosion, stress corrosion crack ing or plastic pipe defects. Overall, each technology performed well in th eir assessment category.



# B ACKGROUND

Information regarding inspection technology advan ces needs to be dissem inated and understood by many stakeholders in the pipeline industry. While research reports, review meetings and conference presentations are commonly used to disseminate information, live demonstrations can provide additional information on the current stat e and future potential of each development. Demonstrations are challenging to technology deve lopers because newly developed technologies must be sufficiently reliable to obtain results in a fixed time frame. Ther e is not the opportunity to return to the laboratory to confirm results or change parameters. While the pressure to demonstrate the best capability of their tec hnology advances is enormous, the developers understand these events are needed to bolster support for continued development. The results of demonstrations can be difficult to directly compare since each implementation can be at a different stage of development. No direct comp arisons were made in this report. At this demonstration, representatives from the pipeline industry, indu stry trade associations, and pipeline service providers were able to witness th e performance of six new technologies and interact with technology de velopers to clarify the current a nd potential capability of these new developments. The participation of these groups was an essential elemen t of the demonstration.

This is the second benchmark of emerging pi peline inspection technologies performed by Battelle for DOT PHMSA Pipeline Safety R&D Program and DOE NETL. Information on the pipe defect sets, pipe preparation, demonstrati on facility layout, and de monstration procedures from the first test can be can be found in the final report, Benchmarking Emerging Pipeline Inspection Technologies 2 

# , prepared by Battelle. The result s from the first benchmarking can be found in the Pipeline Inspection Technologi es - Demonstration Report 3



# , prepared by NETL.

Purpose

This report provides a brief summary assessment of the demonstration benchmark results. The purpose of this assessment is to help identify promising inspection technologies best suited for further development as part of an integrated teaming effort betw een robotic platform and sensor developers. This report is not intended to provi de a detailed analysis of each technology’s performance or to rate their performance rela tive to one another.

2 

# http://primis.rspa.dot.gov/matrix/FilGet.rdm?fil=718
3 

# http://www.netl.doe.gov/technologies/oilgas/publications/td/Battelle%20Inspection%20Demo%20Final%20Report_111804.pdf

# 4 The Technologies

Six innovative sensor tec hnologies were demonstrated at Batte lle’s Pipeline Simulation Facility (PSF) the week of January 9, 2006. The different technologies demonstrat ed their ability to detect pipeline corrosion, mechan ical defects, stress co rrosion cracking, or plas tic pipe defects. Additional information on each technology may be found in both Appendix B and Appendix C. The technologies were:

ORNL Shear Horizontal Electromagnetic Acoustic Transducer (EMAT) – Oak Ridge National Laboratory (ORNL) has deve loped an EMAT system that uses shear horizontal waves to detect flaws on natural gas pipelines. A wa velet-based analysis of ultrason ic sensor signals is used for detecting physical flaws (e.g., SCC, circumferentia l and axial flaws, and corrosion) in the walls of gas pipelines. Using an in-line non-contact EMAT transmitter-receiver pair, flaws can be detected on the walls of the pipe that the cu rrent magnetic flux leakage (MFL) technology has problems detecting. One EMAT is used as a tran smitter, exciting an ultrasonic impulse into the pipe wall while the second EMAT located a few inches away from the first is used as a receiving transducer. ORNL’s technol ogy is depicted in Figure 1.

Figure 1. ORNL Shear Horizontal EMAT



# GTI Remote Field Eddy Current (RFEC) – The Gas Technology Institute (GTI) has developed a RFEC inspection technique to inspect pipelines with multiple diameters, valve and bore restrictions, and tight or miter bends. This electr omagnetic technique uses a simple exciter coil that can be less than on third of the pipe diamet er and is driven by a low-frequency sinusoidal current to generate an oscillating electromagneti c field that small sensor coils can detect. The oscillating field propagates along tw o paths; a direct axial path a nd an indirect or remote path.

# 5 The direct field attenuates rapidly because the pipe acts as a waveguide that will only allow frequencies in the gigahertz range and above to propagate. It become s negligible after 2 to 3 pipe diameters. Thus after 2 to 3 pipe diameters, th e only signal left is that from the remote field, which propagates out through the pipe wall, along its exterior and then re-enters the pipe 2 to 3 pipe diameters from the exciter coil. This is exact ly what is needed for defect detection since the electromagnetic waves must now pass directly through metal loss de fect regions and other flaws. Changes from nominal values of the amplitude and phase of the remote field detect defects in the pipe wall and measure their se verity. GTI’s technology is depicted in Figure 2.

Figure 2. GTI Remote Field Eddy Current



# SwRI Remote Field Eddy Current (RFEC) – Through funding support from PHMSA/OPS, Southwest Research Institute® has developed a remote-field eddy current (RFEC) technology to be used in unpiggable lines. The SwRI RFEC tool is capable of detecting corrosion on the inside or outside pipe surface. Since a large percentage of pipelines cannot be inspected using “smart pig” techniques because of diameter restric tions, pipe bends, and valves, a concept for a collapsible excitation coil was developed but f ound unnecessary for the pipe sizes and materials of interest in this demonstration. A breadboa rd system that meets the size, power, and communication requirements for integration into the Carnegie Mellon Explorer II robot was developed and used in the demonstration test s. This system is shown in Figure 3. The demonstration system incorporates eight detectors, and data from all eight channels are acquired and processed simultaneously as the system is s canned along the pipe at speeds up to 4 inch/sec. All of the instrumentation, except for a DC power supply and a lapt op computer (used for storage of the processed data), is located on the tool. The RFEC system can expand to inspect 6- or 8-inch-diameter pipe and can retract to 4 inches to pass through obstructions. 

# Sensor Coils MUX Board Mock Explorer Module



# Drive Coil Support

# 6 Laptop Computer with CAN Bus Interface

Encoder Wheel

Electronics Sensors Excitation Coil

DC Power Supply



# Figure 3. SwRI Remote Field Eddy Current



# PNNL Ultrasonic Strain Measurement – Pacific Northwest Nati onal Laboratory (PNNL) has developed an ultrasonic sensor system capable of detecting pipeline stre ss and strain caused by mechanical damage i.e., dents and gouges. P NNL has established the relationship between residual strain and the change in ultrasonic response (shear wave birefringence) under a uniaxial load. Initial measurements on samples in both ax ial and biaxial states have shown excellent correlation between shear birefringence measurem ents. The demonstration focused on refining the methodology, particularly under circumstances when the damage is more complex than a simple uniaxial deformation. PNNL’s t echnology is depicted in Figure 4.

# 7 EMAT Sensor

Motor for

sensor rotation Springs for smooth motion past dents



# Figure 4. PNNL Ultrasonic Strain Measurement



# Rotating Permanent Magnet – Battelle is developing a rota ting permanent magnet inspection system where pairs of permanent magnets are rotated around the centra l axis. This alternative to the more common concentric coil method can be used to induce high current densities in the pipe. Along the pipe away from the magnets in either direction, the currents flow in the circumferential direction. Anomalies and wall thic kness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the current flowing in the pipe. The inspection methodology can be configur ed to pass tight restrictions and narrow openings such as plug valves. The separation be tween the magnets and the pipe wall is on the order of an inch (2.5cm). The strength of ci rcumferential current produc es signals on the order of a few gauss, which can be detected by hall effect sensors positioned between 8 and 40 inches (10 and 100 cm) away from the rotating magnets . This evolving insp ection methodology was first demonstrated in summer of 2004. Battell e’s technology is depicted in Figure 5.

# 8 Figure 5. Battelle Rotating Permanent Magnet



# Capacitive Sensor for Polyethylene Pipe Inspection – The National Energy Technology Laboratory (NETL) has developed a capacitive probe to resolve defects in plastic natural gas pipelines. This new technology us es a non-destructive and non-haza rdous projected electric field to map voids and other anomalies. The probe can function autonomously and is intended for use in conjunction with existing “pigs” or on its ow n platform. NETL’s tech nology is depicted in Figure 6.

Figure 6. NETL Capacitive Sensor

# 9 Demonstration Configuration

The emerging inspection technologies were test ed within a 40 by 100 foot high-bay area at Battelle’s PSF. Pipes selected for these tests had various types of natural and machined defects. A black tarp and bubble wrap cove red the pipes to hide defect locations. Figure 7 shows the configuration of the pipe s during the demonstration. These pipes included:

Figure 7. High-bay Looking North



# Detection of Metal Loss

• One 8-inch diameter ERW seam welded pipe measuring 30-feet in length (0.188 inch wall thickness). The pipe sample contained two ro ws of simulated corrosion defects spaced 180° apart.

• One 8-inch diameter ERW seam welded pipe measuring 35-feet in length (0.188 inch wall thickness). The pipe sample contained two ro ws of simulated corrosion defects spaced 180° apart. This sample also included a 5-foot section of natural corrosion from a pipe pulled from service.

• One 8-inch diameter ERW seam welded pipe measuring 40-feet in length (0.188 inch wall thickness). The pipe sample contained two ro ws of simulated corrosion defects spaced 180° apart.

# 10 Detection of Mechanical Damage

• One 24-inch diameter pipe measuring approxi mately 28-feet in le ngth (0.292 inch wall thickness) comprised of two separate pipes welded together with mechanical damage defects. Three rows of mechanical damage defects were located on this pipe sample spaced 120° apart but only one row with track hoe de fects were used in the benchmarking.

• One 24-inch diameter pipe measuring approxi mately 40 feet in length (0.292 inch wall thickness) with plain (or smooth) dent defects along one row.

Detection of Stress Corrosion Cracking (SCC)

• One 26-inch diameter pipe measuring approxi mately 26 feet in length (0.281 inch wall thickness) with natural stress corrosion cracking. A separate 26-inch diameter SCC pipe sample was provided for calibration.

Detection of Plastic Pipe Defects

• One 6-inch diameter polyethylene pipe measur ing 13 feet in length ( 0.5 inch wall thickness) with cylindrical drill holes and saw cut def ects along one row on the exterior of the pipe.

Additional information on the pipe defect sets, pipe preparation, demonstration facility layout, and demonstration procedures can be found in th e final benchmarking repor t, Pipe and Anomaly Configuration for the Phase II Benchmarking of Emerging Pipeline Inspection Technologies prepared by Battelle and included in Appendix D.



# D EMONSTRATION 

# R ESULTS

This section provides an assessment of the test da ta relative to the benchmark data developed at the Battelle Pipeline Simulation Facility (PSF). The benchmark da ta is provided as Appendix A of this document and test results for the indivi dual technologies, as pr epared and submitted by the technology developers, can be found in Appendix B.

Metal Loss Corrosion Assessment

The three corrosion assessment t echnologies were demonstrated in an 8-inch diameter pipe 4



# . This diameter was chosen to match a specific cr awler implementation, Explorer, being separately developed under NETL DOE and North east Gas Association (NGA) funding 5 

# . The untethered platform is designed to traverse pipelines rangi ng from 6 to 8 inches inside diameter. The inspection technology developers were asked to include as many of the configuration and interface requirements of this platform as practical.

Three 8-inch diameter pipes were inspected by each technology for co rrosion. The first pipe (Pipe Sample 1) was a seam-welded pipe meas uring approximately 35 feet in length. This sample consisted of three pipe sections welded together (two circumferential welds) and

4 

# In the first demonstration these technologies were demonstrated in 12-inch diameter pipe.
5 

# http://www.netl.doe.gov/technologies/oil- gas/publications/td/41155_Final.PDF

# 11 contained simulated corrosion defects set along two test lines 180° apart. The simulated corrosion was created using electrochemical etchi ng techniques, an example of which is shown in Figure 8. A 5 foot section of Pipe Sample 1 also containe d natural corrosion from a pipe recently pulled from service.

Figure 8. Example Simulated Corrosion Defect using Electrochemical Etching Techniques



# The donated natural corrosion pipe sample had a fi eld girth weld with corrosion on both sides of the weld. The weld drop through was too large fo r the inspection tool speci fications and as such the pipe was trimmed to include roughly 2 feet of corrosion on one end, 3 feet of full thickness pipe at the other end, and no fi eld welds. The pipe was then sandblasted and welded between two new pipes to comprise Pipe Sample 1. Wh en the pipe was being fully characterized, an additional weld was found in the middle of the corrosi on area (see Figure 9). This weld was very fine and did not have a signifi cant crown. The natural corrosion defects were intended to be a “stretch goal” of these emerging inspection tech nologies. While the natu ral corrosion sample represents a real world problem, th is additional weld adds a complex scenario that is most likely new to the technology developers. As such, thes e search areas are reported but are not included in the results evaluation.

# 12 Figure 9. Fine, Field Weld in Natural Corrosion Pipe Segment



# The second pipe (Pipe Sample 2) was a seam-wel ded pipe measuring approximately 30 feet in length. This sample consisted of two pipe sectio ns welded together (one circumferential weld) and contained simulated corrosion defects set alo ng two test lines 180° apart. The third pipe (Pipe Sample 3) was a seam-welded pipe meas uring approximately 40 fe et in length. This sample consisted of two pipe sections welded to gether (one circumferen tial weld) and contained simulated corrosion defects along two test lines 180° apart.

All three technologies detected one false positiv e signal; however, none of the technologies had a false positive in the same locati on. None of the technologies faile d to identify a defect and were fairly accurate in predicting the locations. Thes e results are summarized in Table 1. In addition, the corrosion sizing results were plotted in a manner commonly used by pipeline inspection vendors to demonstrate commercial in-line inspec tion technology capabilities . For these graphs, benchmark data is plotted against the values re ported by the technology de velopers. Care must be taken in interpreti ng these graphs since:

• Error in the benchmark m easurements is not zero

• Only the maximum depth is compared while the corrosion pit depth varied throughout the defect; many corrosion areas had more than one area of local thinning.

• Length and width were measured at the surface ; however other measures can also be used that still accurately describe the anomaly. Overall these graphs show the results predicte d by each technology correlated well with the benchmark data. Field Weld

# 13 Table 1. Detection Rates for the Corrosion Technologies

Technology Detection Rate False Positive Rate False Negative

Rate Mean Difference in Location of Defect Standard Deviation of Defect Location SwRI – RFEC 100% (32 of 32) 3.3% (1 of 30) – Defect P2-8 called as a repeatable signal, but does not have typical flaw

signal characteristics; 0.17” deep, 1.38” long and 1.06” wide 0% (0 of 32) 0.33 1.71

GTI – RFEC 100% (32 of 32) 3.3% (1 of 30) – Defect P1-2 called as an unknown feature resembling metal loss; 0.008” deep, <1” long, and >4” wide 0% (0 of 32) 0.08 1.18

Battelle – Rotating Permanent Magnet 100% (32 of 32) 3.3% (1 of 30) – Defect P1-17 called as a small single pit 0.02” deep, 0.7” long, and 0.75” wide 0% (0 of 32) -0.31 2.05



# SwRI Results

SwRI began testing the morning of Monday, Ja nuary 9, 2006, and completed testing by mid-day Thursday, January 12, 2006. The SwRI RFEC tool acquired, processed, and displayed data in real time as it was continuously pulled through each pipe sample. Each scan took approximately 5 minutes to complete with selected higher spee d runs taking approximate ly one to two minutes to complete. A circumferential region of 60 de grees was inspected in each scan, and two scans were made along each defect line to ensure complete coverage of all defects.

The SwRI RFEC technology detection rate wa s 100%, detecting all defect sites on Pipe Sample 1, Pipe Sample 2, and Pipe Sample 3. On aver age, SwRI located anomalies slightly past the actual start of the defect location with a st andard deviation of 1.71 inches. The SwRI RFEC technology detected one false positiv e signal on Test Line 1 of Pipe Sample 2. The false positive signal was identified as a repeatable signal with out typical flaw signal characteristics with a depth of nearly 90% of the wall thickness and approximately 1 5/8 -inch in length. SwRI’s sizing accuracy is depicted in Figures 10 thr ough 12 in which the predicted and measured anomaly depths, lengths, a nd widths are presented.

# 14 Figure 10. Measured Depth vs. Predicted Depth for the SwRI RFEC

Figure 11. Measured Length vs. Predicted Length for the SwRI RFEC 0.0000 0.0188 0.0376 0.0564 0.0752 0.0940 0.1128 0.1316 0.1504 0.1692 0.18800.00000.01880.03760.05640.07520.09400.11280.13160.15040.16920.1880



# Measured Depth (inches)Predicted Depth (inches)



# 0 0.5

1 1.5

2 2.5

3 3.5

4 4.5

5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Measured Length (inches)Predicted Length (inches)

# 15 Figure 12. Measured Width vs. Predicted Width for the SwRI RFEC



# GTI Results

GTI began testing on the morning of Monday Ja nuary 9, 2006 and completed testing by the evening of Thursday January 12, 2006. The GTI RFEC sensor technology collected data by indexing through each defect region in 0.25 inch steps. The GTI RFEC technology was able to scan both test lines in each pipe sample at the same time but because of the small incremental data collection each pipe sample required a full da y to collect data. GTI did attempt a continuous scan with the results of this scan provided in Appendix C.

The GTI RFEC technology detection rate was 100%, detec ting all defect sites on Pipe Sample 1, Pipe Sample 2, and Pipe Sample 3. On average, GTI located anomalies slightly past the actual start of the defect locatio n with a standard deviati on of 1.18 inches. The GTI RFEC technology detected one false positive signal on Test Line 1 of Pipe Sample 1 but identified the anomaly as a small unknown feature with a depth of only 4% of the wall thickness and approximately 1-inch in length. GTI’s sizing accuracy is depicted in Figures 13 thr ough 15 in which the predicted and measured anomaly depths, lengths , and widths are presented. 0 0.5

1 1.5

2 2.5

3

0 0.5 1 1.5 2 2.5 3 Measured Width (inches)Predicted Width (inches)

# 16 Figure 13. Measured Depth vs. Predicted Depth for the GTI RFEC

Figure 14. Measured Length vs. Predicted Length for the GTI RFEC 0 0.5

1 1.5

2 2.5

3 3.5

4 4.5

5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Measured Length (inches)Predicted Length (inches) 

# 0.0000 0.0188 0.0376 0.0564 0.0752 0.0940 0.1128 0.1316 0.1504 0.1692 0.18800.00000.01880.03760.05640.07520.09400.11280.13160.15040.16920.1880



# Measured Depth (inches)Predicted Depth (inches)

# 17 0 0.5

1 1.5

2 2.5

3 3.5

4

0 0.5 1 1.5 2 2.5 3 3.5 4 Measured Width (inches)Predicted Width (inches)



# Figure 15. Measured Width vs. Predicted Width for the GTI RFEC



# Battelle Results

Battelle began testing the afte rnoon of Tuesday January 10, 2006 and completed testing by the afternoon of Friday January 13, 2006. Battelle’s testing was periodically interrupted due to concerns from the other corrosion inspection te chnology developers that the permanent magnet was causing interference with th eir systems. The Battelle Rotating Permanent Magnet technology was able to continuously acquire data through each pipe sample taking approximately 10 to 15 minutes to scan one test line. During the demonstrati on Battelle processed signals and displayed inspection results in real-time.

The Battelle Rotating Permanent Magnet technology detection rate was 100%, detecting all defect sites on Pipe Sample 1, Pipe Sample 2, and Pipe Sample 3. On average, Battelle located anomalies shy of the actual start of the defect lo cation with a standard deviation of 2.05 inches. The Battelle Rotating Permanent Magnet technology detected one false positive signal on Test Line 2 of Pipe Sample 1 but identified the anomal y as a small single pit with a depth of only 11% of the wall thickness and approximately 3/4-inch in length. Battelle’s sizing accuracy is depicted in Figures 16 through 18 in which the predicte d and measured anomaly depths, lengths, and widths are presented.

# 18 Figure 16. Measured Depth vs. Predicted Depth for the Battelle Rotating Permanent Magnet

0 0.5

1 1.5

2 2.5

3 3.5

4 4.5

5

0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Measured Length (inches)Predicted Length (inches)



# Figure 17. Measured Length vs. Predicted Length for the Battelle Rotating Permanent Magnet 0.0000 0.0188 0.0376 0.0564 0.0752 0.0940 0.1128 0.1316 0.1504 0.1692 0.18800.00000.01880.03760.05640.07520.09400.11280.13160.15040.16920.1880



# Measured Depth (inches)Predicted Depth (inches)

# 19 Figure 18. Measured Width vs. Predicted Width for the Battelle Rotating Permanent Magnet



# The benchmark data and test results for the three technologies that tested for metal loss on Pipe Samples 1, 2, and 3 are shown in Table 2 through Table 7. 0 0.5

1 1.5

2 2.5

3

0 0.5 1 1.5 2 2.5 3 Measured Width (inches)Predicted Width (inches)

# 20 This page intentionally blank.21Table 2. Benchmark Data vs. Results for Corrosion Pipe Sample 1; Test Line 1Simulated Corrosion Pipe Sample 1 Test Line 1Defect Number P1-1 P1-2 P1-3 P1-4 P1-5 P1-6 P1-7 P1-8 P1-9 P1-10 P1-11 P1-12Search Region (fromEnd B)328" to 340" 304" to 316" 280" to 292" 256" to 268" 232" to 244"208" to 220" 184" to 196" 160" to 172" 120" to 144" 100" to 112" 76" to 88" 52" to 64"Start and End of Defect (inches)5Benchmark DataBlankBlank287.75290.875259.625263.625232.75235.75Blank190.625192.75Blank120"140.25"BlankBlank56.7560.875SwRI –RFEC282.6285.8254.5258.7227.7231.0188.8189.7160.0172.0a=120.0122.3b=128.5129.356.960.2GTI – RFEC~311.25~314.25~281.75~285.5~260.5~264.75~232~236.5~191.25~193.75~120~134.25~56.75~60.5Battelle – RotatingPermanent Magnet288292.8260.1264.9233.2237188.8192.212013258.162.3Defect Length (inches)Benchmark DataBlankBlank3.12543Blank2.125Blank20.25BlankBlank4.125SwRI –RFEC 3.16 4.20 3.30 0.95 12a=2.25b=0.773.32GTI – RFEC < 1 2.875 3.375 3.75 1.625 14.25 2.875Battelle – RotatingPermanent Magnet3.8 3.8 2.8 2.4 12 3.2Defect Width (inches)Benchmark DataBlankBlank221Blank2BlankFull Circ.BlankBlank2SwRI –RFEC 1.25 1.95 1.09 1.92 Full Circ.a=1.82b=Full Circ.1.63GTI – RFEC > 4 1.5 ~3 > 3 1.5 >4 1.84Battelle – RotatingPermanent Magnet1.0 1.5 1.0 1.5 32 1.75Maximum Defect Depth (inches)Benchmark DataBlankBlank0.0960.0630.081Blank0.147Blank0.146BlankBlank0.122SwRI –RFEC 0.10 0.06 0.08 0.09 0.18a=0.066b=0.830.13GTI – RFEC 0.0080.0900.0640.1000.0750.070.1350.133~0.1410.1540.142Battelle – RotatingPermanent Magnet0.075 0.055 0.050 0.165Various up to0.1500.115CommentsSwRI –RFECdefect signal outsidestated regionappears to be largeregion of general wallthinning that extendsout of the designatedregion. Signal patternsnot characteristic ofcalibration defects.two defects in region,designated a and b.GTI – RFECunknown featureresembling metal loss,4%2 axially aligned pits,48% and 34%2 axially aligned pits,53% and 40%2 pits, deepest 37%.Additional featuresobserved attributed tothrough hole of defect18 sitting over drive coil2 pits offset diagonally,72% and 71%deepest pit was a singlesmall slit ~75%2 axially aligned pits,82% and 75.5%Battelle – RotatingPermanent Magnetcorrosion patch,multiple pits of differentdepthscorrosion patch,multiple pits of differentdepthscorrosion patch,multiple pits of differentdepthscorrosion patch,multiple pits of differentdepthsa slow change in signalin all sensor throughoutthe region indicates amaterial propertychangelarge area of generalcorrosion of variabledepth that spans theentire sensor width.The corrosion is closeto the weld, alteringboth signals. A largewide corrosion area at128"corrosion patch,multiple pits of differentdepths22Table 3. Benchmark Data vs. Results for Corrosion Pipe Sample 1; Test Line 2Simulated Corrosion Pipe Sample 1 Test Line 2Defect Number P1-13 P1-14 P1-15 P1-16 P1-17 P1-18 P1-19 P1-20 P1-21 P1-22 P1-23Search Region (fromEnd B)330" to 342" 306" to 318" 282" to 294" 258" to 270" 234" to 246"210" to 222" 186" to 198" 160" to 172" 120" to 144" 98" to 110" 74" to 86"Start and End of Defect (inches)Benchmark Data335.75339.625308.875312BlankBlankBlank213.625217.875BlankBlank120140.7510811079.7583.75SwRI –RFEC335.8339.9309.5312.8214.0218.1160.0172.0128.9129.7108.1110.179.981.4GTI – RFEC~336.375~340.25~309~312.75214.75218.875~120~134.25~108.5~111~79.75~83.5Battelle – RotatingPermanent Magnet334.2338.4306.9310.8241.1241.8212.5216.8126.0138.0103.1106.374.879.1Defect Length (inches)Benchmark Data3.8753.125BlankBlankBlank4.25BlankBlank20.7524SwRI –RFEC 4.04 3.314.13 12 0.79 1.99 1.48GTI – RFEC 3 2.875 3.25 14.25 1.625 2.875Battelle – RotatingPermanent Magnet3.2 2.9 0.7 3.3 12 2.2 3.3Defect Width (inches)Benchmark Data1.751BlankBlankBlank2BlankBlankFull Circ.22SwRI –RFEC 1.47 1.37 1.69 Full Circ. Full Circ. 1.82 1.72GTI – RFEC 1.75 1.5 2 > 4 1.5 2.25Battelle – RotatingPermanent Magnet1.0 1.25 0.75 2.0 > 5 1.75 1.0Maximum Defect Depth (inches)Benchmark Data0.0950.115BlankBlankBlank0.145BlankBlank0.1270.120.097SwRI –RFEC 0.08 0.110.14 0.18 0.06 0.08 0.09GTI – RFEC0.1220.0700.1130.1320.1880.1110.1130.1220.088 0.096Battelle – RotatingPermanent Magnet0.075 0.115 0.020 0.155Various up to0.1500.110 0.075CommentsSwRI –RFECappears to be largeregion of general wallthinning that extendsout of the designatedregion. Signal patternsnot characteristic ofcalibration defects.GTI – RFEC2 axially aligned pits,65% and 37%2 axially aligned pits,70% and 60%2 pits, through holeand 59%general corrosion,deepest 60% and 65%diagonal feature, 47% 51%Battelle – RotatingPermanent Magnetcorrosion patch,multiple pits of differentdepthscorrosion patch,multiple pits of differentdepthssmall single pitcorrosion patch,multiple pits of differentdepthsa slow change in signalin all sensorthroughout the regionindicates a materialproperty changearea of generalcorrosion of variabledepth that spans mostsensors. A large widecorrosion area at 128"corrosion patch,multiple pits of differentdepthscorrosion patch,multiple pits ofdifferent depths23Table 4. Benchmark Data vs. Results for Corrosion Pipe Sample 2; Test Line 1Simulated Corrosion Pipe Sample 2 Test Line 1Defect Number P2-1 P2-2 P2-3 P2-4 P2-5 P2-6 P2-7 P2-8 P2-9 P2-10 P2-11Search Region (from End B) 294" to 306" 270" to 282" 246" to258" 222" to 234" 198" to 210" 174" to 186" 150" to 162" 126" to 138" 102" to 114" 78" to 90" 54" to 66"Start and End of Defect (inches)Benchmark DataBlankBlankBlank227.25229.375Blank180.25183.375153.125156.375Blank108.125112.2580.12584.5BlankSwRI – RFEC227.6229.8180.2183.5153.4156.7129.8131.1108.2112.380.084.3GTI – RFEC227.25229.5179.75183152.75155.75107.75111.7580.2584Battelle – Rotating Permanent Magnet228.9232.0181.1184.9153.8157.6108.6112.080.083.6Defect Length (inches)Benchmark DataBlankBlankBlank2.125Blank3.1253.25Blank4.1254.375BlankSwRI –RFEC 2.213.23 3.31 1.38 4.05 4.31GTI – RFEC 2.25 3.25 3 4 3.75Battelle – Rotating Permanent Magnet 2.1 2.8 2.8 2.4 2.6Defect Width (inches)Benchmark DataBlankBlankBlank2Blank11Blank22BlankSwRI –RFEC 1.570.99 1.18 1.06 2.14 1.88GTI – RFEC 2 1 2 1.5 2.5Battelle – Rotating Permanent Magnet 1.0 1.0 1.0 1.5 1.5Maximum Defect Depth (inches)Benchmark DataBlankBlankBlank0.079Blank0.1140.085Blank0.1580.147BlankSwRI –RFEC 0.070.11 0.04 0.17 0.16 0.13GTI – RFEC 0.037 0.073 0.026 0.142 0.188Battelle – Rotating Permanent Magnet 0.075 0.075 0.065 0.165 0.170CommentsSwRI –RFECRepeatablesignal, butdoes not havetypical flawsignalcharacteristics.GTI – RFECBattelle – Rotating Permanent MagnetCorrosionpatch, withmultiple pits ofdifferent depthsCorrosionpatch, withmultiple pits ofdifferent depthsCorrosionpatch, withmultiple pits ofdifferent depthsCorrosionpatch, withlarge multiplepits of differentdepthsCorrosionpatch, withlarge multiplepits of differentdepths24Table 5. Benchmark Data vs. Results for Corrosion Pipe Sample 2; Test Line 2Simulated Corrosion Pipe Sample 2 Test Line 2Defect Number P2-12 P2-13 P2-14 P2-15 P2-16 P2-17 P2-18 P2-19 P2-20Search Region (from End B) 246" to 258" 222" to 234" 198" to210" 174" to 186" 150" to 162" 126" to 138" 102" to 114" 78" to 90" 54" to 66"Start and End of Defect (inches)Benchmark Data248.125250.25Blank202.625205.75BlankBlank130134.125BlankBlank57.7560.875SwRI –RFEC248.1249.8202.3205.4129.1133.256.359.7GTI – RFEC249251201204129.5133.557.560.5Battelle – Rotating Permanent Magnet250.0253.0204.9209.0132.8137.459.463.2Defect Length (inches)Benchmark Data2.125Blank3.125BlankBlank4.125BlankBlank3.125SwRI –RFEC 1.72 3.10 4.14 3.37GTI – RFEC 2 3 4 3Battelle – Rotating Permanent Magnet 2.0 3.1 3.6 2.8Defect Width (inches)Benchmark Data2Blank1BlankBlank2BlankBlank1SwRI –RFEC 1.21 1.21 1.69 1.25GTI – RFEC 1.5 1.5 2 1.5Battelle – Rotating Permanent Magnet 1.5 0.75 1.5 1.0Maximum Defect Depth (inches)Benchmark Data0.14Blank0.105BlankBlank0.112BlankBlank0.188SwRI –RFEC 0.11 0.08 0.11 0.16GTI – RFEC 0.148 0.081 0.159 0.176Battelle – Rotating Permanent Magnet 0.115 0.075 0.105 0.180CommentsSwRI –RFECGTI – RFECBattelle – Rotating Permanent MagnetCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepths, Onepit may bethrough hole25Table 6. Benchmark Data vs. Results for Corrosion Pipe Sample 3; Test Line 1Simulated Corrosion Pipe Sample 3 Test Line 1Defect Number P3-1 P3-2 P3-3 P3-4 P3-5 P3-6 P3-7 P3-8 P3-9 P3-10 P3-11Search Region (from End B) 384" to 396" 360" to 372" 330" to342" 300" to 312" 270" to 282" 222" to 234" 186" to 198" 162" to 174"138" to150"102" to 114" 66" to 78"Start and End of Defect (inches)Benchmark DataBlankBlank335337.25305.625306.375275277.25Blank189.875194Blank143.665144.335106.375109.625BlankSwRI –RFEC336.3338.5306.8307.6276.0278.3190.5194.8144.1144.8106.7109.9GTI – RFEC335337306.5307.75275.75277.75190193.5143.5144.75106109Battelle – Rotating Permanent Magnet338.0341.0307.8309.3276.4279.5187.8193.0144.2145.5108.8112.4Defect Length (inches)Benchmark DataBlankBlank2.250.752.25Blank4.125Blank0.673.25BlankSwRI –RFEC 2.19 0.782.29 4.22 0.73 3.19GTI – RFEC 2 1.25 2 3.5 1.25 3Battelle – Rotating Permanent Magnet 2.0 1.5 2.1 4.2 1.3 2.6Defect Width (inches)Benchmark DataBlankBlank20.752Blank2Blank0.671BlankSwRI –RFEC 1.8 0.881.93 1.64 0.63 1.29GTI – RFEC 1.5 1 2 2 1 2Battelle – Rotating Permanent Magnet 1.75 0.75 1.5 1.5 0.5 1.5Maximum Defect Depth (inches)Benchmark DataBlankBlank0.1330.1480.103Blank0.115Blank0.1200.156BlankSwRI –RFEC 0.09 0.110.09 0.10 0.09 0.15GTI – RFEC 0.164 0.1580.1420.1190.1730.1480.1120.1820.176Battelle – Rotating Permanent Magnet0.165 0.150 0.105 0.105 0.080 0.160CommentsSwRI –RFECGTI – RFEC Three pits Three pitsTwo pitsaxiallyalignedBattelle – Rotating Permanent MagnetCorrosionpatch, withmultiple pits ofdifferentdepthsSingle PitCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepthsSingle PitCorrosionpatch, withmultiple pits ofdifferentdepths26Table 7. Benchmark Data vs. Results for Corrosion Pipe Sample 3; Test Line 2Simulated Corrosion Pipe Sample 3 Test Line 2Defect Number P3-12 P3-13 P3-14 P3-15 P3-16 P3-17 P3-18 P3-19 P3-20 P3-21 P3-22 P3-23Search Region (from End B) 390" to 402" 356" to 368" 330" to342" 306" to 318" 282" to 294" 248" to 260" 210" to 222" 180" to 192"156" to168"126" to 138" 102" to 114" 66" to 78"Start and End of Defect (inches)Benchmark Data392.25396.375Blank335.875336.625BlankBlank250.625253.75214.5217.625185.765186.485Blank130134.125Blank69.573.625SwRI –RFEC392.5396.6336.9337.7251.6254.8215.2218.4186.4187.2130.5134.569.573.8GTI – RFEC393396335.75336.75251.25254214.5217.25185.75186.75130.25133.7570.2574Battelle – Rotating Permanent Magnet392.4397.0337.1338.0250.5254.4214.1218.1184.9186.2128.3132.765.970.6Defect Length (inches)Benchmark Data4.125Blank0.75BlankBlank3.1253.1250.72Blank4.125Blank4.125SwRI –RFEC 4.18 0.723.21 3.18 0.81 3.97 4.3GTI – RFEC 3 1 2.75 2.75 1 3.5 3.75Battelle – Rotating Permanent Magnet 3.6 0.9 2.9 3.0 1.3 3.4 3.7Defect Width (inches)Benchmark Data2Blank0.75BlankBlank110.72Blank2Blank2SwRI –RFEC 1.69 0.510.79 1.10 0.73 1.48 1.85GTI – RFEC 2.5 1 1.5 1.5 1 2 2Battelle – Rotating Permanent Magnet 1.25 0.5 1.0 1.0 0.75 1.25 1.5Maximum Defect Depth (inches)Benchmark Data0.094Blank0.154BlankBlank0.070.0910.139Blank0.103Blank0.088SwRI –RFEC 0.08 0.130.06 0.09 0.11 0.10 0.09GTI – RFEC0.1350.1020.1490.1450.0890.0660.1280.0940.1420.1240.1210.1140.1240.009Battelle – Rotating Permanent Magnet 0.065 0.105 0.085 0.080 0.105 0.085 0.055CommentsSwRI –RFECGTI – RFECTwo pitsaxially alignedThere was anincrease inamplitude inthis region. Weconcluded thatthe increase inthe field wascaused by thedrive coil beinglocated at P3-14. An actualdefect may be"buried" in thefield but it isnot obvious.Two pitsaxially alignedTwo pitsaxially alignedTwo pitsReflectionfrom defect 10Two featuresBattelle – Rotating Permanent MagnetCorrosionpatch, withmultiple pits ofdifferentdepthsSingle PitCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepthsSingle PitCorrosionpatch, withmultiple pits ofdifferentdepthsCorrosionpatch, withmultiple pits ofdifferentdepths

# 27 Mechanical Damage Assessment

Only one technology, the PNNL Ultrasonic Strain Measurement technology, was tested for assessment of mechanical damage. Two 24-inch diameter pipes were inspected by PNNL for mechanical damage. The first pipe (Pipe Sample 1) consisted of two pipes welded together with mechanical damage defects along three rows se parated by 120° and measured approximately 28- feet in length. The test line on Pipe Sample 1 consisted of mechanical damage created using a 50-ton track hoe. An example mechanical damage de fect from Pipe Sample 1 is shown in Figure 19. The second pipe (Pipe Sample 2) measured approximately 40 feet in length with plain (or smooth) dent defects along one test line. An example mechanical damage defect from Pipe Sample 2 is shown in Figure 20.

Figure 19. Example Mechanical Damage Defect from Pipe Sample 1

Figure 20. Example Mechanical Damage Defect from Pipe Sample 2

# 28 The benchmark data and test results for PNNL’s PNNL Ultrasonic Strain Measurement technology are shown in Table 8 and Table 9.

Table 8. Benchmark vs. Test Results fo r Mechanical Damage Pipe Sample 1

PIPE SAMPLE 1 Dent Severity 0 = No damage 1 = Least Severe 2 = Moderately Severe 3 = Severe 4 = Most Severe Defect Number Search Region (from End A)

Benchmark PNNL Comments

D1 64.5” 2 4 dent start at 63 .5" end at 66.5", length 3" D2 68.5” 2 2 dent start at 67" end at 70", length 3" D3 77.5” 2 1 dent start at 77 .3" end at 78.1", length 0.9"

D4 105” 2 2.5 long dent along the axis dent start at 99.9" end at 110.4", length 10.5"

D5 114” 1 2.5 long dent along the axis dent start at 113.8" end at 119.9", length 6.1"

D6 162” Not Part of Benchmark detected, damage looks as signi ficant as a 3 or 4, length approximately 6 inches long or two dents approximately 2 inches long separated by 1 inch

195.5” damage detected; damage looks as significant as a 3, (1 defect approximately 7 inches l ong or 2 defects, one 4 inches long and a second 2 inches long separated by approximately 1 inch) D7 230” 2 3 dent start at 228.1" end at 234.7", length 6.7" D8 240” 1 2 dent start at 236. 4" end at 242.1 length 5.7" D9 246” 1 0.5 dent start at 245. 7" end at 246.2", length 0.5"

D10 267.5” 4 4 similar to calibration defects d ent start at 264" end at 270.1", length 6.1"

D11 274” 2 4 similar to calibration defects dent start at 271" end at 276.1 length 5.1"

D12 280.5” 3 4 similar to calibration defect s dent start at 277.3" end at 282.6", length 5.3" D13 305.5” 4 NR out of scan range D14 310” 4 NR out of scan range D15 313” 3 NR out of scan range

# 29 Table 9. Benchmark vs. Test Results fo r Mechanical Damage Pipe Sample 2

PIPE SAMPLE 2 Dent Severity 0 = No damage 1 = Least Severe 2 = Moderately Severe 3 = Most Severe Defect Number Search Region (from End A)

Benchmark PNNL Comments

R03 109.25" 1 1 small degree of damage, start of dent 107" end 110" length 3"

R04 144” 3 2 moderate damage, start of dent 140.25" end 147.5", length 7.25"

R05 183” 2 3 significant damage, start of dent 178.75" end 187.25, length 8.5

R06 217” 1 1 small degree of localized dam age, start of dent 215.5" end 220, length 4.5" R07 253” 2 2 moderate damage, start of dent 250.5" end 258.5, length 8"

R08 289.5” 3 3 significant damage, start of dent 286.75 end 295.25, length 8.5" R09 325” 2 2 moderate damage, start of dent 323" end 331", length 8" R10 360.5” 3 3 significant damage, star t of dent 359" end 367", length 8" R11 397” 0 0 no dent



# The term “dent severity” is used in this report to describe relative seve rity of dents within a specific pipe sample. The absolu te severity of each dent is no t known. Determining the severity of mechanical damage is difficult since there ar e no standards such as those used for corrosion anomalies. The criteria used to establish th e benchmark severity ra tings could differ from PNNL’s severity criteria and as such ma y have led to the discrepancies.

PNNL began testing the afternoon of Monday January 10, 2006 and completed testing by the afternoon of Friday January 13, 2006. The PNNL U ltrasonic Strain Measurement t echnology only assesses the relative severity of mechanical damage defects. Location of dents is more practically performed by caliper tools and as such was not part of the evaluation criteria for this technology. Additionally, because PNNL was only requir ed to identify dent severity at a specific location the scan speed was also not assessed.

PNNL’s technology performed well on the mechanical damage sample with plain dents (Pipe Sample 2). There was discrepancy between the P NNL data and the benchmark at defect sites R04 and R05 on Pipe Sample 2; however the re maining defect locations correlated well.

There were a number of differences between the benchmark data and the PNNL data for Pipe Sample 1. PNNL noted that the multiple dents an d the non-circular nature of the pipe from the three rows of dent defects on Pipe Sample 1 created a significant amount of background deformation and thus stress and strain within the pipe sample. Due to these factors, the PNNL U ltrasonic Strain Measurement technology was not optimized for the degree of background deformation and is possibly the reason for the discrepancies between the benchmark data and PNNL’s results. PNNL indicated that additional tests would be desirable to help classify the dent severity for Pipe Sample 1.

# 30 Stress Corrosion Cracking

Only one technology, the ORNL Shear Horizontal EMAT , was tested for detection of stress corrosion cracking. ORNL began testing the afternoon of Tuesday January 10, 2006 and completed testing by mid-day Thursday January 12, 2006. The ORNL Shear Horizontal EMAT technology acquired data as thei r inspection tool was continu ously pulled through the pipe sample at the rate of about an inch per sec ond. ORNL took multiple scans through each line to assess the consistency of the sign al. Results were not displayed in real time; rather ORNL post processes the captured data to de velop final results. ORNL cl aims post processing is minimal and could easily be performed during data acquisi tion with current generation computing power.

As shown in Table 10 the technology ran three lines on a 26-inch diameter pipe with natural stress corrosion cracking. The EMAT technology detected one false positive signal on each test line. The configuration of the S CC defects could have contributed to the false positive readings. Because the EMAT configuration scans a minimum of 9-inches of the pipe’s circumference, some of the false positives could be the result of other cracks located in close proximity to the SCC defects under evaluation.

Only one defect site (SCC2) provided no discerna ble signal; however magnetic particle analysis showed that these cracks are small and difficult to detect. Additionally, the location of the crack colony listed as SCC3 is off by a couple of inch es. This is possibly due to defect (18), not considered as part of the test and located appr oximately 3-inches away in the circumferential direction, which may have been detected over the smaller SCC colony in SCC3. The most significant cracks (SCC8, SCC9, and SCC10) in th e test sample were detected by the ORNL Shear Horizontal EMAT technology. An example SCC defect is shown in Figure 21. The benchmark data and test results for ORNL’s Shear Horizontal EMAT technology are shown in Table 10.

Figure 21. Example SCC Defect

# 31 Table 10. Benchmark vs. ORNL Test Results; SCC Testing

Benchmark ORNL

Defect Number Search Region (from End B) Start of Crack Region (from End B) End of Crack Region (from End B) Type of SCC Start of Crack Region (from End B) End of Crack Region (from End B) Type of SCC

Test Line 1

SCC1 242" to 254" Blank

SCC2 (5 & 4) 226" to 242" 225.25 238.25 Isolated

SCC3

(8) 210" to 222" 209.25 212.25 Colony 214 216 Isolated

SCC4 175" to 187" Blank

SCC5 140" to 152" Blank 145 148 Colony; another isolated at 142 Test Line 2

SCC6 246" to 258" Blank

SCC7 234" to 246" Blank 236 237 Isolated

SCC8

(6) 210" to 222" 210.75 213.5 Colony 210 211 Isolated

SCC9

(7) 188" to 200" 189.25 193.5 Colony 194 196 Colony

SCC10

(9) 140" to 152" 141.5 145.5 Colony 144 149 Colony; looks like gap in the middle;

may be 2 sets separated by 1-inch. Test Line 3

SCC11

(16) 225" to 245" 224.25 241.25 Colony 237 239 Isolated; After scanning, we documented large dirt patches along line 3 We believe EMATs lifted off the surface due to dirt inside pipe. Reliability of data in

this area is low

SCC12 210" to 222" Blank

SCC13 188" to 200" Blank

SCC14 140" to 152" Blank 139 141 Isolated



# Polyethylene Pipe Defects

Only one technology, the NETL Capacitive Sensor for Polyethylene Pipe Inspection , was tested for detection of plastic pipe defects. This t echnology inspects for sma ll volumetric anomalies with an NETL specified detection threshol d of approximately 0.015 cubic inches. The measurement technology is localized and theref ore anomalies in close proximity and pipe end effects do not influence its detection capabilities.

A measure of defect significance was establishe d based on the calibration defect which was 3/8- inch in diameter and 50% deep (0.028 cubic inches). The volume of the calibration defect was set at a significance of one. The significance of all other defects was based on the volume of the

# 32 calibration defect. An example defect is shown in Figure 22. This defect was calculated to have a volume of 0.04 cubic inches which equals a si gnificance of 1.43. As shown in Table 11, the technology ran one test line on a 6-inch di ameter polyethylene pipe sample.

Figure 22. Example Plastic Pipe Defect33Table 11. Benchmark vs. NETL Test Results; Plastic Pipe TestingBenchmarkNETLDefectNumberSearchRegionDefect Locationfrom Side A (tocenter)Significance ofDefect (volumeratio fromcalibration defect)DefectVolumeDefectDiameterDefectLocation fromSide A (tocenter)Significance ofDefect (volumeratio fromcalibration defect)DefectVolumeCommentsinches inches ratioin3inches inches ratioin3D1 21" to 27" 25” 1.570.0440.375” 25.06” 1.380.039For significance: defectcalibration hole @ 18” = 1 Vol@ 18” = 0.028, Vol @ 25.06 =0.039D2 28" to 34" Blank NoneD3 35" to 41" Blank NoneD4 42" to 48" 46” 0.790.0220.25” 45.62” 0.990.028 Volume = 0.028D5 49" to 55" 53” 0.890.0251/8” wide 1”long saw cut52.55” 1.310.037 Volume = 0.037D6 56" to 62" Blank NoneD7 62" to 70" 67” 1.570.0440.375” 66.36” 1.150.033 Volume = 0.033D8 70" to 76" Blank NoneD9 77" to 83" Blank NoneD10 84" to 90" 88” 0.610.0170.25” 87.15” 0.430.012 Volume = 0.012D11 91" to 97" Blank NoneD12 98" to 104" 102” 1.430.041/8” wide 1”long saw cut101.03” 1.610.045 Volume = 0.045D13 105" to 111" 109” 1.430.040.75” 107.84” 0.710.02 Volume = 0.020D14 112" to 118" 116” 0.540.0150.375” 114.75” 0.570.16 Volume = 0.016D15 119" to 125" 123” and 123.5” 0.61 (each)0.017(each)0.25” (each) 121.89” 0.740.74 Volume = 0.021D16 126" to 132" Blank None?Indications that a consistentamount of material may havebeen removed along entirelengthD17 132" to 138" Blank None?Indications that a consistentamount of material may havebeen removed along entirelengthD18 138" to 144" 140” 1.250.0350.75” 138.3” 1.130.032 Volume = 0.032D19 144" to 150" 148” 1.110.0310.75” 146.76” 0.710.020 Volume = 0.020Not part of the benchmarking demonstration34This page intentionally blank.

# 35 While this was the second demonstration for al l other technology developers, this demonstration was the first for the NETL Capacitive Sensor technology and should be taken into consideration when evaluating the results. Du ring the demonstration, the NETL Capacitive Sensor technology collected data at a frequency of 1-hertz but has th e capability to collect data up to a frequency of 45-hertz.

NETL’s accuracy in assessing defect sever ity is depicted in Figure 23. The NETL Capacitive Sensor technology detection was excellent detecting all defect sites to within 1% of the actual centerline location and did not report any false positive signals. The percentage difference in defect significance was approximately 25%.

0.0000 0.2000 0.4000 0.6000 0.8000 1.0000 1.2000 1.4000 1.6000 1.80000.00000.20000.40000.60000.80001.00001.20001.40001.60001.8000



# Measured SignificancePredicted Significance



# Figure 23. Measured Severity vs. Predicted Severity for the NETL Capacitive Sensor



# S UMMARY

Four pipeline anomaly conditions were evaluate d by six different sensor technology developers. Three technologies assessed corrosion anoma lies while individual technologies assessed mechanical damage, SCC, and plastic pipe material loss.

The corrosion detection techniques demonstr ated significant promis e for inspection of unpiggable pipelines. Accurate de tection and sizing of natural co rrosion appears to be reachable

# 36 but additional development may be required to re fine sizing algorithms es pecially when pipe material properties are unknown and calibration defects are not availabl e. Additional data processing for some of the techno logies and collection of larger natural corrosion defect libraries to conduct repeatable testing needs to be estab lished. Future collection of data towards target corrosion on pipe samples pulled from service wi ll improve system capabili ties. In addition, the speed at which data is collected could be improve d for all of the technolog ies. The usability of these technologies will rely on their ability to collect data for long pipeline segments in a relatively short amount of time as well as their ability to meet the design and power requirements of the Explorer robotic platform.

PNNL’s mechanical damage detection techni que also achieved reasonably good results especially in the pipe sample containing only plain dents. C onsidering the uniqueness of Pipe Sample 1 (multiple dents in close proximity), more accurately assessing the dent severity for this type of pipe sample would be a future goal for PNNL’s technology. In-ser vice pipelines with the amount of denting evident on Pipe Sample 1 is highly unlikely and does no t represent a realistic pipeline operating scenario. Trac k hoe defects; however, would be typical of third party damage evident on operating pipelines.

The ORNL EMAT system also performed well de tecting natural stress corrosion cracks that formed while the pipeline was in-service. Th e ORNL EMAT technology did detect some false positives on each test line but was also able to detect the most significant SCC locations. Given the nature of SCC, it is difficult to accurately size crack depths. Some of the cracks used in the benchmarking program may have been too small to clearly detect. Collection of additional SCC defect libraries and crack sizing would be a va luable addition to this benchmarking program.

The NETL Capacitive Sensor was quite accurate in identifyi ng defect locations. Sizing of plastic pipe defects is reachable but will require additional research to develop defect sizing algorithms. While this was a successful dem onstration of the inspec tion sensor technology, inspection variables need to be c onsidered in future evaluations.

Following the submittal of their test data, the technology developers were sent the benchmark data. They were given an opportunity to co mment on their results and to provide their perspective on their technology’ s performance relative to the benchmark data. Appendix C contains the developer’s comment s. Overall, the technologies pe rformed well and the results are encouraging. As the development of these t echnologies progresses a nd future testing takes place, it is envisioned that improvements in th e technology and data analysis techniques will continue to improve the false positive rate and enhance the precision and accuracy of the defect signals.



# P ATH 

# F ORWARD

As noted, PHMSA Pipeline Safety R&D Program goals are to understand the gaps between existing technologies and those n eeded to resolve the key pipelin e issues. One recognized path forward is to integrate succe ssfully demonstrated sensor technologies into a robotic platform/sensor system that can be deployed remote ly as part of an integrated package. This effort is driven in large part by new PSIA regulations which require inspection of gas

# 37 transmission pipelines and dist ribution mains in high-consequen ce areas. A large percentage of these pipes cannot be inspected using typical “smart-pig” techniques because of diameter restrictions, pipe bends and valves . In addition, pressure differentia ls and flow can be too low to push a pig through some pipes. To help solve these problems, the PHMSA Pipeline Safety R&D Program has established an aggressive schedule to develop a prototype remote system which includes continued co-funding with industry partners. It is antic ipated that upon completion of the prototype systems, they will be able to tr averse all pipes (including unpiggable lines) of various diameters while providing continuous, real-time detection of pipe anomalies or defects.

# 38 This page intentionally blank.

# A PPENDIX 

# A – B ENCHMARK 

# D ATAA-1Calibration Metal LossLocationDepth of Metal LossMeasured Length &Width of DefectMeasured Max.Depth of DefectCommentsinches from End B tocenter of defectinches361" (59" from End A)See profileDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NBLANK 7Defect 8Defect 7NYYBLANK 10Defect 9BLANK 9P1-13 330" to 342"335.75"BLANK 6BLANK 5BLANK 1Defect 11Defect 4Defect 5BLANK 3Defect 10P1-NC2BLANK 11 (natural corrosion pipe segment)Defect 3Defect 2BLANK 2Y P1-NC1BLANK 4 (natural corrosion pipe segment)YYNYN---WELD 120"339.625" 3.875" 1.75" 0.095"P1-14 306" to 318"308.875" 312" 3.125" 1" 0.115"YNNNNYY--- ---WELD 180"P1-1 328" to 340"--- ------290.875" 3.125"---3"2.125"20.25"--- ---WELD 120"P1-22WELD 180"------ --- ------ --- N BLANK 8---4.125"---P1-11 76" to 88"--- ---2"P1-12 52" to 64"---P1-10 100" to 112"--- ---P1-15 282" to 294"--- ---P1-16 258" to 270"--- ------ --- N---P1-17 234" to 246"--- ---4.25" 2" 0.145" YP1-18 210" to 222"213.625" 217.875"--- --- --- NP1-19 186" to 198"--- ------ --- --- NP1-20 160" to 172"--- ---20.75" Full Circumference 0.127" YP1-21 120" to 144"120" 140.75"98" to 110"108" 110" 2" 2" 0.12" Y0.122"0.063"2" 0.096"1"--- ---56.75" 60.875"Defect 6P1-2 304" to 316"--- --- --- --- ---P1-5P1-3 280" to 292"287.75"P1-4 256" to 268"259.625"2" 0.147"263.625" 4" 2"0.081"Detection of Metal Loss - Page 1Sensor Design:Name:Date:Company:TEST LINE 1TEST DATA8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 34' 11.75"Pipe Sample:Defect Set:PIPE SAMPLE 1Calibration P1-1:Metal Loss Length & Widthinches2 x 2CALIBRATION DATAPIPE SAMPLE 1:Pipe Sample0.146"---P1-9 120" to 144"120" 140.25"--- ------ ---Full Circumference---P1-8P1-6 208" to 220"---P1-7 184" to 196"190.625" 192.75"160" to 172"232" to 244"232.75" 235.75"P1-23TEST LINE 274" to 86"79.75" 83.75" 4" 2" 0.097"A-2Calibration Metal LossLocationDepth of Metal LossMeasured Length &Width of DefectMeasured Max.Depth of DefectCommentsinches from End B tocenter of defectinches301.5" (58.5" from End A)See profile275" (85" from End A)See profileDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NWELD 120"YDefect 11; through holeBLANK 11BLANK 10Defect 10BLANK 9BLANK 8Defect 9BLANK 7Defect 8BLANK 1YNNNTEST LINE 2--- --- ---60.875"BLANK 3BLANK 2Defect 4BLANK 5Defect 3Defect 2Defect 1YNP2-9 102" to 114"108.125"P2-7Detection of Metal Loss - Page 2Name:Date:Company:Benchmarkingof Inspection Technologies250.25"WELD 120"BLANK 42.125" 2" 0.14"P2-12 246" to 258"248.125"P2-13 222" to 234"--- ---N--- --- ---3.125" 1" 0.105" YP2-14 198" to 210"202.625" 205.75"--- --- --- NP2-15 174" to 186"--- ------ --- --- NP2-16 150" to 162"--- ---4.125" 2" 0.112" YP2-17 126" to 138"130" 134.125"P2-18 102" to 114"--- ---P2-19 78" to 90"--- --- --- --- ---TEST LINE 1Sensor Design:--- --- ---3.125" 1" 0.188"P2-20 54" to 66"57.75"0.158"112.25" 4.125" 2"--- --- ---150" to 162"153.125" 156.375"P2-8 126" to 138"--- ---PIPE SAMPLE 2:Calibration P2-1:3 x 1Calibration P2-2:2 x 2CALIBRATION DATAPipe Sample Metal Loss Length & Widthinches3.25" 1" 0.085"0.114"3.125"YYP2-5 198" to 210"---TEST DATAPipe Sample:PIPE SAMPLE 2Defect Set:---P2-6 174" to 186"180.25" 183.375"--- ---1"--- NP2-4 222" to 234"227.25" 229.375" 2.125" 2" 0.079" YP2-3 246" to 258"--- --- --- --- --- NP2-2 270" to 282"--- --- --- --- --- NP2-11 54" to 66"--- ---P2-1 294" to 306"--- ---P2-10 78" to 90"80.125" 84.5"Defect 54.375" 2" 0.147" Y8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 30' 0.375"BLANK 6--- --- --- NA-3Calibration Metal LossLocationDepth of Metal LossMeasured Length &Width of DefectMeasured Max.Depth of DefectCommentsinches from End B tocenter of defectinches421" (59" from End A)See profileDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefect 8WELD 240"WELD 240"NYBLANK 10Defect 13BLANK 9BLANK 6Defect 12; machined defectDefect 11Defect 10BLANK 8BLANK 7BLANK 1YNYNDefect 6; machined defectBLANK 4Defect 5BLANK 3Defect 14Defect 4Defect 3; machined defectDefect 2BLANK 24.125" 2" 0.094"0.75" 0.75"P3-12 390" to 402"392.25" 396.375"0.154" N Defect 9; machined defectP3-14 330" to 342"335.875" 336.625"P3-15 306" to 318"--- --- --- --- --- N--- --- --- NP3-16 282" to 294"--- ---3.125" 1" 0.07" YP3-17 248" to 260"250.625" 253.75"3.125" 1" 0.091" YP3-18 210" to 222"214.5" 217.625"0.72" 0.72" 0.139" NP3-19 180" to 192"185.765" 186.485"--- --- --- NP3-20 156" to 168"--- ---4.125" 2" 0.103" YP3-21 126" to 138"130" 134.125"--- --- ---4.125" 2" 0.088"--- ---P3-22 102" to 114"--- ---P3-23 66" to 78"69.5" 73.625"---384" to 396"--- ---P3-11 66" to 78"TEST LINE 2--- --- --- N BLANK 5--- ------ --- --- NP3-2 360" to 372"--- ---2.25" 2" 0.133" YP3-3 330" to 342"335" 337.25"0.75" 0.75" 0.148" NP3-4 300" to 312"305.625" 306.375"2.25" 2" 0.103" YP3-5 270" to 282"275" 277.25"--- --- --- NP3-6 222" to 234"--- ---4.125" 2" 0.115" YP3-7 186" to 198"189.875" 194"--- --- --- NP3-8 162" to 174"--- ---P3-9 138" to 150"143.665" 144.335" 0.67" 0.67" 0.120" NDefect Set:8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 40' 0.25"TEST DATAPipe Sample:PIPE SAMPLE 3Benchmarkingof Inspection TechnologiesCompany:Sensor Design:P3-13 356" to 368"--- --- --- --- ---Detection of Metal Loss - Page 3Name:Date:1" 0.156"inchesPIPE SAMPLE 3:TEST LINE 1Defect 7Calibration P3-1:2 x 2P3-1CALIBRATION DATAPipe Sample Metal Loss Length & WidthP3-10 102" to 114"106.375" 109.625" 3.25"A-4This page intentionally blank.

# A-5

# A-6 This page intentionally blank.A-7A-8Pipe Sample: 993CalibrationCrackLocationLength DepthMeasuredLengthMeasuredDepthinches fromend B inches% wallthickness186.4 2.558.7 586.4 582.4 2.544.4 3DefectNumberSearch Region(Distance fromEnd B)Start of CrackRegion fromSide BEnd ofCrackRegionfrom Side Binches inches inchesIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CracksColonyof CracksIsolated CrackColonyof CracksTEST LINE 1SCC2(5 & 4)226" to 242"225.25 238.25NoneSCC1(Blank 3)242" to 254"--- ---NoneNoneBlank 1SCC3(8)210" to 222"209.25 212.25NoneSCC5(Blank 1)140" to 152"--- ---multiple cracks; max = ~1/2"multiple cracks; max = ~1/2"23Blank Area:Comments26" Diameter Pipe with Stress Corrosion Cracks; Length = 26 feetPipe Sample:Comments1multiple cracks; max = ~3/4"Defect Set:893Benchmarking of Inspection TechnologiesDetection of SCC - Page 1Sensor Design:Name:Date:Company:CALIBRATION DATATEST DATAmultiple cracks; max = ~1/4"multiple cracks; max = ~3 1/4"SCC4(Blank 2)175" to 187"--- ---NoneType of SCC45Blank 2Multiple 1/4" cracks; cracked area 2 3/4" by 2 1/2"Two isolated cracks; cracked area 4" by 1 1/2" with ~2" longcrack; cracked area 5 1/4" by 1 1/4" with ~3" long crackBlank 3A-9DefectNumberSearch Region(Distance fromEnd B)Start of CrackRegion fromSide BEnd ofCrackRegionfrom Side Binches inches inchesIsolated CrackColonyof CracksIsolated CrackColony of CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksSensor Design:Type of SCC CommentsTEST DATAPipe Sample:893TEST LINE 2None141.5 145.5NoneNoneBlankBenchmarking of Inspection TechnologiesDetection of SCC - Page 2Name:Defect Set: 26" Diameter Pipe with Stress Corrosion Cracks; Length = 26 feetDate:Company:SCC6(Blank 5)246" to 258"--- ---188" to 200"189.25 193.5SCC8(6)210" to 222"210.75 213.5NoneSCC7(Blank 4)234" to 246"---Blank---NoneMultiple cracks; max ~1/4" long; cracked area 3 1/2" by 3 1/2"Multiple cracks; max ~1/4" long; cracked area 4 1/4" by 3 3/4"Multiple cracks; max ~1/2" long; cracked area 3" by 2 1/2"SCC10(9)140" to 152"SCC9(7)A-10DefectNumberSearch Region(Distance fromEnd B)Start of CrackRegion fromSide BEnd ofCrackRegionfrom Side Binches inches inchesIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksTEST LINE 3None140" to 152"--- ---SCC13(Blank 7)188" to 200"--- ---NoneDate:Company:SCC14(Blank 6)BlankBlankBlankSCC12(Blank 8)210" to 222"--- ---NoneNoneMultiple cracks; max ~3/4" long; cracked area 17" by 1 3/4"SCC11(16)225" to 245"224.25 241.25Benchmarking of Inspection TechnologiesDetection of SCC - Page 3Name:Sensor Design:Type of SCC CommentsTEST DATAPipe Sample:893Defect Set: 26" Diameter Pipe with Stress Corrosion Cracks; Length = 26 feetA-11Calibration DefectLocationVolume of Defect Depth of Defect Diameter of Defectinches from end A cubic inches inches inchesC1: 18 0.028 0.25 0.375DefectNumberSearch Region(Distance from EndA)Location of DefectRegion from Side ASignificance of Defect(based on volume ratiofrom calibrationdefect)Volume of Defect (in3)(provided toparticipant after defectsignif reported)Depth of Defect (in)(provided to participantafter defect signif reported)Diameter of Defect(in) (provided toparticipant after defectsignif reported)Commentsinches inchesCalibration Defect =1Less Severe <1More Severe >1cubic inches inches inches----0.750.75Comments0.25----0.125----0.250.125----BLANK 0 ---- ----53" 0.89D6 56" to 62"BLANK49" to 55"D2D4 42" to 48"46"D3 35" to 41"BLANK 028" to 34"BLANK 0----D1 21" to 27"25" 1.57 0.044 0.4---- ----0.375CALIBRATION DATADefectLINE 1TEST DATA6" Diameter, 0.5" Wall Thickness Pipe Sample, ~13' in lengthPipe Sample:Pipe Parameters:PLASTIC PIPE SAMPLEBenchmarking of Inspection TechnologiesDetection of Plastic Pipe Defects - Page 1Sensor Design:Name:Date:Company:---- ----0.450.0220.20 ---- ----0.0250.79D5D7 63" to 69"67" 1.57 0.044 0.4Saw Cut ~1" long and 1/8" wideSame as D1D8 70" to 76"BLANK 0 ---- ----0.375--------D9 77" to 83"BLANK 0----D12 98" to 104"102" 1.43 0.04 0.35 Saw Cut ~0.9" long and 1/8" wideD11 91" to 97"0.04 0.09D13 105" to 111"109" 1.430.750.015 0.14D14 112" to 118"116" 0.540.3750.017 (each) 0.35 (each) Defect consists of two identical holes 1/2" apartD15 119" to 125"123" and 123.5" 0.61 (each)0.25 (each)D16 126" to 132"BLANK 0----D17 132" to 138"BLANK 0D19 144" to 150"148" 1.11D10 84" to 90"88" 0.610.031 0.070.017 0.35---- -------- ----D18 138" to 144"140" 1.25 0.035 0.08----A-12This page intentionally blank.

# A PPENDIX 

# B – D EMONSTRATION 

# T EST 

# D ATA

# B-1 

# S OUTHWEST 

# R ESEARCH 

# I NSTITUTE 

# (S W 

# RI) D EMONSTRATION 

# T EST 

# D ATA

# B-2 This page intentionally blank.B-3Calibration Metal LossLocationDepth of Metal LossMeasured Length &Width of DefectMeasured Max.Depth of DefectCommentsinches from End B tocenter of defectinches359(59 from End A)Seeprofile298.5(58.5 from End A)Seeprofile277(85 from End A)Seeprofile(59 from End A)SeeprofileDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NNo indication309.5NNNo indicationNo indicationNo indicationNo indicationNo indicationAppears to be large region of general wall thinning that extends out ofthe designated region. Signal patterns are not characteristic of thecalibration defects.No indicationNDefect type signal outside stated region.Two defects in region, designated a and b.Appears to be large region of general wall thinning that extends out ofthe designated region. Signal patterns are not characteristic of thecalibration defects.No indicationNNNWELD 120"312.8P1-13 330" to 342"335.8 339.9 4.04 1.47 0.083.31P1-14 306" to 318"1.37 0.11NNNNWELD 180"P1-1 328" to 340"0.95 1.92a=2.25, b=0.77 a=1.82, b=Full Circ.WELD 120"P1-10 100" to 112"WELD 180"Calibration P3-1:3.32P1-11 76" to 88"1.632 x 23 x 12 x 2P1-15 282" to 294"P1-16 258" to 270"No indicationP1-17 234" to 246"4.13 1.69 0.14 NP1-18 210" to 222"214.0 218.1P1-19 186" to 198"0.06 NP1-20 160" to 172"160.0 172.0 12.00 Full Circ. 0.18 NP1-21 120" to 144"128.9 129.7P1-22 98" to 110"108.1 110.10.13P1-12 52" to 64"56.9 60.2P1-2 304" to 316"0.06P1-5P1-3 280" to 292"282.6 285.8 3.16 1.25 0.101.99 1.82 0.08 N0.79 Full Circ.0.09258.7 4.20 1.951.09189.7Benchmarkingof Inspection TechnologiesDetection of Metal Loss - Page 1Sensor Design:Name:Date:Company:GaryBurkhardt27-Jan-06Southwest Research InstituteRFECTEST LINE 1TEST DATACalibration P2-1:8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 34' 11.75"Pipe Sample:Defect Set:PIPE SAMPLE 12 x 2CALIBRATION DATAPIPE SAMPLE 1:PIPE SAMPLE 3:Pipe SamplePIPE SAMPLE 2:Calibration P2-2:Calibration P1-1:Metal Loss Length & Widthinchesa=0.066, b=.08312.00P1-9 120" to 144"a=120, b=128.5 a=122.3, b=129.3Full Circ. 0.18160.0 172.0P1-8P1-6 208" to 220"P1-7 184" to 196"188.8160" to 172"232" to 244"227.7 231.00.083.30P1-4 256" to 268"254.5P1-23TEST LINE 274" to 86"79.9 81.4 1.48 1.72 0.09B-4B-5B-6This page intentionally blank.

# B-7 

# Comments on Tests Performed During Demonstration at Battelle: “Phase II Benchmarking Emerging Pipeline Inspection Technologies” January 9–13, 2006

APPLICATION OF REMOTE-FIELD ED DY CURRENT (RFEC) TESTING TO INSPECTION OF UNPIGGABLE PIPELINES

OTHER TRANSACTION AG REEMENT DTRS56-02-T-0001
SwRI ® 

# PROJECT 14.06162 PIPELINE AND HAZARDOUS MATERIA LS SAFETY ADMNISTRATION U.S. DEPARTMENT OF TRANSPORTATION

SOUTHWEST RESEARCH INSTITUTE ®



# January 2006

Demonstration tests of the remote-field eddy cu rrent (RFEC) method for inspection of 8-inch pipe were performed by Sout hwest Research Institute ® 

# (SwRI ® 

# ). The target a pplication of the inspection technology is to integrate it with th e Explorer II robot under development by Carnegie Mellon University. Therefore, the approach ta ken by SwRI was to perform the demonstration using a tool that meets the requirements and spec ifications for the Explor er II robot. All of the instrumentation (except for external power, which will be supplied by the robot), including excitation signal generation, amplification, filt ering, multiplexing, analog -to-digital conversion, and digital signal processing (to provide phase-s ensitive signal detection), was located on the RFEC tool. Total power required was less than half of the power budget available from the robot. Communication of commands and transfer of the pr ocessed signal data to an external computer were accomplished using a CAN bus—the same bus that will be used on the robot. Although the tool incorporated 8 channels (coverage of 60 degrees circumfe rentially) instead of the 48 channels intended for the robot t ool (to achieve 360 degrees covera ge), the circuitry is readily scalable to the full number of channels. Data were acquired by all 8 channels simultaneously during a single scan. The scans were made at a velocity of 1.5 inches/sec, and it was demonstrated that 4 inches/sec (the maximum scan speed of the robot) was possible. The data were post-processed for analysis to determine de fect characteristics (l ength, width, and depth) using software that is readily adaptable to field inspections
The development of hardware that meets constraint s associated with factors such as scan speed, power, and size always results in compromises that are not fact ors if, for example, laboratory instrumentation is used and if scan speeds are very slow. For example, slow scan speeds mean that significantly greater noise-reduction filtering can be used because time constants can be very long compared to those necessitated by fast scan speeds. Laboratory instrumentation can incorporate additional filtering and signal pro cessing that cannot read ily be performed by circuitry that must meet size and power cons traints. Since the SwRI tool met the robot constraints, it can be expected that results simila r to those achieved in these tests can be expected from the final integrated hardware.

# B-8 It should be noted that defect characterization has a strong subjective element. In this demonstration, we were working with a brand ne w system, looking at defect types we had not seen before. That meant we had to use our best judgment and understand ing of the RFEC method to interpret the indications. After the system has been used more extensively, experience will allow the operator to know quickly what type of defect is being detected based on the signal characteristics. The quantitative interpretation of the signals will then be improved over the present level. For example, the natural corrosion region in the de monstration pipes gave a signal unlike any of the calibration defects in our lab or supplied by Battelle. Furthermore, the signal extended beyond the designated region. As a result, we used our best judg ment and reported the wall loss indicated by our depth algorithms. Magnetic field effects or the s imple nature of RFEC response to very large area defects could cause our estimate to be in error. Familiarity with this type defect over a period of time would assure us of making a quicker and potentially more accurate appraisal of the corrosion.B-9GASTECHNOLOGYINSTITUTE(GTI)Demonstration Test DaDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal Loss Region Width of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NWELD 120"NoneNoneNoneNoneNoneNoneTEST LINE 2NoneNoneNoneNoneNoneDetection of Metal Loss - Page 2Name:Date:Company:Benchmarking of Inspection TechnologiesWELD 120"Sensor Design:P2-18 102" to 114"P2-19 78" to 90"P2-42 1.5 0.1483 1.5 0.081P2-12 246" to 258"249 251P2-13 222" to 234"P2-14 198" to 210"201 204P2-15 174" to 186"P2-16 150" to 162"4 2 0.159P2-17 126" to 138"129.5 133.53 1.5 0.176P2-20 54" to 66"57.5 60.5TEST LINE 1P2-9 102" to 114"107.750.142111.75 4 1.5P2-7 150" to 162"152.75 155.75P2-8 126" to 138"8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 30' 0.375"13 2 0.0260.0733.25P2-5 198" to 210"TEST DATAPipe Sample:PIPE SAMPLE 2Defect Set:P2-6 174" to 186"179.75 183222" to 234"227.25 229.5 2.25 2 0.037P2-3 246" to 258"P2-2 270" to 282"P2-11 54" to 66"P2-1 294" to 306"2.5 0.188P2-10 78" to 90"80.25 84 3.75B-10

# B-11 

# Analysis of Sensor Benchmarking Tests



# Remote Field Eddy Current Technique

Prepared by: Julie Maupin, Albert Teit sma, Paul Shuttleworth Gas Technology Institute 1700 S. Mount Prospect Road Des Plaines, Illinois 60018

27 January 2006

# B-12 Abstract During the week of 9 January 2006, GTI staff travelled to the Battelle Lab’s West Jefferson facility in Columbus, OH to test a prototype RFEC inspection vehicle in 3 samples of 8” pipe. We report briefly on the apparatus and its design, the electronic readout and data acquisition, and the analysis of the data. Where appropriate, we have discussed effects which lead to uncertainties in the location and size of reported defects. We also discuss uncertainties which may affect whether a defect would have been observable by our apparatus.

Introduction The remote field eddy current (RFEC) technique is an electromagnetic, through-wall inspection technique for detecting defects and wall thinning in pipe walls. A simple exciter coil can be driven with a low frequency sinusoidal current to generate an oscillating magnetic field that small sensor coils can detect. This low frequency (10’s of Hz) oscillating field will propagate via two paths. It will propagate directly down the pipe a short distance. It will also propagate out through the wall, along the exterior of the pipe, and will re-enter the pipe --- the so-called indirect field. At axial distances of 2-3 pipe diameters fr om the exciter coil, the indirect field re-entering the interior of the pipe is much larger than the direct field coming from the exciter coil. Since it passes through the pipe wall, the indirect field contains information regarding the condition of the pipe. Changes from nominal value of the am plitude and phase of the indirect field indicate defects in the wall.

Figure 1: Paths of Energy Flow in the RFEC Technique. The remote field re-entering the pipe is the one containing the information regarding the condition of the pipe wall.

We constructed a vehicle (“jig”) for carrying t he RFEC apparatus. Near its front end it carried a solenoidal exciter coil, approximately 4” in diameter and 5” in length. It was comprised of1300 windings of 26 gauge wire. The sensor coils are located at distances of approximately 17” upstream of the exciter coil. They are 3⁄4” in di ameter, 3/8” in width, and contain approximately 20K windings of 50 gauge wire. Configured on the jig as two sets of 8 sensor coils, each set covered an angle of approximately 60o circumferentially at 1⁄4” spacing.

Mechanical Design The RFEC vehicle was composed of three parts, front support, rear support, and the center body. The front and rear supports had steering mechanisms on the wheels that helped keep the device upright and prevented any major rotation of the vehicle. The supports were coupled to

# B-13 the center body, which contained all the equipment necessary to the RFEC technique. A picture of the center body is shown in Figure 2.

Figure 2: Center body of RFEC vehicle.

GTI used two sets of 8 sensor coils to measur e two defect lines simultaneously. The coils were mounted on shafts that served as pegs to attach the coils to plastic guides as shown in Figure 3. The guides were rounded to match the circumference of the pipe and routed on the leading edge to avoid jamming the welds. The guides were held against the pipe wall by spring-loaded, parallelogram configured arms. An end view of t he sensor coil mounts is shown in Figure 4.



# Sensor Coils MUX Board Mock Explorer Module



# Drive Coil Support

Plastic Coil Guide

Coil

Shaft

Figure 3: Diagram of sensor coils mounted to plastic guides.



# Direction Of Travel

# B-14 Figure 4: Sensor coil mounts inside an 8” pipe.

The drive coil has been placed between two support modules, one having been built to imitate a module on the Explorer II robot. These support modul es were important to keeping the drive coil centered in the pipe.

GTI used an automatic winch system to pull the vehicle through the pipe. A tether line was attached to the front end of the vehicle. The tether wraps once around an encoder and then is wound onto a motor. The system is mounted directly onto the pipe and is controlled by LabVIEW to move the vehicle in 1⁄4” steps.

Uncertainties Related to Mechanics The jig suffered from some rotation inside the pipe. Each coil could have experienced rotations of up to ± 10 ° . There were some encoder losses. After traveling 25’ in the pipe, we were measuring about 5” short of the actual location of the sensor coils. We eventually attached a fiberglass tape measure to the back end of the vehicle so we could always double check the encoder readings. In order to get good wall coverage from the coils, they had to be staggered, meaning half were closer to the drive coil than the other half. We have made provisions to correct the offset in the data analysis but there will still likely be an effect on the results. 

# Mounting

Spring

Plastic Coil

# B-15 Electronics and Data Acquisition (DAQ) System GTI’s embodiment of a Remote Field Eddy Curr ent inspection system is as follows: Signal Recovery 7265 DSP lock-in amplifier, Kepco BOP36-6M excitation coil driver, ADG407 16 channel multiplexer, Ni GPIB+ Gpib board and Ni PCI-6601 Counter Timer board. The preceding hardware is controlled by a Dell Pentium 4 workstation running at 2.99MHz with 1Gb of main memory and executing Lab View 7.1 under Windows XP Professional operating system. A general schematic of the DAQ system is shown in Figure 7.

Channel addressing and distance gauging is accomplished using a Ni 6601 time/counter PCI circuit board. Distance measurements are made using a relative incremental encoder having a resolution of 1/16”.

Figure 5: Schematic of DAQ System. This figur e schematically shows a 4-channel system. The system we operated at Battelle was a 16-channel version of this schematic.

GTI’s RFEC machine is using a 100 count per revolution quadrature encoder. The encoder is interfaced to the system using a National Inst rument PCI-6601 counter/timer circuit board. This circuit board supports 5 encoders; the encoder interface is done in hardware. The counter chip used in the NI circuit board has 32 bit registers giving a counting range of 268,435,453 inch.

Data Collection Three LabView programs were used to collect data from the instrumentation on the jig. One read the encoder, one controlled the motor, and the other controlled the lock-in amplifier and acquired data from the coils. Acquiring the phase angle and magnitude of each coil was achieved by using a sequence of binary addressing to the multiplexer board. The program cycles through each coil sequentially. Once the data has been acquired for all 16 coil channels, the motor program fires the motor until the encoder program realizes it has traveled to the next 1⁄4” step. Once the motor stops, the coils are again read and the phase and magnitude data is recorded to Excel. The process repeats.

The lock-in amplifier has a programmable time constant for the low pass filter at its output. The program was written so that the operator could set the number of time constants that the program would wait at each coil address. Having a wait of multiple time constants ensured that

# B-16 unsettled data would be flushed out and the readings would be accurate. The drawback to waiting for a certain number of time constants is slower acquisition time. It takes a significantly longer time to obtain data for 16 coils making ov erall inspection speed slow. No problems were encountered with LabVIEW.

Analysis

Pipe Sample 3 Analysis of defect depth on Pipe Sample 3 was primarily done using Russell NDE Systems Inc.’s Adept Pro program. This program is the result of decades of research and focuses on the Voltage Plane for analysis. The display produced by the program is shown for Defect Line1 in Figure 6.

# B-17 Figure 6: Adept Pro display of Defect Line 1 from Pipe Sample 3.



# Weld Defects φ

# B-18 The display shows a strip chart of the phase angle on the left, followed by a C-Scan of the phase. Although the C-Scan provides a good overview of the defects, often as in this case, thestrip chart is better for seeing the smaller defects. The magnitude information (strip chart and Cscan) is displayed to the right of the phase information. The top right hand panel shows the Voltage Plane. The black spiral is the attenuation spiral: as the wall thickness increases, the remote filed eddy current signal strength decreases while the phase also decreases, resulting in a spiral polar plot. The blue curve on the plot is the signal from the defect at the horizontal marker that runs across the strip charts and C-scans. The two red lines on either side of the marker delimit the range of data analyzed.

If the blue line is extended to intersect the wall-thinning spiral, the vector from the origin of the polar plot to the intersection point makes an angle φ with the x-axis. Angle φ is used to determine the depth of the defect. The length of the blue line is used to find the circumferential extent of the defect. As in Figure 6, Figure 7 shows the analysis of Line 2 of Pipe 3.

# B-19 Figure 9: Adept Pro Display of Defect Line 2.

Adept Pro’s function is primarily to determine defect depth. Defect length and width are best obtained from axial and circumferential scans across the defect. Remote field eddy current signals spread in both the axial and the circumferential directions. To get length and width 

# Weld Defects

# B-20 requires corrections for the spread. Axial lengths estimated from the data should be reasonable. However, the combination of much greater spread in the circumferential direction combined with sensor separation means circumferential precision is poor.

Pipe 2 was analyzed with an internally written MATLAB program. The fundamental equations are the same as used by Russell‘s Adept Pro software but there are some differences in the calibration. This can lead to small differences in the results for this pipe. This approach was used because Pipe 2 has two calibration defects with different depths. We expect the new calibration to give better results over a wide range of defect depths.

# B-21 Table 1: C-scan Plots of defects found on Pipe 3 Test Line 1.

P3-10 P3-09

P3-07 P3-05

P3-04 P3-03

# B-22 Table 2: Line 1 Defects Defect

Location Max Depth (% of wall thick.) Defect Length Defect

Width

106” 96% 3” 2”

143.5” 78% 1.25” 1”

190” 92% 3.5” 2”

275.75” 75% 2” 2”

306.5” 84% 1.25” 1”

335” 87% 2” 1.5”

C-Scan plots The C-scan plots for all found defects are attached as a separate document. The tables containing Pipe 1 defects show the strip chart and C-scan for the phase only. The tables containing Pipe 2 defects show the C-scan for the phase only. Finally, the tables containing Pipe 3 defect information show the strip chart and C-scan for both the phase and magnitude.

Summary Results Table The Excel spreadsheet summarizing the results is attached as a separate document. Pipe 2 data was only analyzed for the deepest pit. Data from Pipes 1 and 3 that showed dual pits are recorded in the spreadsheet as two measurements representing the maximum depth of each pit.

# B-23 Table 1: C-scan Plots of defects found on Pipe 1 Test Line 1.

P1-12 P1-09

P1-07 P1-05

P1-04 P1-03

# B-24 P1-02

# B-25 Table 2: C-scan Plots of defects found on Pipe 1 Test Line 2.

P1-23 P1-22

P1-21 P1-18

P1-14 P1-13

# B-26 Table 3: C-scan Plots of defects found on Pipe 2 Test Line 1.

P2-10 P2-09

P2-07 P2-06

P2-04

# B-27 Table 4: C-scan Plots of defects found on Pipe 2 Test Line 2.

P2-20 P2-17

P2-14 P2-12

# B-28 Table 5: C-scan Plots of defects found on Pipe 3 Test Line 1.

P3-10 P3-09

P3-07 P3-05

P3-04 P3-03

# B-29 Table 6: C-scan Plots of defects found on Pipe 3 Test Line 2.

P3-23 P3-21

P3-19 P3-18

P3-17 P3-14

# B-30 P3-12

# B-31 

# B ATTELLE 

# D EMONSTRATION 

# T EST 

# D ATA

# B-32 This page intentionally blank.B-33DefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal LossRegionWidth of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/NDefectNumberSearch Region(Distance from End B)Start of Metal Loss Regionfrom Side BEnd of Metal Loss Regionfrom Side BTotal Length of Metal LossRegionWidth of Metal Loss RegionMaximum Depth ofMetal Loss RegionAdditional DataAttached?Commentsinches inches inches inches inches inches Y/N184" to 196"160" to 172"188.8192.2TEST LINE 1TEST DATA8" Diameter, 0.188" Wall Thickness Pipe Sample; Schedule 10; Length = 34' 11.75"Pipe Sample:Defect Set:PIPE SAMPLE 1Benchmarking of Inspection TechnologiesDetection of Metal Loss - Page 1Sensor Design:Name:Date:Company:Bruce NestlerothJanuary 26,2006BattelleRotatingPermanent Magnet EddyCurrent Inspection System0.1100.050Various depths up to0.150 inchesTEST LINE 21.00.075Greater than 5 inches0.1651.51.00.075120" to 144"P1-1 328" to 340"1.01.75P1-4 256" to 268"P1-23 74" to 86"103.1106.3P1-3 280" to 292"Corrosion patch, with multiple pits of different depthsP1-2 304" to 316"0.055P1-50.115Various depths up to0.150 inchesNo Metal Loss DetectedYes. Raw Signals12.0126.0138.0No Metal Loss DetectedNo Metal Loss DetectedP1-12 52" to 64"P1-22 98" to 110"P1-9 120" to 144"P1-8P1-6 208" to 220"P1-7No Metal Loss DetectedYes. Raw SignalsYes. Raw SignalsP1-18 210" to 222"2.00.155Yes. Raw Signals212.5216.83.30.750.020Yes. Raw SignalsP1-17 234" to 246"Yes. Raw SignalsP1-16 258" to 270"No Metal Loss DetectedP1-11 76" to 88"No Metal Loss Detected1.7558.162.33.2WELD 180"1.250.115Corrosion patch, with multiple pits of different depthsSmall single pitP1-10 100" to 112"P1-20 160" to 172"No Metal Loss Detected12.032.01.52.42.2No Metal Loss Detected120.0132.0No Metal Loss DetectedYes. Raw SignalsYes. Raw SignalsYes. Raw SignalsYes. Raw SignalsP1-13Yes. Raw SignalsYes. Raw SignalsYes. Raw SignalsYes. Raw SignalsWELD 120"P1-14 306" to 318"WELD 180"232" to 244"P1-15 282" to 294"P1-19 186" to 198"P1-21WELD 120"Corrosion patch, with multiple pits of different depthsYes. Raw SignalsYes. Raw SignalsYes. Raw SignalsYes. Raw SignalsCorrosion patch, with multiple pits of different depthsA area of general corrosion of variable depth that spans most sensors.A large wide corrosion area at 128".A slow change in signal in all sensors throughout the region indicates amaterial property changeYes. Raw SignalsYes. Raw SignalsCorrosion patch, with multiple pits of different depthsCorrosion patch, with multiple pits of different depthsCorrosion patch, with multiple pits of different depthsCorrosion patch, with multiple pits of different depthsA large area ofgeneral corrosion of variable depth that spans the entire sensor width. Thecorrosion is close to the weld, altering both signals. A large wide corrosion area at 128"A slow change in signal in all sensors throughout the region indicates amaterial property changeYes. Raw SignalsYes. Raw SignalsYes. Raw Signals334.2338.43.2330" to 342"1.00.075Corrosion patch, with multiple pits of different depthsCorrosion patch, with multiple pits of different depths233.2237.02.8260.1264.93.8288.0292.83.874.879.13.3241.1241.80.7306.9310.82.9No Metal Loss DetectedB-34B-35B-36This page intentionally blank.

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 1 

# Pipe 1

Raw data output on same scale 420 inches, 2 welds @ 120 and 180 inches

Search Region Extra data for noise assessment Extra data for noise assessment348354360366372 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Cal 1-1 Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 2322328334340346



# P1-1 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors298304310316322



# P1-2 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 3 P1-3274280286292298 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P1-4250256262268274 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 4 P1-5226232238244250 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P1-6202208214220226 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 5 P1-7178184190196202 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal



# P1-8 Distance (inches)Sensor Output154160166172178 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors 

### Weld Signal

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 6 P1-9 note reporting area larger, 120 to 144 inches114120126132138144150 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P1-1094100106112118 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 7 P1-117076828894 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P1-124652586470 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 8324330336342348



# P1-13 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors300306312318324



# P1-14 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 9276282288294300



# P1-15 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors252258264270276



# P1-16 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 10228234240246252



# P1-17 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors204210216222228



# P1-18 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 11180186192198204



# P1-19 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors154160166172178



# P1-20 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 12114120126132138144150



# P1-21 note reporting area larger, 120 to 144 inches Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal9298104110116



# P1-22 Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 1 - Page 136874808692 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P1-23

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 1 

# Pipe 2

Raw data output on same scale 360 inches,1 weld @120 inches

Search Region Extra data for noise assessment Extra data for noise assessment



# Cal 2-1292298304310 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 2 Cal 2-2264270276282288 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-1288294300306312 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 3 P2-2264270276282288 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-3240246252258264 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 4 P2-4216222228234240 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-5192198204210216 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 5 P2-6168174180186192 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-7144150156162168 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 6 P2-8120126132138144 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal



# P2-Weld108114120126132 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### P2-9 Signal

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 7 P2-996102108114120 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-107278849096 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 8 P2-114854606672 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-12240246252258264 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 9 P2-13216222228234240 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-14192198204210216 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 10 P2-15168174180186192 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-16144150156162168 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 11 P2-17120126132138144 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



### Weld Signal



# P2-1896102108114120 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 2 - Page 12 P2-197278849096 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# P2-204854606672 

# Distance (inches)Sensor Output CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 1 

# Pipe 3

Raw data output on same scale 480 inches, 1 weld @ 240 inches

Search Region Extra data for noise assessment Extra data for noise assessment



# Cal 3-1409415421427433 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 2 P3-1378384390396402 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-2354360366372378 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 3 P3-3324330336342348 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-4294300306312318 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 4 P3-5264270276282288 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-Weld228234240246252 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 5 P3-6216222228234240 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-7180186192198204 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 6 P3-8156162168174180 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-9132138144150156 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 7 P3-1096102108114120 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-116066727884 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 0 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 8 P3-12384390396402408 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-13350356362368374 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 9 P3-14324330336342348 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-15300306312318324 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 10 P3-16276282288294300 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-17242248254260266 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 11 P3-Weld228234240246252 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-18204210216222228 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 12 P3-19174180186192198 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-20150156162168174 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 13 P3-21120126132138144 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output



# P3-2296102108114120 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# Battelle – Rotating Magnetic Field Inspection January 2006 Pipe 3 - Page 14 P3-236066727884 CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5

CCW 2.5” CCW 2” CCW 1.5” CCW 1” CCW 0.5” 180 deg CW 0.5” CW 1” CW1.5” CW 2” CW 2.5Axial SensorsRadial Sensors



# Distance (inches)Sensor Output

# B-76 This page intentionally blank.

# B-77 

# P ACIFIC 

# N ORTHWEST 

# N ATIONAL 

# L ABORATORY 

# (PNNL) D EMONSTRATION 

# T EST 

# D ATA

# B-78 This page intentionally blank.

# B-79

# B-80 This page intentionally blank.B-81B-820102030405060700 50 100 150 200 250 300 350 400 450Distance (inches)

Ultrasonic Amplitud e-0.100.000.100.200.300.400.50 Ultrasonic thickness independent measurementAmplitude2Cylindrical1Spherical1Spherical2 31Spherical2 3 2 30NodentUltrasonicbirefringencePNNL Ultrasonic measurements along the axis on Pipe2, R Defects, at 15degrees (approximately 3”) from TDC

# B-83 

# O AKRIDGE 

# N ATIONAL 

# L ABORATORY 

# (ORNL) D EMONSTRATION 

# T EST 

# D ATA

# B-84 This page intentionally blank.B-85Pipe Sample: 993CalibrationCrackLocationLength DepthMeasuredLengthMeasuredDepthinches fromend B inches% wallthickness186.4 2.558.7 586.4 582.4 2.544.4 3DefectNumberSearch Region(Distance fromEnd B)Start of CrackRegion fromSide BEnd ofCrackRegionfrom Side Binches inches inchesIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksIsolated CrackColonyof CracksTEST LINE 1NoneSCC2 226" to 242"NoneSCC1 242" to 254"NoneSCC3 210" to 222" 214" 216"Another isolated at 142"SCC5 140" to 152" 145" 148"NoneDefect Set:893Comments1multiple cracks; max = ~3/4"multiple cracks; max = ~1/2"multiple cracks; max = ~1/2"23TEST DATAType of SCC45Blank Area:Comments26" Diameter Pipe with Stress Corrosion Cracks; Length = 27 feetPipe Sample:CALIBRATION DATABenchmarkingof Inspection TechnologiesDetection of SCC - Page 1Sensor Design:Name:Date:Company:Venugopal K. Varma, Austion Albrught, and Philip Bingham1/27/2006Oak Ridge National LaboratoryEMAT shear Horizontal wave designmultiple cracks; max = ~1/4"multiple cracks; max = ~3 1/4"SCC4 175" to 187"NoneB-86B-87B-88This page intentionally blank.

# B-89 Calibration Note



# For calibration of SCC, a 26” pipe was provided with five SCC’s. These were located using liquid fluorescent magnetic particle inspection me thod. During the week of the testing we used the liquid fluorescent magnetic particle inspectio n to relocate the defects and had a hard time locating them. SCC 4 and SCC 5 could not be located and SCC3 and SCC 2 were indistinguishable from the scratches surrounding them. We could make out something SCC 2 &# area, but could not be confirmed. We clean ed the area using a wire brush and cleaner, but could not definitely identify the region having SCC. Only SCC1 could easily be identifiable, but this is more likely a manufacturing defect than an SCC. Due to lack of credible calibration data on 26 “ pipe, we had to base all algorithms on a previous 30” diameter training set.

Venu, Philip, and Austin

1/27/2006

# B-90 This page intentionally blank.

# B-91 

# N ATIONAL 

# E NERGY 

# T ECHNOLOGY 

# L ABORATORY 

# (NETL) D EMONSTRATION 

# T EST 

# D ATA

# B-92 This page intentionally blank.B-93Calibration DefectLocationVolume of Defect Depth of Defect Diameter of Defect Commentsinches from end A cubic inches inches inchesC1:18 0.028 0.25 0.375DefectNumberSearch Region(Distance from EndA)Location of DefectRegion from Side ASignificance of Defect(Output/Calibration Output)Volume of Defect (in3)(provided toparticipant after defectsignif reported)Depth of Defect (in)(provided to participantafter defect signif reported)Commentsinches inches cubic inches inchesNone52.55 1.31D6 56" to 62"None48" to 56"D2D4 42" to 48"45.62D3 34" to 42"NoneVolume = 0.02828" to 34"NoneD1 18" to 28"18.14 & 25.0618.14" = 1,25.06"=1.38For significance: defect calibration hole @ 18" = 1Vol @ 18" = 0.028 , Vol @ 25.06 = 0.039CALIBRATION DATADefectLINE 1TEST DATA6" Diameter, 0.5" Wall Thickness Pipe Sample, ~13' in lengthPipe Sample:Pipe Parameters:PLASTIC PIPE SAMPLEBenchmarking of Inspection TechnologiesDetection of Plastic Pipe Defects - Page 1Sensor Design:Name:Date:Company:Jim Spenik, Chris Condon, Bill Fincham, Travis KirbySubmitted 01/23/06NETLCapacitive sensor for Polyethylene Pipe Inspection0.99D5D7 62" to 70"66.36 1.15Volume= 0.037Volume = 0.033D8 70" to 76"NoneD9 76" to 84"NoneD12 98" to 104"101.03 1.61Volume = 0.045D11 90" to 98"Volume = 0.02D13 104" to 112"107.84 0.71Volume = 0.016D14 112" to 118"114.75 0.57Volume = 0.020D15 118" to 126"121.89 0.74We have indications that a consistant amount of material may havebeen removed along the entire lengthD16 126" to 132"None ?D17 132" to 138"None ?D19 144" to 150"146.76 0.71D10 84" to 90"87.15 0.43Volume = 0.020We have indications that a consistant amount of material may havebeen removed along the entire lengthD18 138" to 144"138.3 1.13Volume = 0.032Volume = 0.012B-94This page intentionally blank.

# A PPENDIX 

# C – D EVELOPER 

# C OMMENTS

# C-1 

# S OUTHWEST 

# R ESEARCH 

# I NSTITUTE 

# (S W 

# RI) C OMMENTS ON 

# P IPELINE 

# I NSPECTION 

# T ECHNOLOGIES 

# D EMONSTRATION 

# R EPORT

# C-2 This page intentionally blank

# C-3 

# Final Comments on
“PIPELINE INSPECTION TECHNOLOGIES DEMONSTRATION REPORT”

APPLICATION OF REMOTE-FIELD EDDY CURRENT (RFEC) TESTING TO INSPECTION OF UNPIGGABLE PIPELINES

OTHER TRANSACTION AG REEMENT DTRS56-02-T-0001 SwRI ® 

# PROJECT 14.06162 PIPELINE AND HAZARDOUS MATERIA LS SAFETY ADMNISTRATION U.S. DEPARTMENT OF TRANSPORTATION

SOUTHWEST RESEARCH INSTITUTE ®



# February 2006

Southwest Research Institute (SwRI) believes that the results of the demonstration testing indicate that the SwRI RFEC system is very promis ing as an inspection tool that can accurately detect and characterize wall-loss defects in pi pelines. The report showeda comparison of predicted vs. measured defect parameters with er ror bands of ±10% of wall thickness for defect depth and ±0.5 inch for defect length and depth. For the SwRI data, 68% of the predicted depths, 88% of the predicted lengths, and 88% of the pred icted widths were within those error bands. If the error band is increased to ±20%, then 91% of the predicted depths would be within the band. The depth prediction had a systemat ic error in that the predicted depths were generally less than the measured ones. If corrections are made to the SwRI depth prediction algorithm to reduce the systematic error (for example, by using the demonstration test de fect responses to correct the calibration approach), then even better results can be obtained. It is emphasized that the SwRI RFEC tool was designed to m eet the specifications and constraints of the Explorer II robot under developm ent by Carnegie Mellon University (as discussed in the SwRI comments on page B–4 of this repor t). The demonstration tests were thus conducted with sensors, instrumentation, data processing, scan speeds, etc. that are very representative of a field inspection system as integrated with Explorer II. SwRI therefore expects that results similar to those obtained in this dem onstration would be obtained with an actual inspection system and that no degradation in performance would be expe rienced by transitioning to field hardware and inspection conditions.

# C-4 

# Additional Information on the SwRI Remote Field Eddy

Current Technology and Design as Integrated with the Explorer II Robotic Platform

SwRI Remote-Field Eddy Current – Through funding support from PHMSA/OPS, Southwest Research Institute ® 

# has developed a remote-field eddy curr ent (RFEC) technology to be used in unpiggable lines. The SwRI RFEC tool is capable of detecting corrosion on the inside or outside pipe surface. Since a large percentage of pipelin es cannot be inspected using “smart pig” techniques because of diameter restrictions, pipe bends, and valves, a concept for a collapsible excitation coil was developed but found unnecessary fo r the pipe sizes and materials of interest in this demonstration. A breadboard system that meets the size, power, and communication requirements for integration into the Carnegie Mellon Explorer II robot was developed and used in the demonstration tests. This system is s hown in Figure 1. The demonstration system incorporates eight detectors, and data from all eight channels are acquired and processed simultaneously as the system is scanned along the pipe at speeds up to 4 inch/sec. All of the instrumentation, except for a DC power supply and a laptop computer (used for storage of the processed data), is located on the tool. Fi gure 2 shows the system design as integrated with the Explorer II robot under development by Carnegie Mellon Un iversity. The RFEC system can expand to inspect 6- or 8-inch-diameter pipe and can retract to 4 inch es to pass through obstructions.

Laptop Computer with CAN Bus Interface

Encoder Wheel

Electronics Sensors Excitation Coil

DC Power Supply



# Figure 1. SwRI RFEC tool used in demonstration tests

# C-5 

# Detector Module

Explorer Support Module Exciter Module

Figure 2. SwRI RFEC tool design as integrated with Explorer II robot: Top–Expanded for inspection with cover removed from exciter module, Bottom–Retracted to pass through restricted areas.

# C-6 This page intentionally blank

# C-7 

# G AS 

# T ECHNOLOGY 

# I NSTITUTE 

# (GTI) C OMMENTS ON 

# P IPELINE 

# I NSPECTION 

# T ECHNOLOGIES 

# D EMONSTRATION 

# R EPORT

# C-8 This page intentionally blank.

# C-9 

# Comments on the Comparison of Benchmarks and GTI Results

Albert Teitsma, Julie Maupi n, and Paul Shuttleworth

Gas Technology Institute 1700 S. Mount Prospect Rd. Des Plaines, IL 60018

25 October 2004



# Introduction During the week of 9 January 2006, GTI staff came to the West Jefferson facility of Battelle Labs in Columbus, OH to test a prototype RFEC inspection vehicle in 3 sections of 8 inch pipe. We reported on our test resu lts in a previous document. 6 

# In this document we comment on the benchmarks reported in “Pipeline Inspection T echnologies Demonstration Report” by Stephanie A. Flamberg and Robert C. Gertler.

Comparison of Benchmarks and GTI Results Table 1 below compares GTI results to the benchm ark data. There are two types of error in these results, systematic and random. The systematic er rors are the average readings in Table 1, while scatter gives the random error. A different resear cher analyzed the data from each pipe and the subjective components of the data analysis do s how. All three underestimated the defect lengths, in one case by half an inch with a scatter of .4 inches. Particularly for small deep defects, this is too large an error, but the tabl e also shows that proper analysis does give an acceptable precision (average=-0.139”, scatter=0.133). Pr ecision in the circumferentia l direction was not as good, but as pointed out in a previous report, remaining strength calculation such as B31G or RSTRENG do not use circumferential exte nt in the calculations.

Figure 1. Data with Pipe 3 corrected for calibration error. There was a serious depth calibration error for pi pe three, which made the scatter for the GTI results look worse than it was. Figure 1 show s the improvement with recalibrated data. GTI expected that the anticipated error would be ab out +/- 10% of the full wallthickness, as indicated by the lines in Figure1. Table 1 shows that more experienced analysts can achieve that, the scatter for Pipe 1 being 10%, while that for Pipe 3 was a mere 7%.

GTI’s sizing of the natural corrosion areas was excellent.

6 

# “Analysis of Sensor Benchmarking Tests: Remote Field Eddy Current Technique”, Julie Maupin, Albert Teitsma, and Paul Shuttleworth.

# C-10 Time to Take the Data Since time to take the data has become an i ssue, GTI has included results from its run with Russell NDE Systems, Inc. equipment, which GTI pl ans to use in its modules, in this report.

Figure 2. A faster run using Russell NDE Systems, Inc. instrumentation.

GTI inspected 23’ of Pipe 3 in 7 minutes us ing this instrumentation, which GTI brought along for demonstration purposes only. The speed was limited by the speed of our tow motor. The instrumentation can easily handle the 4” per seco nd specified for Explorer II. The unfiltered data in Figure 2 is a little noisier th an that obtained from the laborat ory lock-in amplifier, but more than good enough for the size of the signals ob tained during the benchmark tests. GTI concentrated on maximizing signal strength and minimizing power consumption. Speed at the very low speeds used by Expl orer II was never an issue.

For most of the measurements, it took GTI a littl e over half a day per run in Pipes 1 and 5, and a little longer in Pipe 3 using a si ngle lock-in amplifier to measure all sixteen channels. To ensure superior data quality the lock-in was allowed to settle nearly a second before reading the data from a sensing coil.

C-Scans C-scans obtained with the RFEC inspection do not have the resolution of the benchmark scans, but the correlation between them are excellent. Fi gure 3 compares the natu ral corrosion defect, P1-23. Similar results are obtai ned for the other defects.

# C-11 Figure 3. Excellent correlation between the RFEC results and the natural corrosion benchmark data.

Conclusion The results clearly demonstrate that the RFEC technique is eminently suited for inspecting transmission and distribution piping. The measur ements had excellent quality. However GTI’s analysis indicates that it takes experienced analys ts to translate the measurements into precise defect severity estimates. Although most of the results were not obtained at inspection speeds, the short run with more realistic field equipmen t showed that inspection at Explorer II speeds will not reduce the quality of the defect severity measurements.

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# Comments on Demonstration Results for the



# ROTATING PERMANENT MAGNET

INSPECTION TOOL

Prepared by Battelle

February 17, 2006

Theory of Operation

The rotating permanent magnet inspection method employed by Battelle at the Pipeline Inspection Technologies Demonstration is an alte rnative to the common c oncentric coil methods to induce low-frequency eddy currents in ferro magnetic pipe and tubes. Battelle’s technology consists of a pair of permanent magnets that rotate around a central axis in proximity to the inner surface of the pipe sample. The rotating perman ent magnet pairs are used to induce high current densities in the material undergoing inspecti on. Following fundamental laws of electrical induction, rotating permanent magnet pairs inside a pi pe along its longitudina l axis establishes an alternating electrical current in the wall of th e pipe. Figure 1, a cutaway drawing showing the rotating permanent magnet exciter, illustrates this c oncept. The current flows in an elliptical path around the magnets. When the magnetizer is verti cal, strong currents flow axially along the top and bottom of the pipe and circumferentially at the sides. When the magnetizer is horizontal, strong currents flow circumferentia lly at the sides of the pipe and axially at the top and the bottom. Finite element modeling shows that a two-pole magnetizer produces strong current densities at distances reasonably far away from the magnetizer. Although the current is complex at the magnet poles (where it is strongest), at dist ances of a pipe diameter or more away from the magnetizer it is uniform and sinusoidal. With this uniform energy induced in the pipe, simple magnetic field sensors can be used to detect the change in current densiti es in the pipe wall and thus pinpoint the location of defects and anomalies.

The development of this technology began in fall 2003 and is sponsored by The U.S. Department of Energy’s National Energy Technology Laboratory with cofunding from the Pipeline Research Council International. The first known use of this inspection method to detect corrosion was performed in September 2004.

# C-16 Figure 2. Illustration of the rotating pe rmanent magnet exciter and sensor location



# System Configuration as Demonstrated

Figure 2 shows the prototype used for the 8 in ch corrosion inspection benchmark demonstration. A pair of NdFeB magnets is mounted on a steel co re machined from 1018 steel. The magnets are 2 inches long, 1 inch wide, and 0.5 inch thic k; the magnet strength is 38 MegaGauss-Oersted. While the strong holding force secures the magnets on the steel core, copp er covers keep the magnets precisely aligned. The air gap between the magnet and the pipe wall is 0.5 inch. Wheeled support plates keep the magnet centered in the pipe. A va riable speed direct current motor is used to rotate the magnetizing assembly. The rotational speed used in this demonstration was 300 rpm or 5 Hz. The power requi red to rotate the magnets at this speed was about 70 watts. While this is above the availabl e power of 50 watts budgeted by Explorer II, this power requirement is significantly better than the 200 watts required in prior designs. Three pairs of axial and a radial Hall Effect sensors were mounted in 4 sensor shoes designed to ride on the ID of the pipe. While sensor to magnet sp acing of 8 to 10 inches provides stronger signal changes from corrosion anomalies, the distance from the magnet to the sensor was 13 inches to meet EXPLORER II specifications. To continuo usly monitor rotational speed, a small magnet was attached to the shaft and an additional Hall Effect sensor was used to produce a synchronous signal.

# C-17 Figure 3. Rotating permanent Magn et Inspection system as configured for the technology demonstration



# A 24 channel real-time data recorder system was implemented and fundamental experiments were conducted to provide data to aid in the de sign of the rotating ma gnetizer. A system was designed to simultaneously record and process 11 sensor pairs, the sync signal and one open channel. The block diagram of th e data recorder system is show n in Figure 3. The heart of the recorder is the National Instruments PXI- 4472, an eight-channel dynamic signal acquisition module for making high-accuracy frequency-doma in measurements. The eight NI PXI-4472 input channels simultaneously di gitize input signals over a bandw idth from 0.5 Hz to 45 kHz. Three PXI-4472 modules were synchronized to pr ovide 24 channel input using the PXI chassis and a star trigger bus. The PXI chassis communi cates with a desktop computer using a fiber optic link. The desktop computer is used to analyze the signals using a lock-in amplifier approach, as described in a previous DOE semi annual report. LabVIEW software modules for lock-in amplifier measurements were used in th e development of a custom data acquisition and display program.

Figure 3. The block diagram of the data acquisition system



# Display of results

# C-18 The data acquisition and processi ng hardware and software proce ssed signals and displayed data in real time during the demonstra tion. A typical output of the data recording package is shown in Figure 4. In real time display mode, the data scrolls along the monitor as the inspection tool traverses the pipe. The upper and lower graphs show the axial and radi al sensors respectively using a stacked line plotting routine, a format familiar to pigging vendors and users of pipeline inspection technologies. In this figure, the signal from an axially short, circumferentially wide metal loss anomaly can be seen in the middle channels of each sensor type.

Figure 4. Screen capture of custom LabV IEW data acquisition and display program



# The results submitted by Battelle on January 26, 2006 (contained in appendix B) included signals from each reporting area in a uniform format. An example signal is shown in Figure 5 for pipe sample 2, search area 10. The upper and lower st acked graphs show the signals from the axial and radial sensors respectively; the color codes repeat so that sensor pairs can be correlated. Since only about 70 degrees of the pipe was inst rumented, the center sensor was positioned so that it traversed the centerline of the defect. In some of the gr aphs in appendix B it is evident that the tool rotated slightly as it was pulled through the pipe because some of the corrosion signals are greater in other sensors. The signa ls provided with the repo rt were plotted on the same scale for quick visual comparison. For det ection and assessment, signals were amplified so that smaller corrosion areas could be more eas ily detected and asse ssed. Other graphical representations, including plotti ng axial versus radial signals, are proving to be useful in assessing corrosion. A scaled t opographical map of the corrosion de pth is included at the bottom of Figure 5 after it was flipped (t he tool was pulled from right to left). The two humps in the stacked graphs correspond to the two pits in the image. In th e reported results, the presence of single or multiple pits was indicated in the co mment section. The depth assessment was based on the largest signal since the data reporting form specifica lly requested maximum depth.

# C-19 Figure 5. Signal from pipe sample 2, search area 10



# Comments on Results

The results presented in the main section of th e demonstration report are representative of the current capability of the rotating permanent magn et tool. This comparatively new inspection methodology is in its third year of developmen t. Specific comments on detection and sizing results are provided next.

Detection. The results of the demonstration showed that all corrosion anomalies were detected and one additional anomaly was falsely detected. The false call anomaly was assessed as small and not detected in all pulls. The spacing between sens ors (sensor pitch) of the demonstration configuration was 0.5 inches. For corrosion with shallow depth and a width and length nominally the same as the sensor pitch, a dete ctable signal may only be produced by a sensor traveling directly underneath the anomaly. Tw o sensors straddling the same anomaly may not produce a signal. Future implementations may n eed a finer sensor pitch to improve results.

Corrosion sizing. A corrosion anomaly locally increases th e density of the currents that are induced by the rotating magnetizer. The local change in current density is also influenced by the length and width. The algorithm for estimating the depth of th e corrosion anomaly includes these three measures, in a manner similar to magn etic flux leakage data analysis methods. Data from the calibration anomalies and the first benchm ark demonstration were used to establish the sizing algorithm. The unity plot shown in the main report indi cates a good correlation between measured and predicted values, how ever there is a gene ral tendency to under-c all the depth. This was the first algorithm developed for corrosion anomaly depth assessment. Additional data and algorithm refinement should help improve results.

# C-20 Natural Corrosion Sample. The natural corrosion sample was difficult to assess because of the unexpected weld. In hindsight, the signals were quite clear. Figures 6 and 7 show the reported raw data with new annotations for lines 1 and 2 respectively. In the re sults reported on January 27, 2006 for these lines Battelle discussed:

• Line 1 - A large area of general corrosion of variable depth that sp ans the entire sensor width. The corrosion is close to the weld, altering both si gnals. A large wide corrosion area at 128"

• Line 2 - An area of general corro sion of variable depth that spans most sensors. A large wide corrosion area at 128"

The signal 128 inches from the end was the unexp ected weld signal. The general corrosion on either side of the weld corresponds to the meas ured results; however the close welds caused interference and sizing was not attempted at this time. While the natural corrosion pipe was complex, it is only one of many unique challenge s that must be faced when implementing inspection technology and the e xperience will be valuable in future developments.



# Summary

The benchmarking results are a representative asse ssment of the current state of development of the rotating permanent magnet inspection system. The planned improvements of this technology should advance the capability of this inspec tion system. Battelle is currently working on reducing magnetizer size, increasing rotation speed, and increasing the separation distance between the magnet and the pipe. Separations of over an inch appear to be practical, which will aid in the implementation of this technology. The rapid advances of this new inspection technology should make this methodology useful for unpigable pipeline applications in the near future.



# Acknowledgement

The U.S. Department of Energy’s National Ener gy Technology Laboratory is sponsoring this development with cofunding from the Pipeline Research Council International. However, any opinions, findings, conclusions, orrecommendations expressed here in are those of the authors and do not necessarily reflect th e views of these sponsors.

# C-21 Figure 6. Natural corrosion results line 1

Figure 7. Natural corrosion results, line 2

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# Comments on NETL and Pipeline & Hazardous Materials Safety

Administration pipeline inspection technologies demonstration

Submitted by: Paul D. Panetta Pacific Northwest National Laboratory Richland, WA 99352 paul.panetta@pnl.gov (509) 372-6107

The Pacific Northwest National Laboratory (PNNL ) participated in the Pipeline Inspection Technologies Demonstration during the week of January 9, 2006. The main focus of the demonstration was to rank the severity of de nts based on ultrasonic measurements of the mechanical properties and the presence of plastic st rain. This approach is dramatically different than the current assessment based solely on dime nsional measurements. The advantage of this approach is that the reliability of the pipeline can be determined based on material properties and how they change with time and damage, ra ther than the size and shape of a dent.

Measurements were performed on two 24 inch diam eter pipes containing dents and dents with gouges. Pipe 1 contained 3 rows of dents fr om a track how with a very small separation distance, on the order of a few inches in some cases. The total number of dents exceeded 40 dents. The operation of creati ng these dents and dents with g ouges created a significant amount of distortion to the pipe and ovalization of the pipe. In-servi ce pipelines with the amount of denting are highly unlikely and this pipe does not represent a realistic pipeline operating scenario. Despite this significant distortion resu lts were promising. Pi pe 2 contained 10 dents and 11 reporting locations. All dents were successf ully detected and estimates of the size were provided. The ultrasonic strain measurement corre ctly ranked 7 out of th e 9 reporting locations for 100% detectability and 77% acc uracy on ranking severity.

The sensor was a non contact electromagnetic ac oustic transducer (EMAT) that was scanned along the axis of the pipe at several distances from the dents placed at top dead center. The sensor and cart are shown in Figure 1. Figure 2 shows the amplitude and ultrasonic measurements along pipe 2 with the sensor pl aced 15 degrees from top dead center. The amplitude clears shows a deviation at each repor ting location with a dent and no deviation where there is no dent. The ultrasonic shear wave birefringence is i ndependent of thickness which is critical for characterizing mech anical properties due to deformation because a simple thickness measurement is NOT an accurate assessment of strain.

The inspection speed was as fast as 5 inches per second and the electronics can operate as fast as 4 or 5 feet per second (~3 MPH). The measuremen ts were performed in a 24 inch pipe and are amenable to pipes as small as 4 inches in diam eter. The technology proved to be very sensitive to mechanical damage due to dents and is also ideal for application where pipelines are bent due to subsidence or other earth movement. This technology is ready for incorporation onto robotics platforms and for field testing and subsequent commercialization for sp ecific applications.

# C-26 EMAT Sensor

Motor for

sensor rotation Springs for smooth motion past dents



# Figure 1. Photo of the ultras onic sensor and scanning cart.

0 10 20 30 40 50 60 70

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Distance (inches)Ultrasonic Amplitude



# -0.10 0.00 0.10 0.20 0.30 0.40 0.50Ultrasonic thicknessindependent measurement



# Amplitude 2 Cylindrical 1 Spherical 1 Spherical 2 3 1 Spherical 2 3 2 3 0 No dent



# Ultrasonic birefringence 

# PNNL Ultrasonic measurements along the axis on Pipe 2, R Defects, at 15 degrees (approximately 3”) from TDC



# Figure 2. Amplitude and ultrasonic birefringe nce as a function of distance along pipe 2.

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# C-29 SCC detection using Shear Horizontal EMAT

Based on the results, we feel that the ORNL SC C detection system using shear horizontal wave EMAT detection has performed very well for the te st conditions. In this response, we address areas pertaining to: training data issues, lack of data on SCC depth, additional defects along test line 1, and false positives. With these comments concentrating on issues wh ere the results are in question, we would like to emphasis that the sy stem performed very well for the test and addressing these issues will only improve or better clarify the results.

Training Data: The current ORNL set-up for detecting SCCs w ith the shear horizontal wave EMAT uses transmitted signals to assess the presence of a crack. The signals from ‘ no-flaw’ regions are compared to the signals from ‘flaw’ regions to identify cracks. Th e key issue in performing this measurement is the determination of features, de rived from the response signals that separate flawed regions from those with no flaws . In the current algorithm, wavelet based features from both ‘ flaw’ and ‘ no-flaw’ regions are used to establish clas ses (SCC, no-flaw, other anomaly). Since this technology requires tr aining data of known defect and no-defect regions, a 26” training pipe was provided in addition to the test pipe during our visit to the test facility. Unfortunately, we were unable to generate a proper training set from this test pipe due to the quality and the discrepancy in the location of the flaws. Instead, previous data collected from a 30” pipe for training were used. Although the mo de frequencies were di fferent for the 26" and 30" pipe due to change in wall thickness and pipe diameter the results were still satisfactory. This indicates a robustness of the training sets across pipe di ameters and thicknesses. The system performance would have only improved ha d we used a training set generated out of similar pipe geometry.

SCC Depth Data: Defect sizes were given in terms of length a nd area of crack on the pipe with no depth information. Liquid fluorescent magnetic part icle inspection for detecting SCCs does not contain any information on the depth of the crack , while the EMAT based approach has a direct dependence on it. Hence, some very small crack s detected by magnetic particle method may not be detected by EMAT due to thei r depth being small. This is a possible reason for SSC2 not being detected. With the know ledge of SCC depth, we could have determined how well the system is able to detect the severity of the crack.

Additional Known Defect s in Test Line 1: In testing, we were instructed to test along three differe nt lines of the test pipe to determine the presence of defects over particul ar spans along each line. Figure 1 shows the pipe layout for the test. Each test box (blue boxes labeled SCC1 – SCC14) along w ith every defect previously identified on the pipe (pink boxes labeled 4-9, 15 -20) are pictured. The dashed lines represent the three scan lines. As mentioned in the results, the SCC defect we were to locate in SCC3 is defect 8 (far left side of box). However, we positioned this defect to the right by several inches. Since the EMATs scans an arc of ~12 inches around the circumference of the pipe, the SCC boxes within the figure have been drawn with 12 inch height to show the area covered by the sensor. From the figure, we see that defect s 17, 18, and 19 are all on th e upper edge of SCC3.

# C-30 Figure 4. Test setup.



# Our defect detection signal is essentially a dist ance measurement from the no-defect class within our feature space. This distance is pictured in Figure 2 for the SCC3 region. Red lines show boundary of box SCC3 and the approximate locati ons of defects 8, 17, 18, and 19 are shown in pink text. In our response to th e test, we listed the defect in the SCC3 box based on the large signal that appears to correspond to defect 18 (a fairly large incl usion). From the signal, we do feel that we are seeing the intended defect 8 as well but did not list it due to its location straddling the boundary of the SCC3 region.

# C-31 Figure 5. Defect response signal for SCC3 area.



# False Positives: As mentioned in the results, we also identifie d a false positive on each scan line. The EMATs did indicate flaws in areas where they were none, and this could be the result of not having the baseline data or the algorithm needing further refinement. Lack of good natural SCC data has been one of the difficulties we faced while developing this technology. We have created synthetic SCCs using electrical discharge m achining (EDM), however, EDM machined SCCs do not give a signature truly characte ristic of a natural SCC. Figure 3 shows the signals returned for the three false positives that have peaks similar to our previous experience with SCC signatures. Red lines delineate the regions of interest. The false positive on line 1 (Figure 3a) shows a series of peaks each similar in shape to an SCC res ponse. The false positiv e in line 2 (Figure 3b) shows a well-isolated peak typical of an SCC res ponse. The false positive in line 3 (Figure 3c) shows an SCC type response on the right side of SCC14 box. Similar bumps also can be seen near 160" mark but were not marked as SCCs due to the low dome shape of the response.

# C-32 (a) (b)

(c)
Figure 6. False positive signals for scan lines 1, 2 and 3 are shown in (a), (b) and (c) respectively



# Conclusion: As mentioned earlier, we feel the ORNL SCC de tection system performed well in this test. Lessons learned from the tests ar e: 1) Training data may not be necessary for each pipe geometry being investigated, and 2) Inform ation on SCC depth is needed to fully characterize the system performance. We feel that the system perfor mance will continue to improve as more training data from natural SCCs are collecte d and used to train the algorithm.

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# Analysis of Sensor Benchmark Tests 

# Capacitive Sensor for Polyethylene Pipe Inspection

Prepared by: James Spenik, Chris Condon, Bill Fincham, Travis Kirby National Energy Technology Laboratory 3610 Collins Ferry Road Morgantown, WV 26505

February, 15, 2006

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# Introduction:

Representatives from the National Energy Tec hnology Laboratory demonstrated polyethylene pipe inspection technology at Battelle’s West Jefferson Pipeline Simulation Facility near Columbus, OH. The technology was demonstr ated January 10 – 12, 2006 by James Spenik (REM), Chris Condon (REM), Bill Fincham (Parsons) and Travis Kirby (WVU).

Battelle provided a 13-foot length of 6-in ch nominal diameter, 0.5-inch wall thickness polyethylene pipe. Holes and saw cuts were plac ed into the top outer surface of the pipe along an axial line. Twelve defects we re placed within nineteen 6-inch long search regions. Eight of the regions did not contain a de fect, one region contained two de fects. The line of defects was covered thus the experimenters did not know their location when data was collected. However, a calibration defect was available whose char acteristics and location was known to the experimenters.

The probe was able to identify the defect in every search re gion without false positives.

Technique:

Abnormalities in the pipe wall are determined by changes in the dielectric properties of the wall material. An electric field is projected thr ough the pipe wall by the probe head (Fig. 1). The wall material behaves as the dielectric component of a capacitor. This arrangement formed the probe head of the sensor device. Since the dielectri c constant of polyethylen e is greater than that of air (or natural gas) an absence of material wi thin the electric field will manifest itself as a decrease in capacitance.

Figure 1 Projection of El ectric Field through Pipe Wall

The probe head and associated electronics we re mounted on a platform designed for this particular test (Fig. 2). The pr obe head was mounted 5.5 inches fr om the back circular disk of the 9.25-inch long platform. A 5.5 inch diameter di sk was mounted at each end of the platform. In future use, the probe could be in corporated on existing platforms.

The platform was propelled thr ough the pipe using a stationa ry stepper motor and nylon filament. An optical encoder was used to determ ine probe position within the pipe. Data were transmitted using RF transmission via Bluetoot h technology. Another option would be to store the data onboard and retrieved at a later ti me. Power was supplied using an on-board 9-volt Dielectric Material ( wall ) Probe head

Field Lines Defec t

# battery. The data transmission rate for this particular demonstrati on was controlled by the optical encoder and stepper motor. Capacitance data were to be transmitted every forty counts of the optical encoder (0.09 inch ax ial movement) but this value ma y have varied a few counts. The stepper motor moved the platform at a rate of approximately 0.09 in/s. The sampling rate was approximately 1 Hz for this configuration due to the constraints previously mentioned. Thus the transit time through the pipe was approxima tely 15 minutes. However, the electronics package used is capable of transmission rates of between 45 – 90 Hz and modifications to the package would allow transmission rates in the MHz range.

Figure 2 Platform with Probe Electronics

Data collection/analysis:

Twenty traverses were performed during the three days of data ac quisition. The first ten were preliminary to identify problems. These difficultie s were not related to th e function of the pipe defect sensor but rather sensor movement. Initially, the optical encoder did not react to movement along the surface of the yellow polyethyl ene pipe. This was an unforeseen problem since, in an earlier test, the encoder reacted in black polyethylene pipe. The problem was resolved by placing a strip of mate rial visible to the encoder on the interior lower surface of the pipe. Movement of the platform would be halted due to a sligh tly underpowered stepper motor. The edges of the platform disks were lubricated with graphite which minimized the problem. The deviation of the probe head from a linear pa th was minimized using guide line attached to the bottom of the pipe and through the bottom of both platform disks. These problems were identified and solved during the first ten traverses. Data from the second set of ten traverses were useful and provided data for statistical analysis.

Tests commenced with the rear disk approximately 1.5 inch from the “B” end of the pipe placing the sensor head at the 149 inch position of the 156 inch (13 foot) pipe (Fig. 3). Tests concluded with the probe head at the 7 inch position. Run11 – Run 20 were compiled to determine the position of anomalies within the polyethylene pipe. Probe Head

# Figure 3 Path of Probe Through Pipe

The average number of data points accumula ted for each run was 1619 points corresponding to a measurement for each 0.0877 inches of travel. Howe ver, this number varied between runs with a standard deviation of 46. These discrepancies can be attributed to either binding of the stepper motor or variations in the trigge ring level of the optical sensor. The focus of the research was creation of the probe; the platform was desi gned only after conforma tion of the teams’ participation in the demonstration was received. Data were post processed to determine the exact position of each defect within each search region in the following manner:

1. Data were aligned so the minimum capacita nce for each run near the calibration hole coincided. (Minimum capacitance corres ponds to the center of the anomaly)

2. Since the total length of the traverse and the tota l number of data points were known, the ratio of these numbers yielded an initia l estimate of step size for each run.

3. The data for each run was se parated by search region.

4. The position and value of the minimum capacitance value within the search region for each run was determined.

5. The average position of the minimum within the region was determined.

6. Each run was realigned within the region so the minimum was located at the average minimum position.

This method was effective; however, cumulative e rror caused the position of the anomaly within a search region to be progressively misinterpret ed. The measured positi on and actual position of the defect in search area D1 was at 25 inch, howev er, the actual position of the defect in search area D19 was 148” and the measured position was 146.8” Again, this is not due to sensor error but rather due to positioning erro r. All defects were identified with the exception of a binary defect (two holes separated by 0.5 inch on centers) located at position D15 which we identified as a single entity. The probe in its current configuration was not designed to separate binary anomalies separated by less than an inch.

Although it was not part of the be nchmarking demonstration, an at tempt was made to provide a comparative value of volume of material rem oved by the defect. Only moderate success was achieved in this endeavor. The reason that defi nitive volumetric values could not be determined was because the defects presented in the pipe could be consider ed to have three variables: diameter, depth and type (round hole or saw cut). Due to the nature of the electric field produced A B Traverse Direction

# by the probe, the depth and diameter cannot be comb ined into the single va riable volume. Since the electric field strength diminishes as a func tion of distance from the probe head, a smaller volume closer to the probe head is seen as e quivalent to a larger vol ume further away. The output from the current probe de sign yields two values: capacitanc e and change in capacitance with respect to axial position. Therefore there were three unk nowns and only two equations and thus the volume of material re moved was indeterminate. A future design of the probe allowing circumferential measurements will allow the development of an algorithm to define defect volume.

Figures 4 through 7 illustrate the typical probe re sponse when a defect was encountered. Each figure compiles the ten runs taken within an eight -inch long region of intere st. The abscissa is the variation from minimum capacitance within th e region and the ordinate is the linear position. Figure 4 shows the calibration defect and the prob e response. Figure 5 shows a typical response to a round defect and Figure 6 indicates the respons e to a saw cut. Figure 7 indicates the probe response in a region with no known defects. Th e presence of an anomaly typically produced a variation of 4000 aF. Variations in a region without defined a nomalies were typically 500 aF.

Conclusion:

The probe successfully identified the position of a ll defects within the s earch regions and had no false positive results. Deviations from the precise position of the defects within the search region can be attributed to the mean s of locomotion and position identif ication procedures. The data acquisition rate can be markedly increased w ith a superior locomoti on scheme. Further devlopment to this technology will produce a device th at can be inserted into in situ natural gas pipelines and determine their integrity.

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# Figure 4 Calibration Hole and Probe Response (18” position)

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# Figure 5 Round Hole Defect and Probe Response (25” position)

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# Figure 6 Saw Cut Defect and Probe Response (102” position)

# Figure 7 Probe Response with no Defect (102” position) 

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