E-ssentials. TÜV SÜD Vol. 7 June PetroChem Technical industry e-news updates essential to your operations

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1 TÜV SÜD E-ssentials PetroChem Technical industry e-news updates essential to your operations CONTENTS: PetroChem Experts to Present at ICPIIT Conference 02 PetroChem Hosts Open House Events During ICPIIT Conference 02 Nondestructive Testing: A Techniques Primer 03 Using Three-Dimensional Laser Scanning for Above-Ground Storage Tank Integrity An Overview of Pipes and Tubing Inspection Techniques

2 Page 2 Editorial Dear Reader, Welcome to the latest issue of PetroChem E-ssentials, the e-newsletter from PetroChem Inspection Services, a subsidiary of TÜV SÜD America. The release of this issue of PetroChem E-ssentials coincides with the 2013 International Chemical and Petroleum Industry Inspection Technology (ICPIIT) Conference XIII, which begins on June 12th in Houston, TX. Technical experts from PetroChem Inspection Services, including William Bobbitt and Idamarie Carden, will be among the featured speakers and presenters there. If you re attending the Conference, I hope that you ll find time to attend one or more of these excellent presentations. Meanwhile, see the brief article entitled PetroChem Experts to Present at ICPIIT Conference for more information. PetroChem will sponsor a series of Open House events at our Pasadena, TX headquarters during the week of the ICPIIT Conference. See our brief article PetroChem Hosts Open House Events During ICPIIT Conference for more details about what we have planned. Or, contact Patty Sweeten at We look forward to seeing you there. Speaking of the ICPIIT Conference, I ll be delivering one of the Conference Plenary Addresses on the growing acceptance and use of new nondestructive testing (NDT) methods and techniques. To provide our readers with some background information on this subject, we ve reprinted in this issue our 2011 article Non-Destructive Testing Techniques: A Primer to aid in the selection of appropriate NDT methods for specific applications. Continuing on the NDT front, eddy current testing and 3D laser scanning are two NDT methods gaining widespread use in recent years. Our articles Using Three-Dimensional Laser Scanning for Above Ground Storage Tank Integrity and An Overview of Pipes and Tubing Inspection Techniques discuss the applications and advantages of each of these NDT methods. Thanks! Gerhard Abel President PetroChem Inspection Services PetroChem Experts to Present at ICPIIT Conference Technical experts from PetroChem Inspection Services will be among the featured speakers and presenters at the upcoming International Chemical and Petroleum Industry Inspection Technology (ICPIIT) XIII Conference, to be held on June 12-15, 2013 at the Crowne Plaza Houston Northwest- Brookhollow in Houston, Texas. The ICPIIT Conference focuses on industry innovations and solutions in the area of nondestructive testing (NDT). The four-day event offers technical sessions and exhibits addressing a range of issues, including pipeline and piping, pressure vessels, storage tanks, chemical and refinery plants, equipment for transportation, inspector certifications, codes, standards, regulations, and risk-based inspections and evaluations. Gerhard Abel, President of PetroChem Inspection Services, will deliver a Conference Plenary Address on Thursday morning, June 13th. His address, Application of Various NDT Technology and Market Acceptance of Next Generation Technologies, will provide an overview of the NDT technology choices available to end users. In addition to Mr. Abel s address, PetroChem s William Bobbitt will discuss Code Quality Inspection Through Computerized Radiography, in a technical session scheduled for Wednesday, June 12th, at 3:15pm. And PetroChem s Idamarie Carden will discuss Three-Dimensional Laser Scanning of Above-Ground Storage Tanks on Friday, June 14th at 1:30pm. Additional information about the ICPIIT XIII Conference and details about the Conference technical program are available at asnt.org/en/majorsitesections/events%20and%20 Publications/Upcoming%20Events/ICPIIT%20XIII. aspx. PetroChem Inspection Services is a Gold Sponsor of ICPIIT XIII, and will also be exhibiting at the Conference. If you re attending the Conference, please stop by our exhibit booth #31, meet our petrochemical industry experts, and learn more about how PetroChem can help you address your specific NDT testing challenges. If you can t make it to ICPIIT, we invite you to view PetroChem s product videos at com/videos.cfm. PetroChem Hosts Open House Events During ICPIIT Conference PetroChem Inspection Services will host two Open House events at its Pasadena, TX headquarters during the International Chemical and Petroleum Industry Inspection Technology (ICPIIT) XIII Conference, to be held on June 12-15, The Open House events are scheduled for Wednesday, June 12th, from 11am-4pm, and Thursday, June 13th, from 3-8pm. Each Open House event will include informative presentations on advancements in nondestructive testing (NDT) equipment and techniques, as well as plenty of food, refreshments, and entertainment. PetroChem will provide Conference attendees with complementary shuttle transportation to its Open House events from the Crowne Plaza Houston Northwest-Brookhollow, the location of the ICPIIT Conference. PetroChem s Open House events are an excellent opportunity to learn more about our wide range of testing and assessment services and capabilities, and to discuss your particular challenges with our technical experts in an informal setting. For more information about PetroChem s Houston Open House, please contact Patty Sweeten at or at Patty_Sweeten@PetroChemIntl.com.

3 Page 3 Nondestructive Testing: A Techniques Primer In the petroleum and hydrocarbon refining and processing industries, nondestructive testing (NDT) is an essential tool that can be used to evaluate materials and systems while maintaining and preserving costly plant and infrastructure investments. However, there are a number of NDT techniques from which to choose, each utilizing unique technologies that are appropriate for specific applications. This article provides an overview of various NDT techniques and their uses. REAL-TIME RADIOGRAPHY (RTR) RTR uses low dose x-rays to produce images. However, unlike conventional radiographic testing, RTR captures images electronically rather than on film. This approach all but eliminates the lag time between initial exposure and the resulting image. RTR testing units are usually lightweight portable devices that include a highly sensitive x-ray imager and a battery-operated x-ray tube, making them ideal for portable field operation. These devices are also typically equipped with electronic recording capabilities that allow for the capture of still images or video. RTR is most commonly used for rapid inspection of pipes, and is capable of scanning anywhere from 100 to as much as 500 feet of pipe per day, depending on the application. This speed allows the inspector to quickly and economically identify areas of concern that can be further examined with more expensive testing methods. RTR is a particularly useful technique in corrosion under insulation (CUI) surveys, and can identify areas of wet and saturated insulation. RTR is also useful for inspecting welding locations in insulated pipe, and can easily locate welds in support of positive material identification (PMI) programs. However, the use of RTR is limited to pipes and insulation that do not exceed 27 inches at the tangent. GUIDED WAVE (GW) ULTRASONIC INSPECTION GW ultrasonic inspection involves the use of a testing unit that generates ultrasonic energy. The energy is directed down the length of a pipe and returns to the transducer ring in the testing unit in a pulse-echo fashion. Any change in the cross section along the length of the pipe generates reflected energy (i.e., ultrasonic signals) that can be analyzed and used to identify areas of wall loss within a pipe. GW ultrasonic inspection provides 100% coverage throughout the pipe s test length, even when only limited access is available. Therefore, it is commonly used for in-service inspection of otherwise inaccessible piping, such as elevated piping or piping used at road crossings. However, as a screening tool for piping, GW testing provides qualitative but not quantitative results. Defective areas that are identified using GW testing require the use of complementary testing methods or visual inspection to acquire specific data. Further, a number of variables affect the range and sensitivity of GW testing. For example, travelling through bends distorts the GW signal, making feature or defect classification unreliable. Electro-Magnetic Acoustic Transducers (EMATs) Unlike conventional UT transducers, EMATs create ultrasonic energy by inducing an alternating current within a magnetic field. EMAT testing units have two probes, a pulser and a receiver. The pulser sends an ultrasonic signal in both directions around a pipe s circumference, and the receiver receives the signals from both directions. Changes in the UT signal represent changes in the piping material, such as wall loss. An EMAT inspection can be conducted on any piping that is physically accessible, including dock lines, sleeper racks and elevated piping. It can detect small, isolated defects down to 1/8 inch in diameter, as well as generalized wall loss from corrosion or erosion. EMAT also allows for the rapid screening of long pipe lengths, and can inspect as much as 1000 feet of piping in a single shift while providing qualitative results and identifying defect locations for follow-up inspection. PHASE ARRAY (PA) ULTRASONIC INSPECTION PA ultrasonic technology electronically modifies the acoustic probe characteristics of conventional transducers. PA testing units use multiple elements in a single housing, excited at specific intervals, to generate uniform wave fronts at specific angles. Electronic images are then created from the received ultrasonic energy, allowing for the identification of defects and their location. PA ultrasonic inspection offers high speed electronic scanning without moving parts, and can inspect multiple angles using a single, electronically-controlled probe. Data can be collected in either manual or encoded modes. Most ultrasonic techniques for flaw detection can be applied using PA probes.

4 Page 4 However, environmental temperature can impose limitations on the use of PA ultrasonic inspection, due to the sensitivity of the small electronic components and transducer elements used. Other limitations on the use of PA ultrasonic technology include the size of the transducer footprint, and low amplitude responses from energy diffusing or scattering reflectors, such as material porosity. TIME OF FLIGHT DIFFRACTION (TOFD) ULTRASONIC INSPECTION ToFD is a multi-mode ultrasonic inspection technique that measures the flight time of the sound energy through the material under inspection, from one probe to another. ToFD ultrasonic inspection is typically used to inspect welds and base material for flaws, cracks, root erosion, corrosion and cladding conditions. It can completely cover a typical butt weld, the heataffected zone (HAZ) and the base material adjacent to the weld from a single position. ToFD ultrasonic inspection can be performed in less time than a manual ultrasonic inspection, and can more accurately evaluate the through-wall dimension of defects. ToFD inspection devices can also produce an image that can be archived for repeat inspection, as a tool for ongoing monitoring of an identified defect. Perhaps most important, a ToFD inspection does not interrupt production compared to other radiographic inspection techniques. consistently articulated and encoded data. AUT applications include weld and cladding inspection, corrosion mapping, and inspection for hydrogen induced cracking (HIC) and stress-oriented HIC (SOHIC). AUT-based inspections offer consistently incremented and repeatable scanning, and increased speed and accuracy of inspection. These advantages enhance post-collection data analysis, including fitness for service calculations. AUT is also capable of calibration verification. The limitations of AUT inspection largely reflect the way in which AUT equipment operates. For example, AUT systems typically use magnetic wheels to secure them to equipment under test, so surfaces must be clear of loose debris. In cases where non-ferromagnetic materials are being evaluated, tracks of some sort much be attached to the material to hold the AUT in place. Finally, AUT systems typically require power to operate the electronics and motor controllers, although smaller AUT systems may be operated with battery power. environmentally-induced cracking. ACFM-based inspection equipment is capable of detecting and sizing cracks in most metals, and can be used as a replacement for conventional magnetic particle and liquid penetrant testing. ACFM can be used to inspect a wide range of materials, including carbon steel, stainless steel, aluminum, and nickel-chromium-based super alloys. ACFM inspections do not require extensive cleaning of inspected surfaces or the removal of coatings. ACFM-based inspections are also 60-70% faster than conventional inspection, often allowing rapid, single-pass inspection. CONCLUSION Each material and system inspection situation typically presents a complex set of unique circumstances and challenges. The proper selection of an appropriate NDT inspection technique must be made in that context, and involves the careful evaluation of the specific attributes and benefits of each technique. An experience consultant can provide valuable perspective and advice when it comes to identifying the right inspection technology for each situation. For additional information about NDT inspection options, or NDT inspection services offered by PetroChem. visit AUTOMATED ULTRASONIC TESTING (AUT) AUT is the automated robotic deployment of conventional or advanced ultrasonics to produce Alternating Current Field Measurement (ACFM) ACFM was originally developed for use on offshore structures in the North Sea, and has been used in the United States to inspect pressure vessels for Using Three-Dimensional Laser Scanning for Above-Ground Storage Tank Integrity The use of three-dimensional (3D) laser scanning technology to evaluate above-ground storage tanks can provide owners and operators with a significant amount of information regarding the integrity of their storage tanks. Compare with other types of data collection techniques, laser scanning can generate millions of data points, ensuring increased accuracy in tank evaluation. In addition, advanced software can be used to facilitate the verification of future laser scanning measurements against baseline data. This article will describe 3D laser scanning technology, its use in evaluating above-ground storage tanks, and its benefits. THE TECHNOLOGY 3D laser scanners typically incorporate a laser source and a mirror assembly rotating at high speeds. Light from the laser source is reflected off the mirror in a programmed sequence, and then travels until it encounters a targeted object. The light is then reflected off of the object and a portion of the reflected light is picked up by the scanner. Sensors within the scanner are then used to compare the emitted light with the reflected light, allowing the scanner to calculate the precise dimensions of the object. Modern laser scanners can collect as many as one million measurements per second. Therefore, a complete scan of a targeted object can consist of

5 Page 5 millions of data points. The actual number of data points that need to be collected will depend on the scope of the tank inspection and the requirements of the customer. However, a larger number of collected data points will yield a higher resolution image. 3D LASER SCANNING APPLICATIONS In evaluating above-ground storage tanks, 3D laser scanning can be used for a variety of different assessments. The resulting image produced by the scanner can be used simply to identify the dimensions or placement coordinates of a tank. In more complex assessments, laser scanning can help determine whether a tank has tilted or deformed over time due to use or internal pressures. Using application software designed expressly for the purpose, multiple scans produced over an extended period can be compared to identify the speed and extent of tank structure changes. Currently, 3D laser scanning is most commonly used for the strapping and calibration of tanks, measuring and calculating finite analysis on tank bottoms, dike volume calculations, and shell deformations. The images produced by 3D laser scans enable a complete and thorough evaluation of a tank bottom. Scan data is stored electronically, and can be reexamined and reevaluated in the future. This capability is especially useful when comparing settlement evaluations and ground movement of a tank foundation. THE SCANNING PROCESS The objective of 3D laser scanning is to ensure the collection of 100% of the data related to the outside of the tank and the surrounding containment area. At a minimum, scans should be conducted from the north, east, south, and west quadrants of the tank, as well as from the center of the tank. The actual number of external scans required in order to obtain a complete external survey will depend on the number of obstructions surrounding a tank, such as pipes, vehicles, and other objects. A typical laser scan requires a minimum of five minutes per scan. Focus points (targets) are Figure 1: A 3D Image of a tank externally positioned in and around the tank at different levels and locations within the scanned area. Targets are used as guides to merge individual scans. A minimum of three common targets should be used to ensure accurate overlap of the scans when they are merged, but a larger number of targets will ease the merging process. Internal and external scans can also be merged, again requiring a minimum of three common focus points between internal scans and external scans. The resulting data is then merged using specially designed application software, resulting in a true 3D rendering of the tank. Accurate measurements between objects can then be calculated from the 3D image. Figure 2: A 3D Image of the tank with internal components THE ADVANTAGES OF 3D LASER SCANNING The data collected from a 3D laser scan can be used to calculate tank plumpness, out-ofroundness, settlement, and other situations requiring detailed measurements. Data can be evaluated or reevaluated after the scan technician has left the tank site, and can also be evaluated for other purposes without an additional site visit or an additional round of measurements. In the future, 3D scanning software applications are expected to support the production of strapping and calibration charts in real time, thereby eliminating delays in tank assessment. In addition, software enhancements are expected that will provide accurate floor mapping and exact patch locations,

6 Page 6 a significant improvement over current manual mapping methods. It is important to note that accurate laser scanning depends on calculating the time it takes reflected light to return from an object to a scanner. The effectiveness of the scan is compromised if the object or area being scanned absorbs light, or if the laser is refracted at an angle at which no data can be collected. The distance limitation is 80 meters (approximately 266 feet). CONCLUSION 3D laser scanning technology offers significant advantages in the evaluation of above-ground storage tanks. It can provide a detailed assessment of a tank shell and tank bottom for deformations and tank settlement, allowing for a more accurate finite element analysis of the area. 3D laser scanning can also be used for tank calibrations to ensure that measured volumes account for the full surface of the tank shell and bottom, including all deformations. Finally, specialty software applications provide effective and efficient comparisons between multiple scans, easing the task of evaluating tank changes over time. PetroChem Inspection Services provides 3D laser scanning services and evaluation in support of a variety of above-ground storage tank applications. For additional information about our capabilities, visit our website at com/industry/petrochem.cfm, or contact us at An Overview of Pipes and Tubing Inspection Techniques than ferrous materials. However, eddy current technology is sensitive to a large number of variables, and can be 3-4 times more efficient than other inspection methods. These benefits make eddy current testing a tool of choice for many inspection applications. From heat exchangers, condensers, and boiler tubes to process coders and chillers, pipes and tubing are critical components in a wide range of petrochemical production and refining operations. As such, the routine inspection and maintenance of pipes and tubing is an essential task, as it helps to minimize production shutdowns, reduces the risk of environmental leaks and spills, and increases worker safety. There are a variety of nondestructive testing techniques available to assess the integrity of pipes and tubing. Techniques include Eddy Current Testing, Remote Field Eddy Current testing (RFT), Magnetic Flux Leakage (MFL) testing, Internal Rotary Inspection System (IRIS) testing, and Laser Optical Tube Inspection System (LOTIS) Testing. The type of testing selected for a specific application typically depends on the magnetic properties (ferrous or non-ferrous) of the pipe or tubing subject to evaluation, as well as the relative cleanliness of the pipe or tubing. The following sections summarize each of the above techniques and their application in field assessments. EDDY CURRENT TESTING Eddy Current Testing uses bobbin type probes to induce electrical currents into pipe and tubing materials. As the probe is guided through the pipe or tubing, material defects, such as cracks, pitting, and wall degradation disrupt the flow of the electrical current, thereby signaling a problem. Advanced eddy current testing systems can filter out unwanted responses, improving the overall quality of an inspection. Eddy Current Testing is typically used with nonferrous materials, since they are less permeable REMOTE FIELD EDDY CURRENT TESTING Remote field Eddy Current Testing uses a special type of amplifier and probe that produces the higher power fields required for the testing of pipes and tubing made of ferrous or carbon steel materials. Because remote field eddy currents are transmitted through the wall of the pipe or tubing, it is capable of detecting defects on both the inside and outside diameters, although accuracy decreases as the cross section of the tube increases. Like Eddy Current Testing, remote field eddy current testing is less dependent on the cleanliness of the pipe or tubing. However, remote field eddy current testing is slightly less efficient than conventional eddy current testing, since the speed at which testing is conducted must be as constant as possible in order to obtain the most accurate data. MAGNETIC FLUX LEAKAGE TESTING Magnetic flux leakage testing uses a strong magnet inside the inspection probe. When

7 Page 7 traveling through a section of pipe or tubing, the magnetic probe detects wall defects and other discontinuities due to variations in flux distribution generated by the probe. Magnetic flux leakage testing is best used on ferrous or carbon steel materials, and is less effective with aluminum pipes and tubing. INTERNAL ROTARY INSPECTION SYSTEM TESTING Internal rotary inspection uses an ultrasonic beam to scan the entire length of a tube s internal service, monitoring echoes from the tube s front and back walls to produce precise measurements of the tube wall thickness. However, measurement precision is compromised when inside or outside diameter deposits are present, or when pipes or tubing are not extremely clean. For this reason, internal rotary inspections are typically preceded by soda blasting of the pipe or tubing targeted for inspection. Internal rotary inspections often take two to three times longer than comparable remote field Eddy Current Testing. In addition, internal rotary inspections are not as sensitive as other inspection methods to certain types of degradation, such as cracking. It is recommended that degradation and other anomalies identified by internal rotary inspection be verified and confirmed with other inspection methods before repair or replacement of pipe or tubing is undertaken. LASER OPTICAL TUBE INSPECTION SYSTEM TESTING A final method for inspecting tubes and piping is laser optical tube inspection. This technique uses light generated by a laser probe to create a digital image of the tube, which can then be evaluated and analyzed. However, the accuracy of a laser optical tube inspection depends on a high degree of tube cleanliness, and requires that the tube be free of moisture. Otherwise, deposits and moisture will compromise the quality of the data collected. As such, laser optical tube inspection is the least efficient of the inspection methods discussed here. COMPUTER-BASED TOOLS TO ENHANCE INSPECTION TECHNIQUES Computer software used to process data generated by the inspection methods discussed above has advanced significantly in recent years, increasing the overall value of pipe and tubing inspections and also driving further improvements in inspection methods. Now, large volumes of data can be captured, stored, and evaluated, even at the site of inspection, allowing for more detailed examinations in real time. Data from multiple inspections can also be more easily compared and correlated, allowing the inspector to identify trends and potential condition problems in advance. Additionally, inspection reports can be quickly generated, using standard templates or customized report formats. CONCLUSION Today s nondestructive testing and inspection methods have significantly improved the practice of pipe and tubing inspection, making the inspection process more efficient as well as more accurate. Combined with advanced software applications, pipe and tubing inspection technologies have reduced inspection-related production downtime and increased the value of the overall inspection process. These benefits support operator efforts to improve the reliability of operations and to minimize risks to worker safety and the environment. PetroChem Inspection Services is a leading provider of nondestructive testing services for the inspection and evaluation of pipes and tubing used in petrochemical production and refining facilities. For additional information about NDT capabilities, visit our website at nondestructivetestingservices. Your PetroChem contacts worldwide: Americas PetroChem Inspection Services, Inc. Toll-free: Fax: info@tuvam.com Web: Europe TÜV SÜD Chemie Service GmbH Phone: beate.seiss@tuev-sued.de Web: DISCLAIMER All reasonable measures have been taken to ensure the quality, reliability, and accuracy of the information in this newsletter. However, TÜV SÜD is not responsible for the third-party content contained in this newsletter. TÜV SÜD makes no warranties or representations, expressed or implied, as to the accuracy or completeness of information contained in this newsletter. This newsletter is intended to provide general information on a particular subject or subjects and is not an exhaustive treatment of such subject (s). Accordingly, the information in this newsletter is not intended to constitute consulting or professional advice or services. If you are seeking advice on any matters relating to information in this newsletter, you should where appropriate contact us directly with your specific query or seek advice from qualified professional people. The information contained in this newsletter may not be copied, quoted or referred to in any other publication or materials without the prior written consent of TÜV SÜD. All rights reserved 2013 TÜV SÜD America Inc. PetroChem Technical industry e-news updates essential to your operations