MATCOR’s Ted Huck presented a virtual keynote at CORCON 2021. Over 300 corrosion industry professionals connected at the NACE Gateway India Section’s 2021 Virtual CorCon Conference. The primary discussion was around the impact of AC Corrosion Mitigation criteria on the design and operation of cathodic protection systems.
Historically, DC cathodic protection systems are designed to meet specific polarization requirements. The CP system delivers sufficient current to assure that the entire length of the pipeline meets the polarization levels required. Little consideration is given to DC current density, other than to provide a guideline for sizing the CP system.
The actual operation of the CP system is dictated by the amount of current required to polarize the pipeline.
In practice, this often results in operating the CP system by pushing enough current to properly polarize the pipeline to the farthest distance possible from the CP station. Testing is entirely based on these polarization levels. This includes confirmation testing via close interval potential surveys (CIS).
The AC Mitigation criteria has a stringent requirement if the system’s DC current density is not monitored and controlled. However, if the pipeline’s CP system current density is both monitored and controlled, the requirement is less stringent.
This linking of AC Mitigation Criteria to a DC current density value (that historically has never held any significance) represents a significant change in how CP systems must be designed, monitored, and controlled.
For information about MATCOR AC mitigation solutions, please contact us at the link below, or reach out to your local MATCOR account manager.
Over the past couple of years, MATCOR has invested significantly in new equipment including vertical and horizontal drill rigs, water trucks, Mud Puppy™ drilling mud management systems, hydrovac excavation equipment and other support equipment. But MATCOR is also investing heavily in adding talented people to continue to propel our growth initiatives.
Angie has joined MATCOR as our newest Gulf Coast Account Manager working out of our Houston office. She is a 30-year CP industry sales professional with extensive CP product knowledge. She is passionate in supporting and advocating for her clients, understanding their current challenges, and helping to fuel successful outcomes.
Mario has joined MATCOR as a Project Manager to support our fast-growing Permian office in Midland, Texas. He is a certified PMP project manager professional with 9 years of industry experience working for several cathodic protection companies. He has an electrical engineering degree and brings a tremendous amount of enthusiasm and competence to MATCOR.
Cody is another experienced corrosion professional who has joined MATCOR and will be working as a Project Manager out of our Casper, Wyoming office. Cody is a U.S. Army veteran, who spent some time in the drilling and exploration side of the oil and gas industry before transitioning into operations. He has worked for several operators, including most recently at Silver Creek Midstream, where he was a corrosion program manager. As a previous MATCOR customer, he brings a valuable owner/operator perspective to MATCOR and the project management role.
Have questions or need a quote for cathodic protection or AC mitigation materials or services? Contact us at the link below. For immediate assistance, please call +1-215-348-2974.
MATCOR is pleased to announce that we have partnered with LineVision, a Massachusetts based technology company, to provide their innovative overhead transmission line monitoring technology to the pipeline industry as part of MATCOR’s comprehensive suite of AC Interference and Monitoring services.
LineVision’s PACT® (Pipeline AC Threats) system is a patented, self-contained, solar powered utility power line remote monitoring solution that provides pipeline operators with critical information regarding the operation of high voltage transmission lines owned by the power utility company. These innovative power line sensors provide critical data to operators without relying on the power company to provide it.
The ability to independently monitor critical transmission line information can greatly reduce the time required for modeling and eliminate any need for guesswork or assumptions when utility data is not readily available from the power company. Information obtained from the power line sensor includes: • HVAC current being transmitted • Phase order information
For AC Interference Modeling efforts, we can temporarily install this overhead line monitoring solution along the right-of-way (ROW) in strategic locations. This allows us to collect representative data over a period of time to provide the necessary inputs for the AC modeling software.
The LineVision PACT transmission line monitoring equipment can also be incorporated into your AC mitigation system monitoring program to provide information on the actual HVAC line usage. This is especially helpful when understanding how the line’s power flow usage level varies—the PACT system provides alerts if the usage increases over time.
This information, combined with your AC Test station AC and DC current density data trends can help to provide a more accurate picture of your mitigation system’s compliance with the AC mitigation criteria as detailed in NACE SP 21424-2018. This standard requires demonstrating that your system is mitigating to the required criteria level on a time averaged basis, and that it accounts for variations that could impact mitigation. Monitoring the AC transmission power flow is one of those variables.
Have questions about the LineVision PACT technology, or need a quote for AC mitigation services? Contact us at the link below. For immediate assistance, please call +1-215-348-2974.
Chalfont, PA (April 2018) – MATCOR, Inc., the trusted full-service provider of proprietary cathodic protection products, systems, services and corrosion engineering solutions announces that senior engineer and pipeline practice lead Jeffrey L. Didas has been elected to the position of president for NACE International (NACE), the Worldwide Corrosion Authority. His term as president is one year commencing at the close of the NACE Corrosion Conference & Expo 2018, taking place April 15-19 in Phoenix, Arizona.
As NACE president, Didas will advise, govern, oversee policy and direction, and assist with the leadership and promotion of NACE International to support the organization’s mission. He will also serve as chairman of the executive committee and an officer of the association. His responsibilities will include presiding at all official functions of the board of directors and executive committee, including the annual membership meeting of the association and the annual NACE banquet. This position is part of Didas’ five-year commitment to NACE following previous roles as vice president elect and vice president. Following his term as president he will serve one year as past president and one year on the nominating committee.
“I look forward to serving NACE as president over the next year,” said Didas. “My focus will be on member engagement, retention and benefits, moving forward with the strategic plan and our vision for NACE 2030, and promoting the groundbreaking corrosion industry IMPACT Study.”
Didas, an industry expert sought worldwide and active NACE member since 1975, has 44 years of diverse corrosion experience working for pipeline and energy company owner-operators and most recently for MATCOR.
Prior to his executive leadership roles, Didas held a variety of national NACE positions including:
Treasurer of NACE International, the NACE Foundation and the NACE Institute
Director of the Member Activities Committee – MAC
Committee chair for several technical exchange groups (TEGs), including the Corrosion Control Coordinating Committee (TEG 022X), Pipeline Crossings: Steel-Cased, Thrust-Bored, and HDD TEG 208X) and Steel-Cased Pipelines (TG 012)
Technology coordinator for technology management group TMG C1 – Corrosion Prevention and Control for Concrete, Land Transportation and Coating Technology
Vice chair of the NACE Institute Policy & Practices Committee
Member of the Technical Practices Committee – TPC/Technical Coordination Committee – TCC since 1978
He has also served as chair, vice-chair, and general member of several administrative committees over the past 44 years.
Didas received the NACE Brannon Award in 2014 and the NACE Distinguished Service Award in 2001 for his many contributions to the organization. He also received the Appalachian Underground Corrosion Short Course (AUCSC) Colonel Cox award in 2010.
Didas holds the highest level of NACE certification as a Corrosion Specialist and a number of other NACE certifications, including Cathodic Protection Specialist, Coatings Specialist, Chemical Treatment Specialist, Senior Corrosion Technologist, Corrosion Technologist, Corrosion Technician and Level 3 Certified Corrosion Inspector. In addition he is a SSPC (Society for Protective Coatings) certified Protective Coatings Specialist.
Didas graduated from Thomas A. Edison State University in Trenton, NJ, with a BSET in Electrical Engineering. He acquired his ASEE in Electronics Technology from Springfield Technical Community College in Springfield MA.
NACE International, The Worldwide Corrosion Authority, serves nearly 36,000+ members in 130 countries and is recognized globally as the premier authority for corrosion control solutions. The organization offers technical training and certification programs, conferences, industry standards, reports, publications, technical journals, government relations activities and more. NACE International is headquartered in Houston, Texas, with offices in San Diego, California; Kuala Lumpur, Malaysia; Shanghai, China, Sao Paulo, Brazil and Al-Khobar, Saudi Arabia.
Introduction: Addressing Aging Pipelines and Pipeline Coatings
External corrosion is one of the significant threats facing pipeline operators worldwide. Historically, pipeline owners have employed a two-tiered approach towards mitigating corrosion risks. The primary defense against corrosion has been to apply a pipeline coating system that acts as a barrier, protecting the steel pipe from its environment. Cathodic protection is employed to supplement the coating system by providing protective current to the holidays or defects within the coating system. As with any aging structure, however, time takes its toll – for older pipelines this often results in an older coating system that starts to degrade in its primary function of protecting the pipeline from its environment.
This paper addresses the fundamental issue that many operators will face when evaluating their aging pipelines and pipeline coating systems. That issue is, quite simply, what is the best strategy to remediate an aging pipeline with deteriorating coating systems to maintain compliance with international standards for pipeline integrity. The options are to improve/upgrade the cathodic protection system, recoat the pipeline, or replace the pipeline. Each of these options will be discussed in detail and a decision matrix will be provided to facilitate the operator’s decision-making process.
Pipeline Coating Systems
Coating systems have been used on buried pipelines during the last hundred years and the technology continues to be the subject of significant research and innovation. Pipeline coating manufacturers are continually searching for better coatings to meet the varied needs of industry. Initially, the coatings were simple mixtures of crude pitches and solvents. These early bitumastic/asphaltic systems evolved into engineered coal tar enamel coating systems, which were prevalent into the 1960’s. The introduction of fusion-bonded epoxies (FBE) in the 1970’s quickly captured much of the pipeline market, although polyethylene, polypropylene and coal tar enamels are still used as well. The coatings industry continues to research and develop improved methods of providing more reliable and more economical coating systems.
When evaluating aging pipelines, coating condition is one of the critical issues that must be addressed. The coating provides the primary defense against pipeline corrosion and as the coating system ages and deteriorates, then the risks of corrosion increase exponentially. One of the challenges that must be addressed by pipeline owners is properly identifying the type and vintage of the coatings along a given pipeline. In many cases, different sections of pipeline may have different coating systems depending on the age of the pipeline and the standards in place at the time a section of pipe was installed.
Another critical consideration when evaluating aging pipeline coating systems is to identify whether the coating system fails shielding or non-shielding. Coating systems that fail in a non-shielding mode do not inhibit the flow of current making cathodic protection a viable alternative when considering how to remediate these lines. Other coating systems, principally tape coating systems, can fail in a manner that shields cathodic protection current and thus greatly reducing the possible remediation methods available.
Modern, over-the-line survey technologies have proven to be quite effective in evaluating coating quality and finding coating holidays. Technologies such as pipeline current mapping (PCM) which utilize a carrier signal transmitted along the pipeline with a receiver measuring the line attenuation along the pipeline length can accurately pinpoint areas of significant coating degradation even under concrete or asphalt. The information gathered using PCM in conjunction with pipe to soil close interval surveys (CIS) and direct current voltage gradient (DCVG) testing form the basis for identifying critical risk areas along aging pipelines. In-line inspection technologies using smart pigs also provide valuable data regarding coating quality.
Pipeline coating systems are typically augmented by the application of cathodic protection. With a well-coated pipeline, cathodic protection can be economically applied to protect the coating holidays and defects by placing discreet anode beds that distribute current over long distances. In many cases ground beds can be located several kilometers apart and still provide sufficient current distribution to protect the entire pipeline. With some of today’s high technology factory applied coatings, the coating efficiencies are exceptionally high and the groundbed output requirements are very low. These discreet ground bed systems can either be deep anode ground beds or shallow ground beds located some distance off the pipeline.
Several issues must be considered when designing a cathodic protection system. These include coating quality, soil resistivity, available locations for electrical power, ground bed right of way issues, accessibility for maintenance, AC and DC stray current interference, and a host of additional issues. What is critical for aging pipelines is the regular evaluation of the effectiveness of the CP system. Frequently, as pipelines age and the coating quality begins to deteriorate, the CP systems are unable to provide sufficient current properly distributed to meet established cathodic protection criteria. In many cases, simply ramping up the output of the existing system or adding additional ground beds does not prove sufficient to address the problem.
Aging pipeline systems with deteriorating coating systems suffer from poor current distribution and are characterized by areas of low potentials and exceedingly high levels of applied current density. The challenge with these pipeline systems is controlling current distribution to achieve the prescribed polarization levels consistent with international standards for adequate cathodic protection.
Figure 1 shows a deep well anode system with current output such that some areas are not meeting required off-potentials of -0.85 Volts to meet NACE criteria.
The typical response to this problem is to increase the overall output of the deep well system (see Figure 2.) This generally does not alleviate the problems of not meeting the off-potential criteria and leads to over-polarizing the piping (potentials greater than -1.2 Volts.) This can result in coating disbondment further exacerbating the problem. The higher output current increases the ground bed’s consumption rate reducing operating life while raising operating costs appreciably. All this occurs without achieving the required levels of polarization to meet cathodic protection criteria.
The next step that is taken to fix the cathodic protection current distribution problem is to add additional ground beds to reduce the distance between point sources. This too, proves to be an ineffective solution as the new ground bed provides only limited additional benefit (see Figure 3.)
The problem cannot be economically resolved by the addition of an ever-increasing number of ground beds applying greater and greater amounts of additional current. The pipeline operator is then faced with a limited number of options: recoat the pipeline, replace the pipeline, or install a linear anode cathodic protection system.
Recoating/replacing is the only viable alternative for pipeline systems utilizing shielding type coatings such as tape wrap systems. Recoating costs typically run several hundred dollars per foot in open right of way areas and can be significantly more expensive in congested urban locations (these are ballpark numbers applicable to the United States and can vary significantly.) Recoating, when properly performed, can restore the pipeline coating system to an as new condition greatly extending the service life of the recoated section. The critical issue is to assure that the recoating is executed by an experienced coatings contractor with rigorous quality controls in place. Pipeline replacement is expensive and only performed when extensive third-party damage, significant corrosion or other extenuating circumstances warrant.
An economically attractive alternative to recoat/replace options is to utilize a linear anode configuration in lieu of point anode systems. This option is only viable when the coating system is non-shielding – this would include asphaltic and epoxy type coating systems. The application of a linear anode system typically costs between $20-30/foot in open right of way (again these are general price guidelines and can vary significantly.) In suburban or urban areas, horizontal directional drilling (HDD) can be an effective installation method with minimal surface disruptions. These linear anode systems eliminate the distribution problems experienced by point anode systems; they are in effect an infinite series of point anodes, which provide an optimum current distribution (see Figure 4.)
In addition to confirming that the pipeline coating system is non-shielding and appropriate for the application of linear anodes, the linear anode system design must take into consideration the critical issue of voltage drop and its affect on current attenuation. Voltage drop can have a significant impact on DC power distribution to the linear anode system. Ideally, rectifiers would be located no further than half a mile to a mile apart, however, practical considerations including availability of AC power, right of way issues and other factors can force this to be extended further complicating the system design and affecting the installed cost.
While the design can be complicated by voltage drop considerations, one of the benefits of a linear anode system is that the power consumption is relatively low. Ground bed resistance, as determined by Dwight’s Equation, is significantly affected by anode length and this results in very low groundbed resistance values for linear anode systems relative to conventional ground beds. This makes the linear anode system much more suitable for low wattage power sources such as solar arrays and thermo-electric generators (TEG’s) than conventional ground beds whose wattage could be two or more times that of a linear anode system to achieve the same current discharge.
Aging pipeline systems with deteriorating coating systems present a difficult challenge to pipeline operators. The more the coating deteriorates, the more difficult it is to distribute current further away from the ground bed. The natural response to ramp up the ground bed output does an inadequate job of throwing current further but does result in increased current flow, higher current densities and over polarization near the ground bed further stressing the coating system. Adding additional ground beds also allows more current to be applied to the pipeline, but does not alleviate the current distribution issues. Ultimately, pipeline operators are faced with the choice of recoating/replacing the pipeline, or installing a linear anode system. The flowchart below (Figure 5) provides a decision matrix. Note that aging pipeline systems whose coating systems are determined to be in good condition through indirect and direct examination, require additional investigation to determine why criteria is not being achieved.
Did you know that corrosion costs us an astounding 2.5 trillion dollars globally?
Not to mention corrosion can cost lives and jobs…
Today is corrosion awareness day, so we thought it would be a good idea to reiterate the importance of the NACE IMPACT (International Measures of Prevention, Application, and Economics of Corrosion Technologies) study released in 2016.
According to the study, most corrosion failures, and nearly all catastrophic corrosion failures are preventable. And nearly $875 billion can be saved through the right prevention and risk analysis efforts.
Through the IMPACT study, NACE determined that in order to reduce the astronomical cost of corrosion, we would have to change how decisions are made regarding corrosion. We must not only continue to develop corrosion control methods and technology, but we must utilize organizational management systems and risk tools throughout all levels of an organization to achieve the greatest success in saving lives, jobs and money.
MATCOR to Present on Impressed Current Linear Anode Cathodic Protection at NACE UAE Corrosion Conference in Abu Dhabi
Chalfont, PA (April 27, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions will present a paper exploring the use of flexible impressed current linear anodes to minimize current densities for a wide range of cathodic protection applications at the annual NACE UAE Corrosion Conference held at the St. Regis in Abu Dhabi, United Arab Emirates May 12-14, 2015.
The presentation explores flexible impressed current linear anode cathodic protection that extends the benefits of linear anodes for various CP applications. To minimize current distribution challenges, the linear anodes are designed utilizing multiple internal connections, which provides redundancy and protection against uneven anode consumption, minimizes current densities and allows placement in close proximity to the structure. The linear anode is simple to install, requiring only a small trench, and is ideal for congested areas and tight spaces. See below for the complete abstract.
ABOUT THE AUTHOR
Shailesh Javia serves as International Director for MATCOR and has over 22 years experience focused on corrosion engineering and cathodic protection. His diverse knowledge and experience includes designing cathodic protection systems, managing turnkey CP projects and conducting commissioning surveys for cross country and city gas pipelines, tanks and vessels, tank bottoms, and industrial facilities including fertilizer, petrochemical and power plants, and refineries. Mr. Javia is a certified NACE Cathodic Protection Technologist, has successfully completed the NACE Direct Assessment Course and has presented several papers at NACE and ASME conferences.
ABSTRACT: Applications of Impressed Current Linear Anodes in Cathodic Protection
Flexible impressed current linear anodes can extend the benefits of linear anodes to a wide range of cathodic protection applications. Tight spaces, high traffic areas, poorly coated pipelines, new construction tank bottom, tank bottom retrofits, reinforcing steel-in-concrete, sheet pile walls or inside large diameter pipes – are all good examples of linear anode cathodic protection applications.
Linear anodes handle current distribution challenges by minimizing current densities, in addition to placement in close proximity to the structure being protected from corrosion. Innovative design utilizing multiple internal connections provides redundancy, protects against uneven anode consumption and minimizes voltage drop.
Linear anodes can simply be laid alongside a new pipeline; cable plowed next to an existing pipeline, or installed utilizing horizontal directional drilling (HDD) under an existing structure. Linear anodes require only a small trench for installation, ideal for congested areas and minimizing landowner “right of way” issues.