Category Archives: Anodes

Matcor Earns Patent for Iron Gopher® Linear Anode

Iron Gopher® is only linear anode designed for cathodic protection in horizontal directional drilling applications

KENNESAW, Georgia, Sept. 19, 2018 — MATCOR, a BrandSafway company, recently earned a design patent for its Iron Gopher®, a linear anode designed to prevent corrosion through cathodic protection in horizontal directional drilling (HDD) applications. With a braided stainless steel jacket for linear anode protection during installation and a built-in pulling loop for connecting to the drilling head, the Iron Gopher provides approximately 200 percent more pulling strength than traditional anodes used in HDD applications.

It is available in standard and dual-end models, which can both be connected to a DC power source for active cathodic protection with a current. The standard model is used for most cathodic methods, such as roads, streams and property crossings, and the dual-end model is typically used under tank operations or anywhere it is not possible to connect both ends of the linear anode.

“We developed the Iron Gopher with installation costs and timelines at the forefront, focusing on strength to reduce the risks associated with the linear anode breaking during installation,” said Ted Huck, one of the Iron Gopher inventors and vice president of technical sales for MATCOR. “It also makes job sites—and utilities and pipelines—safer by using cathodic protection to decrease the chance of failure due to corrosion that could cause gas leaks or other potentially catastrophic events.”

The Iron Gopher was invented by Ted Huck; William Schutt, MATCOR founder; and Knut Fenner, former director of business development at MATCOR.

“MATCOR is an innovation leader in the corrosion and cathodic protection industry with its ongoing R&D, proprietary products, service and client-focused cloud technology,” Bob Burns, president of Midstream said. “The Iron Gopher is just another example of how we are continually raising the standards within the corrosion industry and ultimately providing the best solutions to our clients.”

For more information about Iron Gopher, visit matcor.com/products/matcor-iron-gopher.

About MATCOR

MATCOR, Inc. is a BrandSafway company and a leading cathodic protection and corrosion prevention engineering design firm, providing environmentally beneficial systems and services to global clients for more than 40 years. An ISO 9001:2015 certified expert in the field of cathodic protection, MATCOR offers proprietary corrosion protection design, engineering, manufacturing, installation, cathodic protection testing, annual surveys, maintenance and complete corrosion protection project management. MATCOR specializes in protecting the infrastructure of the oil and gas, utility, transportation and construction industries. To learn more about MATCOR, please visit www.matcor.com or call 1-800-215-4362.

About BrandSafway

With a commitment to safety as its foremost value, BrandSafway provides the broadest range of services, products and solutions, with the greatest depth of expertise, to the industrial, commercial and infrastructure markets. A portfolio company of Clayton, Dubilier & Rice, BrandSafway offers access, industrial services and forming and shoring solutions to more than 32,000 customers through a workforce of approximately 35,000 employees, who support our network of 350 strategic locations across 30 countries. With its global footprint, rigorous operating processes and extensive service offerings — a full range of work access, insulation, coatings, specialty industrial services and forming and shoring solutions — BrandSafway supports customers’ maintenance and refurbishment needs as well as new construction and expansion plans. Today’s BrandSafway — large enough to leverage economies of scale to increase safety and productivity, while also remaining nimble and responsive — delivers unmatched service with local labor and management.

Anode Current Ratings and Soil Resistivity

We appreciate the question: “How does soil resistivity impact current rating.”  The short answer is that resistance has nothing to do with anode rating. Here is a more detailed response:

  1. Anode current rating – all anodes have a current rating based on how long they can be expected to operate at a given current rating.  All anodes have some defined expected life based on current output and time – so many Amp-Hours of service life.  For example a magnesium anode may have an expected consumption rate of 17 lb/Amp-year (7.8 kg/amp) so if a 17 lb anode is operated at 0.1 amps it would have a life of 10 years.  For MMO anodes, they too have an expected life.  For our linear anode rated at 51 mA/m it is important to know that that rating is actually 51 mA/m for 25 years.  So a 100m anode segment with this rating would have an expected life of 127.5 Amp-years.  If this anode were operated at 5.1 amps (full rated capacity) it would be expected to operate for 25 years.  IF it were operated at 2.55 amps (50% of rated capacity) it should last 50 years.  The anode life is generally linear.  Please note that resistance has nothing to do with the anode current rating – the anode current rating merely calculates the life of the anode as a function of how many amps for how long of time.
  2. Actual current output – just because you install an anode rated for 5.1 amps for 25 years (our 100m segment of 51 mA/m SPL-FBR) does not mean that the anode will output this amount of current.  It just means that at that current rating you can expect 25 years of life.  The anode is merely one component of the overall cathodic protection circuit.  The actual output of the anode is function of Ohms Law ( Voltage = Current * Resistance).  It would make sense to note that if the system Voltage were zero (the rectifier were turned off or disconnected) then the anode would not have any current output.  Likewise if the 100m anode segment were installed in a very low resistance environment and driven by a powerful rectifier, the current could be much higher than 5.1 amps which would result in a much shorter life.
  3. Why anode rating is important to the CP designer – the CP designer is tasked with protecting a specific structure for a given period of time (protect this pipeline for 30 years.)  The CP designer then calculates, based on actual testing or established guidelines, the amount of current that should be sufficient to achieve appropriate CP levels to protect the structure.  This results in an answer of some number X of amps required.  If the requirements are to protect the structure for Y number of years, then the anode life required is X * Y (# of amps times # of years).  This defines the minimum amount of anode life that is needed.
  4. The next question the CP designer must address, once it is determined how much current is needed, is how to design a system that will generate that amount of current.  Since Ohms Law dictates that Voltage = Current * Resistance (V=IR) then if we know that the Current = Voltage/Resistance (I=V/R.)  Thus the CP designer must understand how to calculate system resistance (R) and must provide sufficient driving force (V)  Several factors affect system resistance (R) including anode geometry – the longer an anode, the lower its resistance – which in many applications is a big benefit to the linear anode.  One of the great benefits of the linear anode is that because of its length, in most applications the soil resistivity plays a lesser role since the anode resistance to earth is generally low for a wide range of soil resistivities due to its length.  For extremely high resistance environments, linear anodes may be the best option since short anodes will not have a low enough resistance.
  5. There are other factors that go into CP design including current distribution and making sure sufficient current is being applied across the entire structure.

CP Design can be very complicated.  I hope that the above explanation is helpful, but if there is a specific application to evaluate, please contact us with the details.  We are also available, for a reasonable engineering fee, to develop and/or review CP system designs.

Ted Huck

VP, Technical Sales

6 Sled Anodes Replace 274 Galvanic Anodes for Marine Jetty Corrosion Protection

Marine environments can be some of the harshest environments on the planet for corrosion of steel structures. Indeed, the earliest application of cathodic protection can be traced back to Sir Humphrey Davy and the British Navy’s investigation into corrosion on copper sheathed wooden vessels. This video demonstrates MATCOR’s impressed current sled anodes that are successfully being used to protect steel piles for jetties, docks and other similar steel structures in marine environments.

At 1:03 in the video, we demonstrate how the marine anode sled operates with a trade show model.

Sled Anode
Sea-Bottom™ Anode Marine Sled Anode

At 4:05 you see a MATCOR Sea-Bottom Marine Anode Sled being lowered into the water as part of the cathodic protection system protecting a steel jetty structure in Indonesia. The jetty is constructed with four interior rows of concrete piles and an exterior row of 247 bare metallic piles. The operator initially considered galvanic anodes to protect the jetty from corrosion – until they compared the cost, time and effort to install the required 374 aluminum anodes each weighing 200 each. Instead they opted for six marine anode sleds, taking only three days to install.


For assistance with near shore marine anode systems, please CONTACT US.

Selecting the Correct Linear Anode for Horizontal Directional Drilling (HDD) Installation

As the world’s leading manufacturer of linear anodes, and the only manufacturer of a linear anode specifically designed for use with horizontal directional drilling installations, we thought it would be appropriate to discuss various anode options for HDD installation.

Can any linear anode be used in conjunction with horizontal directional drilling?

An engineer’s favorite answer to any question is “It depends” and this is certainly the case with HDD installations. The important thing to note is that when attempting to pull a linear anode through a bore hole, there is a chance that the pulling forces on the anode will exceed the strength of the anode and cause the anode to break. Even if the anode does not break completely, stretching of the anode can weaken or damage the internal header cable or anode to cable connections.

There are a lot of variables that can impact the success of any linear anode HDD installation. The short answer is yes, with the right bore hole, any linear anode can be pulled successfully. Conversely, with the wrong bore hole, any linear anode can be pulled apart during installation.

What are the key factors to consider when planning an HDD linear anode installation?

The key factors include a site geotechnical investigation, terrain and route mapping, and bore planning.

Site Geotechnical Investigation

Any discussion about HDD installation planning starts with a site geotechnical investigation. Obtaining a geotechnical survey or as much geological information about the respective jobsite is very important. A great amount of record information is available through sources including:

  • United States Geological Society (USGS)
  • National Geological Map Database
  • Publications of the US Army Corps of Engineers
  • Earth Explorer
  • The National Soil Survey Center (NSSC) a division of the US Department of Agriculture
  • State Departments of Transportation
  • Highway Administrations
  • Original construction records

In addition to record information, site-specific investigations (soil bores and soil sampling) by trained geologists and geotechnical service companies can provide valuable detailed data on the planned bore area geology.  The geotechnical analysis should identify several relevant items including:

  • Soil identification along the bore route to locate rock, rock inclusions, gravely soils, loose deposits, discontinuities and hardpan
  • Soil strength and stability characteristics
  • Groundwater

Local drillers with experience in the identified area can often provide valuable insight based on similar projects in the same area.

Terrain and HDD Route Mapping

Collecting accurate topographical information of the bore route is another critical component in the planning phase.  Terrain and HDD mapping includes determining HDD bore hole entrance and exit locations, identifying and mapping elevation profile changes, ensuring that other utilities are appropriately identified and avoided, assessing the need for traffic control, evaluating any environmental considerations or limitations that might impact the use of drilling muds and hole conditioners.

Bore Planning Software

Several commercial bore planning software tools are available to assist in the planning phase.  These programs utilize the soil and geotechnical data combined with the terrain and route mapping information to provide a graphic visualization of the job helping the driller more accurately “see” and perform the job from start to finish.  These software tools help the contractor select the appropriate drill rig, drill bit type and back reamer based on the anticipated soil conditions and the total bore length.  By choosing the drill stem and length, the desired bore path depth, desired minimum cover, diameter and bend radius of the product being pulled, the software plots a proposed bore pitch, calculates setback distances, figures point to point bore paths, estimates hole volumes and calculates pullback time. The software can also provide a fluid–mixing process map that shows how much mud should be used based on soil conditions, drill unit and tooling used.

If a bore planning software package is not used, field calculations should be performed to appropriately choose the correct drill rig, drill bit and back reamer tooling requirements, desired bore path and quantity and type of drilling fluids to be utilized.

What anode should be selected for HDD installation?

MATCOR’s SPL-FBR™ Linear Anode may be suitable for some HDD installations.

MATCOR manufactures two linear anode products (SPL-FBR™ Linear Anode and the Iron Gopher™) that are both, in the right circumstances, suitable for use in HDD installations.  The installation contractor, along with the client, must carefully select the appropriate anode and the appropriate anode installation methodology.  The two generally accepted methodologies are direct pulling of the anode through the properly conditioned borehole by attaching the anode to the backreamer after the initial pilot hole has been drilled.  The second installation methodology involves pulling an HDPE pipe sleeve into the borehole, installing the anode inside the pipe, and then removing the HDPE sleeve.  The tables that follow are intended to assist the installer in selecting the appropriate anode and installation methodology.  The selection of the appropriate anode type and installation methodology is subjective based on a qualitative analysis.

Iron Gopher® Linear Anode for HDD Applications

TABLE 1 – Linear Anode Application Difficulty

EASY• Less than 200 foot pulling length
• Minimal changes in elevation
• No environmental restrictions on use of drilling muds/hole conditioners
• Installation costs and risks are low
MODERATE• 200-500 foot pulling length
• Moderate elevation change
• No environmental restrictions on use of drilling muds/hole conditioners
• Installation costs are modest and risks are low
DIFFICULT• 500-1000 foot pulling length
• Moderate elevation changes
• Some environmental restriction on use of drilling muds/hole conditioners
• Installation costs are higher and risks are moderate
EXTREME• 500+ foot pulling length
• Extreme or multiple elevation changes
• Restrictive environmental limits on use of drilling muds/hole conditioners
• Critical application with high costs and risks

TABLE 2 – Anode Selection Guidelines

 Linear Anode Application Difficulty 1
SOIL TYPE 2EASYMODERATEDIFFICULTEXTREME
Earth LoamsFBRFBR/Iron GopherIron GopherIron Gopher*
Sand/SiltFBR/Iron GopherIron GopherIron GopherIron Gopher*
ClayIron GopherIron GopherIron Gopher*Iron Gopher*
Gravel / CobleIron GopherFBR*/Iron Gopher*Iron Gopher*Iron Gopher*
RockyFBR*/Iron Gopher*FBR*/Iron Gopher*Iron Gopher*Iron Gopher*

*Anode is to be installed in HDPE sleeve that is then removed

NOTES
1Classifying the linear anode application difficulty using Table 1 is a qualitative analysis and may warrant taking into consideration other risk factors that may be appropriate. In general, the more difficult the application, the more costly the installation component, the greater the case to use the higher pulling strength Iron Gopher and the greater the incentive to use temporary HDPE sleeving to assure the lowest risk installation.
2Soil Types based on the US Department of Agriculture Soil textural classification guidelines. Earth Loams would include the broad range of Sandy Clay Loam, Loam, Silt Loam, and Clay Loam.

What contingency planning is warranted for an HDD installation?

Even with proper project planning and an experienced installation contractor, some consideration should be given to contingency plans if something unforeseen happens during the HDD boring and anode installation.

  • Are alternate bits available if needed to complete the pilot hole?
  • Is a larger boring machine available if needed?
  • If drilling is more challenging than anticipated, do we have ready access to HDPE pipe for sleeving if warranted?
  • Does the project warrant having one or more spare anode assemblies in the event of an anode breakage during installation?

While these risks can be greatly minimized with proper planning, asking these questions before mobilizing to the site can help solve problems more quickly, saving time and money.


For assistance with linear anode selection for HDD applications, MATCOR’s linear anode systems, project management or installation, please CONTACT US.

Sled Anode Cable Connections

What is the best way to prevent damage to sled anode cable connections due to rough sea current and waves?

MATCOR marine sled anodes (Sea-Bottom™ Anodes) are designed with the cable connections routed inside a high density polyethylene (HDPE) protective pipe with holes to provide a level of mechanical protection. Then we use concrete weights to help secure the HDPE pipe (with the cable inside) to the sea bottom so that they are not subject to wave or tidal action.

Sled Anode Cable ProtectionThe protective housing is pictured here and called out as item 4 on the drawing on page 3 of our Sea-Bottom Marine Anode Sled brochure. For the concrete weights, you can use a variety of methods from sacks of concrete to custom formed concrete cast weights. Below is a photo of the weights that were locally supplied to us for a recent project in Indonesia. These weights are installed by divers during the sled anode installation.

sled anode concrete weights

For assistance with impressed current anode system design, MATCOR’s Sea-Bottom Marine Anode Sleds, project management or installation, please contact us at the link below.

Contact a Corrosion Expert

Impressed Current Anode Systems for Jetty Piling

One of the key decisions for any cathodic protection system design is the choice between an impressed current anode system or a galvanic (or sacrificial) anode system. This is especially true for marine applications where cathodic protection is commonly applied to structures such as steel piling systems on jetties and piers for corrosion protection. A recent MATCOR project highlights the choice between ICCP and Galvanic systems on a newly constructed jetty in Surabaya, Indonesia.

Impressed Current Anode Systems vs Galvanic Anode Systems

impressed current anode systems for jetty piling
Click on the image above to read the full case study comparing impressed current cathodic protection utilizing marine anode sleds with a galvanic anode system.

This case study article, which appeared in the October issue of Materials Performance includes a comparison of key factors for commonly used galvanic (aluminum) anodes and impressed current (titanium with mixed metal oxide) anodes. The key differences between an impressed current anode system and a galvanic anode systems include:

  • Anode consumption rates
  • Current density (CD) limits
  • Driving voltage
  • Anode quantities
  • Installation time and costs

The article describes these key differences in more detail.

Conceptual Design – Galvanic vs Impressed Current

Jetty applications can be designed using either galvanic anodes or impressed current anodes, and often it is a matter of client or designer preference. For this project in Indonesia, the cathodic protection designer reviewed both system types to determine the ideal design for this application based on a 30-year anode life. The final decision was based on several factors including total number of anodes and installation time required, in addition to safety considerations.

Impressed Current Anode System Installation and Commissioning

The final design called for the installation of six marine anode sleds, which took less than a week to complete.

For more details about this impressed current anode system solution for jetty piling cathodic protection, please read the full article in the October issue of Materials Performance. You can also access the full article HERE.

For assistance with impressed current anode system design, MATCOR’s Sea-Bottom Marine Anode Sleds, project management or installation, please contact us at the link below.

Contact a Corrosion Expert

MATCOR Receives Patent for SPL-SandAnode™

Cathodic Protection Anode Designed Specifically for Tank Bottom Replacement Applications

MATCOR was recently issued US Patent No. 9,410,253 for its SPL-SandAnode, an impressed current linear anode that prevents corrosion of above ground storage tank bottoms (ASTs). Invented by Glenn Shreffler, executive vice president of engineering for MATCOR, the SPL-SandAnode is the only impressed current linear anode designed specifically for tank bottom replacement projects. These applications typically have six inches (150 mm) or less of sand where the anode is to be installed.

tank bottom replacement cathodic protection anode
MATCOR’s SandAnode is the only impressed current linear anode designed specifically for tank bottom replacement projects.

The recommended cathodic protection system for most ASTs is a tank ring anode system that utilizes linear anodes in a concentric ring configuration. However, when the clearance between the tank bottom and anode is less than 6-inches (150 mm), the SPL-SandAnode is used, either in the concentric ring configuration or in parallel linear lengths. The prepackaged linear anode with a sand backfill, in lieu of calcined coke, allows the anode to be simply laid out on the foundation while easily maintaining the maximum separation distance of the anode to the tank bottom.

The SPL-SandAnode is one of MATCOR’s SPL™ Anode Series, a complete line of flexible impressed current linear anodes utilizing MMO anode technology to support a broad range of cathodic protection applications. Advantages of MATCOR’s linear anodes include:

  • Single package design
  • Uniform current distribution
  • Flexible cathodic protection system
  • Waterproof Kynex® anode to cable connections

Learn more:  SPL-SandAnode

About MATCOR

MMO Anode Technology: The latest in Cathodic Protection

MMO anode technology has taken over the cathodic protection industry and MATCOR has been on the forefront for the last 20 years. Ted Huck, our VP of International Sales was interviewed at the recent NACE Corrosion Conference. In this video he discusses MMO anode technology for cathodic protection systems and the importance of reliable anode to cable connections.

MMO Anode Technology

MMO anodes, or mixed metal oxide anodes are the latest technology in the corrosion industry. Mixed metal oxide anodes are lightweight and durable with a very low consumption rate. 

MMO anodes are a mix of metal oxide electrocatalysts. In the presence of a DC voltage source they cause an electrical reaction that generates cathodic protection current. Unlike conventional impressed current anodes that physically consume as part of the cathodic protection reaction (at rates measured in kg/amp-year), MMO anodes are dimensionally stable and do not consume. Instead, they have a long and predictable catalytic life. MMO anodes consist of a thin coating of the MMO catalyst over an inert lightweight titanium substrate and are available in a wide range of shapes and configurations.

Why Cathodic Protection Systems Fail

Waterproof Anode to Cable Connection to protects MMO anode cathodic protection systems
Kynex® Patented, Waterproof Anode to Cable Connection

The most critical component to any cathodic protection anode system is the connection of the anode to the cable that runs back to the power supply. Because the cable is part of the anode system, if it has any nicks or defects or is not water tight, that cable can become part of the anode and will very quickly consume. When that happens, the anode fails. So, with cathodic protection systems it is imperative to have the highest quality connections.

Typically, when a cathodic protection anode system fails, it is not the anode that fails, it is the anode connection that fails. MATCOR has developed a proprietary technology for connecting wire anodes to cable, called Kynex®. Wire anodes are the heart of a lot of our products and this proprietary anode technology is a huge leap forward in the reliability of these connections.

Cost-effective, Reliable Cathodic Protection Solutions

At the end of the day, for our clients, it’s all about delivering value. It’s providing a cost effective solution that’s going to serve them for a very long time. As a designer and manufacturer of cathodic protection anode systems, we are able to specifically address client needs with customized corrosion prevention solutions that provide:

  • Long life
  • Great economic value
  • Superior reliability

MATCOR Products and Services

MATCOR is one of the world’s leading cathodic protection companies. We design, manufacture, install and service cathodic protection systems for clients worldwide. MATCOR provides services to the pipeline, midstream and oil & gas industries, protecting assets such as pipelines, storage tanks, and compressor stations. We also do a lot of work in the power industries, petrochemical, and chemical industries. Anywhere where you have buried steel structures, we are there to stop corrosion.
We encourage you to contact MATCOR through our website where our corrosion specialists and engineers can provide a solution tailored to your needs.

3 Cathodic Protection Methods for New Plant Construction

Cathodic Protection for Underground Piping Overview

Cathodic Protection for Underground PipingCathodic protection for underground piping, when applied properly, is an effective means to prevent corrosion. For many underground applications, such as pipelines, cathodic protection system design is relatively straightforward. Plant and facility environments, however, are not simple applications. Plants have congested underground piping systems in a tightly spaced footprint. The presence of copper grounding systems, foundations with reinforcing steel embedded in concrete, conduit, utility piping and structural pilings (either bare or concrete with reinforcing steel) can greatly complicate the task of designing a cathodic protection system.

For simple plant facilities, it is possible to isolate the piping and utilize a conventional galvanic corrosion prevention system. This works only if the plant piping is electrically isolated from other underground structures for the life of the facility. For most plant and facility applications, it is not practical to isolate the piping from the grounding system for the life of the facility. In these cases an impressed current anode system is the only alternative.

3 Methods of Cathodic Protection for Underground Piping and Structures

There are three basic approaches to cathodically protect underground piping and structures using impressed current anodes.

  1. Deep Anode

    One method is the deep anode in which high current capacity anodes are installed from the structure in a deep hole drilled vertically 150+ feet deep. This is analogous to lighting a football field with floodlights.

  2. Shallow Anode or Distributed Anode Bed

    Another method is to use a shallow ground bed anode design where many smaller capacity ground bed anodes are spaced near the intended structures – analogous to street lamps lighting a street.

  3. Linear Anode

    The third method is to place a linear anode parallel to and in close proximity to the piping to be protected discharging current continuously along its length – similar to fiber optic lighting.

This technical bulletin details the advantages of using the linear anode approach for new plant construction projects to protect buried piping in a congested environment. This approach provides the most effective solution both technically and commercially.

Plant and Facility Cathodic Protection Design Issues

Electrical Isolation in a Congested Plant Environment

Electrical isolation is a major concern when designing a CP system for any plant or facility application. Isolating a single cross country pipeline segment from point A to point B is achieved rather simply through the use of electrical isolation flanges/isolation joints that the pipeline operator maintains and tests regularly. The realities of power plant piping networks, on the other hand, significantly complicate electrical isolation. By code, everything above grade in a plant must be grounded, yet it is common to see cathodic protection systems designed based on isolation of the buried piping. Even if electrical isolation is achieved during the plant construction, maintaining electrical isolation over the life of the facility may not be realistic. Given the speed and complexity with which new plants are erected, achieving electrical isolation during construction is no simple task. Once installed, electrical isolation flange kits require regular monitoring and periodic replacement that often does not occur. Piping modifications and other plant maintenance activities can also result in an inadvertent loss of electrical isolation. Cathodic protection for underground piping that relies on electrical isolation should be avoided for plant applications.

Current Distribution – a Critical Issue in Cathodic Protection Design

Another critical issue that must be properly considered during the design of a CP system for plant applications is the highly congested underground environment and the challenges of achieving thorough current distribution. Buried piping is often located in congested underground areas in close proximity to grounding systems, foundations with reinforcing steel, pilings systems, metallic duct banks and other structures that can shield current from the piping systems that are the intended target of plant cathodic protection systems. It is virtually impossible to assess where current will go in a plant environment – the more remote the anode source, the more difficult it is to assure appropriate current distribution.

Stray Current

When discussing current distribution, it is also important to discuss the potential for stray current. For grounded systems, current that is picked up by other buried metallic structures is merely current that is wasted and not available to protect the intended buried piping structures. For isolated metallic structures, such as foreign pipelines, ductile iron piping systems, and nearby facilities or structures, stray current may be a significant concern. Stray current problems occur when current is picked up on an isolated structure and later discharges off that structure and back to a grounded structure. At the location where stray currents discharge, rapid corrosion may be inadvertently induced on the isolated structure.

The Case for Linear Anode Cathodic Protection System Design

The linear anode solution consists of long runs of linear anode installed parallel and in very close proximity to the piping being protected. The current output is kept very low and is generally consistent across the entire system. A linear anode is in effect a distributed system with an infinite number of anodes spaced continually. This system provides the best technical cathodic protection solution and minimizes the current output required as follows:

  • Does not require electrical isolation.
    Because the linear anode is closely located next to the piping being protected, electrical isolation is not a significant concern. The anode is “closely coupled” to the piping and operates with a very low anode gradient that minimizes any losses to nearby structures including grounding.
  • Assures good current distribution as the anode runs parallel to the piping being protected.
    The linear anode cathodic protection system design eliminates any requirement for supplemental anodes to address areas where remote anodes may be shielded after the CP system is commissioned. Wherever the piping goes, the linear anode follows in the same trench. This also makes it very easy to adapt the design during piping revisions that may change the piping system routing as the plant construction proceeds.
  • Eliminates risks of stray current.
    Close proximity to the piping being protected significantly limits current losses to other structures and virtually eliminates shielding and stray current concerns. This also significantly reduces the total current requirements for the system, reducing the rectifier requirements.
  • Access issues – the linear anode is installed in very close proximity to the piping that is to be protected.
    This minimizes the risk of third party damage and reduces trenching required for buried cable. If installed in conjunction with the piping, the anode can be placed in the same trench as the piping affording the anode protection by the piping itself from external damage. This is a very cost effective cathodic protection installation when installed concurrently with the piping.
  • Ease of installation – when installed alongside the piping as the piping is being installed, the installation is simply a matter of laying the anode cable in the trench.

Our experts are happy to answer your questions about cathodic protection for underground piping.

Contact a Corrosion Expert

Video Demonstrates Cathodic Protection System Installation

Iron Gopher® Impressed Current Linear Anode System designed for horizontal directional drilling (HDD) is installed beneath an above ground storage tank (AST)

Chalfont, PA (May 27, 2015) – MATCOR, Inc. the trusted full-service provider of proprietary cathodic protection products, systems, and corrosion engineering solutions recently released a video showing the installation of the company’s Iron Gopher impressed current linear anode system at the site of an above ground storage tank in Texas.

Trenching to install cathodic protection systems may not be feasible for applications such as cross country pipelines, congested industrial environments and under above ground storage tanks. For these horizontal directional drilling applications, a linear anode with superior mechanical strength is required. The Iron Gopher with Kynex® technology is the only impressed current linear anode designed specifically for cathodic protection in horizontal directional drilling applications.

“As another example, Colonial Pipeline installed several thousand feet of our Iron Gopher® linear anode at an HDD project in NE Georgia,” said Ted Huck, VP of Sales for MATCOR. “With its unique design and greatly increased strength, Iron Gopher is superior to anything seen in the market for cathodic protection in HDD applications.”

Learn about MATCOR’s complete cathodic protection installation services.

About MATCOR