Category Archives: Cathodic Protection

At What Distance Does Cathodic Protection Continue to be Effective?

This article explores the answer to a question posed by a student about the length of pipeline protected by a cathodic protection system.


What length of pipeline is protected by a cathodic protection system?

We recently received a question from our website from someone who self-identified as a Student. We love when people ask technical questions and are pleased that students visit the MATCOR website–we have always strived to have a content-rich website to help share CP knowledge. The question is as follows:

“For installed impressed current CP systems with 15 anodes, what would be the approximate radius/length of a 200-mile petroleum metal pipe that would be protected?”

So before diving into the answer, let’s frame this question with an assumption, identify some unknowns and provide a definition.

Assumption

The 15 anodes are part of a single anode bed. The anodes are electrically remote from the pipeline and connect to an appropriately-sized DC power supply (transformer/rectifier, solar power/battery unit, thermoelectric generator, etc.)

Unknown #1: Pipeline Details

Before doing any detailed engineering, there are a few details that must be specified:

  • Pipeline diameter and material of construction
  • Coating type and condition
    • The layout of the pipeline (location of pumping stations, valve stations, and metering stations)

Unknown #2: Soil Conditions

Understanding soil resistivity in terms of location, frequency, and spacing, is critical when designing cathodic protection systems for long-length pipelines.

Definition of Attenuation

a lessening in amount, force, magnitude, or value according to Merriam-Webster

When discussing at what distance cathodic protection continues to be effective along a pipeline, you must consider the attenuation of the CP current. At some point, the current diminishes along the length of the pipeline, becomes insufficient, and can no longer protect the pipeline.

The Answer: Impressed Current CP Systems are Complicated

We can effectively use attenuation calculations for signals generated on a uniform conductor and transmitted through a uniform environment.

In this case, the pipeline is not a uniform conductor; unless it is bare, it is anything but uniform. The coating has less than perfect effectiveness and an unknown number of defects distributed in an unknown manner. The environment is equally non-uniform; soil resistivities change based on location and weather changes. The more non-uniformity, the more inaccurate the results will be for any attenuation calculations.

It is virtually impossible to model mathematically for older pipelines with insufficient coatings. The only effective strategy is to collect data by installing a temporary current source to measure the effective current throw in each direction in multiple locations along the pipeline.

For new pipelines with very good coatings, it is possible to perform some attenuation calculations and empirically determine a reasonable separation distance between anode stations.

The math starts with determining something called the propagation or attenuation constant. To calculate this, take the square root of the resistance per unit length of the structure divided by the leakage conductance per unit length.

In Simple Words…

How hard is it for the current to travel along the pipeline versus how easy it is for the current to jump onto the pipeline?

The smaller this number, the further current will spread. Key factors affecting the attenuation constant include earth resistivity (higher resistivity soils mean further current spread) and coating quality (better coating means further current spread). Armed with this, there are six simultaneous equations that we can use, and that include hyperbolic sine and cosine functions.

Larger, new construction pipeline projects require you to consult with a professional engineer. A brief newsletter article will not adequately cover the mathematical gymnastics involved. We did say that the math is complex.

Well-coated, newer pipelines in moderate to high-resistivity soils can typically be protected for 20+ miles in each direction from an anode bed. Poorly-coated or bare pipelines in low-resistivity soils may require anodes every quarter mile or less.


Need more information? Please contact us at the link below.

Is My Tank CP System Working Correctly?


Ted Huck, Director of Manufacturing and QA/QC at MATCOR, recently published an article in the summer edition of Tanks and Terminals Magazine titled “Understanding Cathodic Protection Systems.” He explains how to assess the performance of cathodic protection systems for above-ground storage tank bottoms (Tank CP Systems).

When asked to summarize these performance assessments, Mr. Huck commented, “Tanks are pretty easy to test, except for those rare occasions when they are not. At that point seek professional help.”

Read the full article.


Need information or a quote for MATCOR tank CP systems? Please contact us at the link below.

Three Ton Sled Anode Assemblies Head to Beaumont, Texas

MATCOR shipped four of the heaviest customer sled anodes we have ever fabricated this month – over three tons each. Headed to Beaumont, TX, the anodes are part of a Gulf Coast refinery expansion project. The anodes will protect a variety of marine piling structures as part of a light crude processing expansion at the refinery.

Sled Anode assembly – pouring the concrete bases.

Each anode is rated for 75 amps and weighs approximately 6300 pounds. Each anode assembly consists of a pair of two-inch diameter Mixed Metal Oxide coated titanium tubular anodes, five-foot-long. The anodes utilize MATCOR’s proprietary tubular anode connection technology for larger diameter anode tubes. Each sled anode has two concrete bases resting on a common wood base fabricated with stout 6” x 6” pressure-treated wooden beams. The concrete ends include lifting lugs to support installation by crane either from land or on a work boat. The function of the treated wood beams is to sink into the sea floor.

Completed Sled Anode assembly – waiting on the concrete to cure.

The anode lead cables are dual insulated HMWPE/ Kynar 1/0 cables housed in a proprietary HDPE jacket and held in place along the sea floor using concrete weights.

Sled Anodes are an exceptionally cost-effective means of protecting large near-shore structures such as dolphins, jetties, pilings, and sheet pile walls. They are easy to install and even easy to remove in advance of dredging operations.

More Information About MATCOR’s Sled Anode Products

Marine Anode Sled Product Page

Houston Sled Anode Installation

[YouTube Video] MATCOR Sea-Bottom™ Marine Anode Sled

[Materials Performance Case Study] Impressed Current Anode Systems for Jetty Piling


Need information or a quote for MATCOR custom sled anodes? Please contact us at the link below.

Coke Column Guidelines for Deep Anode Systems

OH NO, My Anode Bed is Not Performing!

This article explores a deep anode system gone wrong and guidelines for properly sizing the system coke column.


Earlier this year, we received a call from a pipeline customer with whom we have a solid relationship.

Historically, they used graphite anodes for their deep anode installations. But over the past few years, they began trying the MATCOR Durammo® Deep anode System with success.

When one of their new Durammo anode installations started having strange operating data, it was time to get MATCOR on the phone pronto and figure things out.

MATCOR reviewed the RMU operating data on the wayward installation and found that the data was indeed strange.

The DC output oscillated from periods of robust DC current output to periods of no discernible DC output. We also looked at the deep anode system design and noted the rather short coke column height. The height was only 100 ft of active anode in an 8-inch column. We sent a technician to the site to investigate.

First, we checked the installation and operation of the remote monitoring unit (RMU). Was a poor RMU connection causing intermittent good/bad data? This was not the case.

Next, we checked the continuity of the two anode lead cables. The Durammo® system has a top lead cable and a bottom lead cable. These two cables should be electrically continuous. In this installation, they checked out properly.

Finally, we checked the vent pipe for obvious issues.

Having confirmed that the spurious data was not the result of a poor RMU connection and that the anode system cabling appeared to be intact, we began to suspect that the problem was in the coke column and its immediate environment.

The Culprit? A Small Coke Column.

When we investigated further, we determined that the on-again, off-again readings could be the result of excessive gas generation into a rather small coke column. Both phenomena are heavily impacted by the anode system’s coke column to earth current density.

When the anode system generates more gas than can be exhausted through the vent pipe and diffused through the surrounding earth, gas molecules begin to accumulate between the column particles and at the anode to coke and coke column to earth interfaces. Gas is not electrically conductive, and with enough trapped gas in the column, the system resistance can quickly rise to a point that the anode system cannot overcome this resistance, and the current output drops quickly.

A short-term solution is to turn off the anode system for a period, allowing the gas to disperse inside the coke column and the system should return to normal operation. At least until the gas molecules build up again to block the anode system.

Coke Column to Earth Interface Current Density: The Magic Number

The magic number often cited for anode coke column to earth interface current density is 150mA/ft2. Anything above this number might cause problems. Below this number, history shows that the impact of gas blockage and drying out are generally minimal.

In our example, a 100 ft coke column with an 8-inch diameter hole means that any current output above 31 amps would be pushing that 150mA/f2 threshold.

The 150mA/ft2 current density assumes a high-quality, properly installed coke. This forms a well-compacted column that promotes electronic conduction and limits electrolytic conduction. A well-formed coke column is critical for anode systems using mixed metal oxide anodes, since MMO anodes have an inherently smaller surface area available to be in contact with the column.

It is unclear why the cp system designer recommended a short anode active length for this anode system – other than perhaps the cost saving of using less coke backfill.

While a shorter column does have a positive cost impact, the performance can become an issue, as was the case with this installation. Ultimately, this customer is planning a new Durammo® anode installation for this location with a significantly longer active area.


Need information or a quote for MATCOR deep anode systems? Please contact us at the link below.

MATCOR’s Ted Huck to Keynote at CORCON 2021

MATCOR’s Ted Huck, cathodic protection and AC mitigation expert, is pleased to be a keynote speaker at this year’s CORCON.

Ted Huck, MATCOR, Inc.

CORCON is Asia’s largest corrosion conference, hosted annually by the NACE International Gateway India Section (NIGIS).

The only larger corrosion conference is the NACE CORROSION Conference held annually in the Spring by NACE – we hope to see all of you in San Antonio Texas in 2022 where next year’s CORROSION Conference is scheduled.


Did you know? Our very own Ted Huck is “Youtube Famous” for his Cathodic Protection 101 video, with nearly a quarter-million views!


This year, the CORCON conference is virtual; however, the need for an opportunity to share information and experiences still exists. Even in the midst of a pandemic, show organizers are optimistic that they can resume a live conference in 2022.

MATCOR has over a decade-long history of involvement in the cathodic protection market in India. The company has participated in numerous CORCON conferences as speakers, session chairs, and as an exhibitor.

Corrosion Professionals in India

MATCOR has a small office and staff in Ahmedabad, India and we believe in the great work performed by the many corrosion professionals in India.

This year, we were pleasantly surprised when conference organizers reached out to Ted Huck, a frequent visitor and speaker at the NIGIS CORCON conference, to ask that he be a keynote speaker.

Corcon 2021 Keynote

On November 18, Mr. Huck delivered the presentation “AC Mitigation Criterion and the impact on Cathodic Protection Operations.”

The conference is scheduled for November 18-20, 2021.  For more information visit www.corcon.org.

In addition to speaking at the CORCON conference, you can also find MATCOR at the National Institute for Storage Tank Management conference in the Woodlands December 1st and 2nd.  Mr. Huck will be speaking in person at that conference on Tank Bottom Cathodic Protection Systems – Replacement Options.

Cathodic Protection Construction and Inflation

How Today’s Supply Chain Issues Affect Our Industry

For over a decade both the consumer and construction worlds have enjoyed very stable pricing with modest annual increases. 2021 is a very different picture. Suppliers are dealing with supply chain issues and price spikes. These increases far exceed the 2-3% we typically see for cathodic protection construction projects.

Cathodic Protection Construction

In today’s environment, manufacturers and service providers deal with this uncertainty by providing quotes with very limited duration. In some cases quotes are only valid for a few days. This is a far cry from the 30- to 90-day validity once common in the industry.

The challenge for everyone in the industry is the lag time between the budgeting phase of a project and the purchase of materials. For major projects, the planning, permitting and pre-construction phases of a project can take years.

It is important to note that the inflation figures we see quoted in the news are typically “consumer price index.” These inflation figures run about half of the less reported “producer price index,” which more accurately captures manufacturers’ material costs.

When you hear that the core inflation rate is 4 or 5%, you can reasonably expect that material costs are rising at 8-10%.

What can companies performing cathodic protection construction do to manage project budgets in an inflationary environment?

  • Take action quickly. Time is money. The longer you wait to purchase materials and services, the more you can expect to pay for them. Once you have approval for a cathodic protection project, order the key materials quickly.
  • Share the inflation risks fairly with your suppliers and contractors. Holding a contractor to yesterday’s prices is unrealistic and unsustainable. That contractor will be looking for ways to cut costs. And they may accomplish it by cutting quality, reducing the scope, substituting cheaper materials, or demanding change orders at every opportunity. This type of relationship does not benefit any of the parties.
  • Consider ordering materials separately from construction. This applies especially to materials you can pre-stage, have long storage life, or repurpose easily for other projects.
  • Be realistic when providing project schedules. Haven’t nailed down all the landowner or permit issues? Then don’t tell your suppliers and contractors that you expect the project to kick off next month.

What is MATCOR doing to address issues related to cathodic protection construction projects?

As a supplier of cathodic protection materials and construction services, MATCOR takes a team approach. We are eager to engage with customers and work together to minimize impacts from cathodic protection supply chain disruptions and price increases.

Stretch Your Cathodic Protection Budget

Now is a great time to think about stretching your 2021 budget and getting a jump start on 2022.

Days are growing shorter and long summer days are turning to dark winter days. This makes it difficult to spend the last of your CP budget dollars on completed construction projects this year.

Equipment and crews are generally already booked. However, MATCOR and our sister company JA Electronics can still help you spend your 2021 budget dollars productively.

We still have manufacturing capacity for this year. Purchasing cathodic protection anodes, rectifiers and other CP components now can help use up those remaining funds while also giving you a head start on 2022 projects.

Get Your Act Together

The first quarter is often a slower quarter in the construction business since companies are still planning their 2022 CP spend.

But what if you had your act together and were ready to start cathodic protection construction projects earlier in the year?

Well, we at MATCOR are eager to talk to you about special off-season pricing that we can offer for Q1 projects. Are you in a position to buy materials in Q4 and install them in Q1 of 2022? We can load share our construction capacity and provide off-peak pricing, making it very attractive indeed to have your act together.


Have questions or need a quote cathodic protection materials or construction services? Contact us at the link below. For immediate assistance, please call +1-215-348-2974.

Contact a Corrosion Expert

MATCOR Featured in Tanks and Terminals

In the June 2021 issue of Tanks and Terminals, a quarterly supplement to Hydrocarbon Engineering, MATCOR’s Ted Huck discusses cathodic protection of terminal marine structures including docks, jetties, piers, seawalls and sheet pilings.

Protecting Marine Structures From Corrosion

The article includes a case story discussion from a Texas gulf coast facility using impressed current cathodic protection for a combi-wall structure (consisting of pipe piles and sheet walls.).

MATCOR provides industry leading cathodic protection and AC mitigation solutions to tank and terminal operators around the globe.

MATCOR’s New Offices Rock Customer Satisfaction

In 2019, MATCOR opened new offices in Casper WY, and Midland, TX to better support those regions.

Two years and one pandemic later, we have seen great success from both regions as we’ve increased our service capacity, deployed construction crews and technicians and staffed each office with experienced cathodic protection professionals.

We recently highlighted a success story from our Casper Wyoming office detailing a successful AC Mitigation installation project.

This month we wanted to highlight a similar customer success story from our Horizontal Directional Drilling crew for two recent tank anode systems installed for a Texas based Midstream company with operations in the Permian.

Upon completion of the project, we received a compliment from the client’s Corrosion Supervisor, who reached out to MATCOR’s Permian based project manager, Mario Mahabir saying:

“Gentlemen, just wanted to extend our gratitude for the performance and professionalism we experienced from your team on the recent project at our facility.”

Well MATCOR appreciates the opportunity to work on this project!

For the this project, MATCOR designed, installed and commissioned dedicated under tank cathodic protection systems on two above ground storage tanks.

Installation was performed using our horizontal directional drilling rig and MATCOR’s proprietary mixed metal oxide anodes to install anodes and reference electrode pull tubes under two existing tanks.

Give the MATCOR Permian and Rockies teams a look—we think you will like what you see.


Have questions or need a quote for AC interference mitigation materials or services? Contact us at the link below. For immediate assistance, please call +1-215-348-2974.

Contact a Corrosion Expert

Navigating Cathodic Protection Supply Chain Issues

June 2022 Update

MATCOR has historically stocked and specified dual insulated HMWPE/Kynar™ for all of our chemically aggressive cable applications. Many other suppliers in our industry utilize HMWPE/Halar™ for their chemically aggressive cable applications. The two are generally seen as being equivalent materials for cathodic protection purposes.

Due to recent supply chain disruption, MATCOR has had to provide HMWPE/Halar™ in place of HMWPE/Kynar™. This is due to the availability of materials.

Unless explicitly instructed otherwise, MATCOR reserves the right to substitute these two cable installations interchangeably based on material availability.

Should you have any questions, please contact your MATCOR sales representative.

May 2021 Cathodic Protection Supply Chain Update

Historically, MATCOR has enjoyed an exceptional on-time delivery record. Over the past decade our lead times for anodes have gone down. 1-2 weeks for rush orders is quite achievable. 3-4 week deliveries are the norm for MATCOR manufactured cathodic protection products. Through 2020, we were able to navigate cathodic protection supply chain issues and avoid delays due to material availability.

However, if you are reading the news, you cannot help but see stories the stories:

The general state of the global economy is one of delay and disruption accompanied by price increases and surcharges.

In our cathodic protection manufacturing business, we have not been immune to these pressures. Supply is tighter and orders delayed for key items we use on a regular basis. This includes lumber for anode reels to Iridium for our mixed metal oxide anode coatings. Cathodic protection cable availability, especially for Kynar dual insulated cable, has gone from 4-6 weeks to 15+ weeks.

Shipping Issues

The cost and reliability of shipping channels is another challenge facing manufacturers. Both ocean freight and motor freight are struggling with shortages of containers, truck drivers, port congestion and rising fuel costs. Getting materials to our manufacturing facility and shipping them out is more difficult and less reliable than ever before.

At MATCOR, we have a great logistics team and a very flexible manufacturing team. Our on-time delivery record has suffered, but we are doing everything we can to minimize the impact on customers. We communicate early and often with those affected to advise them of any supply delays.

We encourage our customers to give themselves additional lead time by purchasing materials a little earlier than normal. This will assure that they have them on site well in advance of their planned installation. Engage early with MATCOR and your other suppliers to coordinate delivery timeframes. This is a good idea for both planned projects and critical timeline projects as we navigate these challenging times.

More about How Today’s Supply Chain Issues Affect Our Industry.


Don’t allow cathodic protection supply chain issues to affect your project. Plan ahead by contacting us at the link below. For immediate assistance, please call +1-215-348-2974.

Contact a Corrosion Expert

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