Category Archives: Storage Tanks

Tank Farm Design Recommendations for Corrosion Prevention

Tank Farm Design RecommendationsWhether designing a few above ground storage tanks or performing tank farm design for an entire facility, proper consideration should be given to the adverse impact of corrosion that can occur on the tank bottoms. When addressing the issue of tank bottom corrosion, consider the environment, the tank size and design, and the type of tank foundation to be employed. There are definite advantages in certain materials based on the size and requirements of an above ground storage tank (AST) foundation. By carefully assessing the tank farm surroundings and long-term requirements, costly and potentially dangerous corrosion related tank failures can be avoided. Whether you are relying on a reputable company in the industry or taking on your own front-end engineering and design, there are across-the-board tank farm design recommendations to consider when it comes to corrosion prevention:

In terms of corrosion prevention for under ground storage tank (AST) foundations, is cathodic protection (CP) effective?

For tanks erected on compacted soil or sand foundations, with or without a concrete ring wall, cathodic protection is considered a “good engineering practice” and has been proven as an effective means of addressing tank bottom corrosion concerns. When you compare various methods of corrosion prevention for above ground storage tank bottoms, CP is shown to prevail over asphalt or concrete unless your project involves smaller diameter tanks. The corrosion failure rate is greater for tanks built on asphalt or concrete compared to tanks where a concentric ring cathodic protection system is installed.

In terms of corrosion, when is asphalt or oil/sand acceptable for above ground storage tank (AST) foundations?

Asphalt foundations are not common in the United States, as the mechanical integrity of asphalt can be an issue depending on the AST environment. As well, the use of oil/sand layer designs has been phased out by most tank owners in the United States due to the adverse impact that these oil/sand layers have on cathodic protection systems. While historically prevalent in the Middle East and Asia, most larger national oil companies have abandoned this approach because it causes shielding of cathodic protection (CP) current, allowing corrosion to occur. Kuwait Oil, Aramco, and others now prefer clean sand combined with CP as the base material of choice. This is standard in the United States and has been for several decades.

What is a Concentric Ring Cathodic Protection System for above ground storage tanks (AST)?  

A. Designed for long-term storage, an AST cathodic protection ring system offers a factory-assembled design whereby the anode rings are ready to install with cable leads that extend past ring wall penetration. Concentric rings sizes are made to order, requiring no onsite welding, cutting, or splicing. The anode locations are marked, rings are laid out, and cabling is placed using a proven labeling system for future monitoring. A mixed metal oxide (MMO) anode is centered among a low-oxygen-generating coke backfill to eliminate depolarization.

Learn about MATCOR’s complete AST cathodic protection design services.

Are there some cases where concrete foundations are advantageous for tank farm corrosion prevention?

During installation of above-ground storage tanks, there are some advantages to concrete foundations for tanks when it comes to corrosion—the high pH of the concrete acts to passivate the steel, unless you have an above ground storage tank (AST) liner pad or something that is between the concrete and the tank bottom. If you can effectively seal the chime from the ingress of water and oxygen, the corrosion rates are generally quite small. Unfortunately concrete foundations for larger diameter tanks are not typically practical and can be quite expensive to properly install. Concrete foundations with appropriate AST liners are best for smaller diameter tanks.

In tank farm design for corrosion prevention, what are the best recommendations for above ground storage tank (AST) liners?

Plastic secondary containment liners are largely phased out in the United States and have been replaced by geotextile membranes that serve the same secondary containment purpose as plastic—they are conductive to allow cathodic protection (CP). The general standard in the United States is to have a CP system directly under the tank in order to minimize stray current or current losses due to earthing systems around the tank. Since the tank bottom is a large bare structure and the anodes are closely coupled to the tank bottom, there is usually very little current drain to other structures; the system if properly designed can accommodate modest current drain. While a plastic liner provides isolation from other nearby structures, when a problem arises with the CP system or if the CP system reaches the end of its projected service life, there is no way to install a new CP system without replacing the tank bottom.

Tank farm corrosion prevention is more manageable now than ever before. The MATCOR Concentric Ring Cathodic Protection System™ is just one of many excellent options for protecting your above ground storage tank (AST) from damaging corrosion.

For assistance with tank farm design, our Concentric Ring AST Cathodic Protection System™, project management or installation, please CONTACT US.

Learn more about Tank Cathodic Protection

Cathodic Protection Trends | Above Ground Storage Tanks

This presentation explores current cathodic protection trends for above ground storage tanks.

Statistics show owners of above ground tanks often experience external corrosion issues because of limited or poor installation methods. Typical above ground storage tank (AST) methods of the past involve a ring wall foundation that is generally formed with a sand or soil base, or even concrete for smaller tanks. It has previously been acceptable to use a galvanic ribbon anode system (generally magnesium), but this system often fails prematurely due to unstable sand-based foundations and poor connections. For this reason, the industry is moving away from the galvanic anode system and to newer concentric ring cathodic protection systems for above ground storage tanks.

Good Engineering Practices

While there are newer designs for AST cathodic protection systems, your first consideration should always be good engineering practices. The proper installation of a high-end AST cathodic protection system begins with known design specifications based on the tank size and diameter. This presentation compares traditional grid anode systems with newer linear anode concentric ring systems for the cathodic protection of above ground storage tank bottoms. In addition, congested terminal environments often lead to interference and less current at the tank bottom.

Grid Anode vs. Concentric Ring Cathodic Protection Systems

While the field-fabricated and field installed grid anode system has been in use for over 20 years, some faults have been discovered. Field installation presents welding challenges for the contractor because the system must first be secured, and it cannot be installed directly over sheet liner. The ribbon anode and titanium conductor bars have to be field cut to the appropriate lengths. At the conductor bar to anode ribbon intersections, a weld is applied. The field assembled grid system is subject to weld failures, the spot welds can be damaged easily during subsequent sand installation, and care must be taken to hold the system in place so that it does not short to the tank bottom. All of these installation challenges can adversely impact the system performance. Additionally, bare MMO in sand is an oxygen generator when used for cathodic protection. Oxygen is a depolarizer and in some instances this can lead to issues with maintaining polarization criteria.

Advantages of the Concentric Ring System

In comparison, newer concentric ring systems for above ground storage tanks include factory assembled anode rings that come equipped with the appropriate cable leads to extend past the ring wall penetration. No onsite field assembly is required. The system is pre-assembled in concentric ring sizes designed for your tank and requires no cutting, splicing, or welding, and the MMO wire is backfilled within a braided fabric sleeve with coke breeze. Anode locations are simply marked, each ring is laid out at the proper diameter, and cabling is extended toward the ring wall. The anode cables are labeled for ease of identification and to allow for monitoring of current to each anode ring. Unlike the grid system, the MMO anode is centered in a coke backfill – this coke environment inhibits the generation of oxygen eliminating the issues with depolarization.

The concentric ring tank cathodic protection system is designed for longevity. A typical under-tank ring system using MMO anodes exceeds a 30-year life, however can be designed to extend life beyond 100 years.

Additional Considerations for Tank CP

  • Some tank operators opt for a “replaceable” anode system, however time and manpower are required to extract and replace the anodes and backfill and the design life is only 30 years.
  • Volatile corrosion inhibitors (VCI) are often used in conjunction with cathodic protection systems where CP cannot be installed or may be ineffective, such as ring wall crevices, poor bottom-to-sand contact, and more. It can be pumped under tanks via shielding high-density polyethylene (HDPE) containment liners.

Today, tank owners have more effective choices than traditional grid anode systems for tank cathodic protection. The MATCOR Tank Ring Anode™ System is trending as a high-end solution for above ground storage (AST) tanks.

For assistance with tank cathodic protection system design, MATCOR’s Tank Ring Anode System, project management or installation, please CONTACT US.

Learn more about AST Cathodic Protection

Tank CP Installation – A Drone’s View!

Easy to Install Tank CP System – No Cutting, No Splicing No Welding

Tank CP InstallationWe’re excited to share this aerial drone view of a recent tank CP installation starring MATCOR’s exclusive Tank Ring Anode™ System. Superior to grid anode systems for tank bottom cathodic protection, the Tank Ring Anode System is factory assembled in concentric rings sized for your tank and shipped ready for quick installation.

  • Impressed current anode
  • New and retrofit tanks
  • Ready to install
  • No field assembly required
  • Superior current distribution
  • USA manufactured

Learn about MATCOR’s complete cathodic protection installation services.

Concentric ring anode configuration ideal for tank bottom cathodic protection

Learn more about this newer method of cathodic protection for tanks and its benefits over the more traditional grid anode system—read the full article at HERE.

MATCOR tank app

For assistance with impressed current anode system design for tank bottoms, project management, installation or field service, 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


External Tank Bottom Cathodic Protection

External corrosion of above ground storage tank (AST) bottoms is a significant problem for tank owners. Corrosion professionals tasked with protecting these structures should consider multiple factors. One thing is clear: proper installation of an impressed current tank bottom cathodic protection system plays an important role in reducing corrosion and extending the service life of the tank bottom.

Concentric ring anode configuration ideal for tank bottom cathodic protection

Tank Bottom Cathodic Protection Article from NACE Materials Performance

Learn more about this newer method of AST cathodic protection and its benefits over the more traditional grid system.

For additional information about tank bottom cathodic protection, please read our article in the special supplement “Corrosion Control for Aboveground and Belowground Storage Tanks” in the May issue of NACE International’s Materials Performance.


Contact MATCOR about your AST cathodic protection requirements or learn more about our Tank Ring Anode™ System.

Learn more about Tank Cathodic Protection

Cathodic Protection for Missile Defense Shield in Romania

As you watch the evening news or pick up your daily paper you will very likely read about the new Missile Defense Shield in Romania that came on line this week. The Russian response has been loud and indignant. This story will be all over the evening news, cable channels and newspapers.

But did you know that the Deveselu facility in Romania has a MATCOR Cathodic Protection system protecting the buried piping and process tanks? MATCOR VP of engineering Glenn Shreffler made three trips to the site during its construction. So when you watch the evening news and they discuss the “controversial” missile defense base in Romania, we are proud that MATCOR anode systems are hard at work protecting the assets that protect our NATO allies.

Contact MATCOR about your tank and piping cathodic corrosion prevention requirements or learn more about our wide range of cathodic protection products.

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.


Cathodic Protection Systems Vital in Above Ground Storage Tanks

In January 2014, above ground storage tanks (ASTs) containing the chemical 4-methylcyclohexanemethanol (MCHM) was released into Elk River in West Virginia. The leaks, which cursory reports believe to be the likely the result of corrosion, could have been avoided by implementing proper cathodic protection systems.

The facility, operated by Freedom Industries, containing the chemical was located in Charleston, West Virginia. Recently, federal investigators discovered that the spill might have originated from more than one tank and could account for up to 10,000 gallons of MCHM.

This catastrophe, which left the 300,000 residents across nine West Virginia counties without potable water, could have been avoided by taking proper precautions.

The spill is currently being attributed to corrosion in the above ground storage tanks that held the MCHM. Corrosion is a serious and persistent concern for ASTs, which must withstand the elements.

“Above ground storage tanks pose a specific set of problems when it comes to corrosion prevention. The evidence collected by several federal agencies suggests that this hazardous leak was the result of a tank bottom leak,” said Ted Huck, vice president, international sales and practice lead – plants and facilities at MATCOR. “The leak was caused by the corrosion of the tank bottom due to contact of the external tank plate with the soil.

“The resulting soil-side hole could have been prevented by MATCOR’s patented cathodic protection systems. While cathodic protection systems are commonly used in oil and gas storage tanks, they are not mandated and there are tanks across the country that do not have cathodic protection systems installed to protect tank bottoms from leaking.”

Cathodic protection systems are critical for preventing corrosion in ASTs.

Cathodic Protection Systems

The soil-side hole that resulted in the released chemical is a common problem among ASTs. MATOR has developed a reliable protection system for ASTs which uses our unique SPL-Anode system and patented Kynex® technology.

When building and maintaining above ground storage tanks consider the importance of cathodic protection systems. Learn more about MATCOR’s unique cathodic protection system for ASTs or contact us today.

CSB report reveals holes in more tanks at Freedom site,” Charleston Daily Mail, June 16, 2014.

Learn more about AST Cathodic Protection

Extensive Corrosion Found – Port Arthur Refinery

Extensive corrosion, that may require up to five months to repair, has been found inside a new 325,000 barrel per day (bpd) crude distillation unit at a 600,000 bpd Port Arthur, Texas, refinery, according to sources familiar with refinery operations.

The root cause of the corrosion, found in vessels and piping on the crude distillation unit (CDU), has not been determined, the sources said.

Damage from a fire on the CDU during an attempted June 9 restart was seen as negligible, the sources said.

The refinery owner won’t know the full scale of repair work needed until it determines the cause of the corrosion, the sources said.

A representative was not immediately available to discuss refinery operations. On Friday, the owner said there was no timeline for bringing the crude unit back into production.

The unit began refining crude oil in April and was officially commissioned at a May 31 ceremony

This particular refinery’s Port Arthur CDU was built to run heavy, sour crude oil grades that have a high risk of corroding refinery units due to high sulfur content.

“There’s extensive corrosion in the crude unit itself,” one of the sources said. “All of it. Piping, vessels, all of it. It could take up to five months to fix. It will be several months.”

The CDU, which does the initial refining of crude oil coming into the refinery and provides the feedstock for all other refining units, is the centerpiece of a $10-billion, 5-year project to expand the refinery to be the nation’s largest.

At the time, the CDU was shut down it was three weeks away from reaching full production, a refinery owner executive had said.

U.S. Navy Settles Underground Storage Tank Violations at Hampton Roads Facility

The U.S. Navy has agreed to pay a $5,855 penalty to settle alleged underground storage tank (UST) violations at its Building NH94, located at 7918 Blandy St., Norfolk, Va., the U.S. Environmental Protection Agency announced today.

There are three 25,000-gallon underground storage tanks at this facility containing diesel fuel. Each UST is required to be tested every three years to make sure the tank is not corroded and that the corrosion protection system is operating properly. During a March 2011 inspection, the inspectors found that these tanks had not been tested since 2004. 

The $5,855 settlement penalty reflects cooperation of the U.S. Navy with EPA in the investigation and resolution of this matter. The Navy has certified its compliance with applicable UST requirements and the tanks were tested for corrosion on April 4, 2011. 

Underground storage tanks must be tested to prevent leaks, because the greatest potential threat from a leaking UST is contamination of groundwater, the source of drinking water for nearly half of all Americans. These leaks can threaten public safety and health as well as the environment because UST systems contain hazardous and toxic chemicals. Cleaning up petroleum leaks is difficult and usually expensive. Federal regulations ensure that USTs are structurally sound because it is easier and less costly to prevent leaks before they happen.