What Is Cathodic Protection and How Does It Work

cathodic protection hardware

Cathodic protection is a renowned and effective technique that is used to prevent the corrosion and deterioration of metals; it is used to protect industrial equipment and structures such as steel, water pipelines, storage tanks, oil platforms and ships. Corrosion occurs in structures that are located underground and are exposed to soil as well as in equipment that is located under water. If it is not addressed timeously, corrosion can have harmful effects on metal structures.

Corrosion is a gradual process that breaks down the properties of metals; this deterioration is a by-product of a chemical reaction that occurs between metals and their environment. Corrosion is a result of the redox reaction of iron and oxygen in an environment that has water or moist air.

How does cathodic protection work?

The harmful process of corrosion can be effectively prevented and managed through cathodic protection. The cathodic protection process involves the conversion of anodic sites on the metal surface into cathodic sites; this process is known as a cathodic electrochemical reaction. In the cathodic Protection process, direct current is used to counteract the corrosive chemical reaction (anodic reaction) that destroys metal surfaces. It must be noted, however, that while cathodic protection prevents metal deterioration and corrosion, it does not restore the damaged metal surface.

Cathodic protection can be used on various types of metal structures in various environments.  It is one of the few methods of corrosion control that can competently protect a submerged metal surface. In order for the cathodic protection process to be effective, you have to ensure that you design and acquire reliable cathodic protection current from your system.

Cathtect Engineering offers the following:

South Africa has been applying the cathodic protection technique on most railways and pipelines for the past 50 years. Cathtect Engineering prides itself on being an industry leader in cathodic protection and corrosion mitigation. We are a solutions-based company that offers high-quality products and professional services.

If you are looking for expert advice regarding cathodic protection, contact us today.



Saving Water Through Cathodic Protection


Burst Pipe - cathodic protection

Above: A site in Botswana, pointing out where a pipe burst due to the incorrect pipeline material use, causing an eruption of gushing water – Wasting 1000’s of litres of clean water. Cathtect Engineering was brought on board to fix this problem using Cathodic Protection.


South Africans were recently made aware of the water shortage problem that is affecting us, along with the drought that is going into the year 2016; we cannot just sit back and not take action. South Africans have been urged to save water and use water sparingly, to alleviate the causes of water shortage. Recently the government put “water shedding” into place, limiting the amount of water that South Africans can make use of. Many areas around South Africa have been affected by the lack of unending water supply, forcing consumers to save and store water in preparation of the next time they get affected by this water shedding series.

All over the world, resources are crucial to the success of countries, economies, and the ability to sustain life and this includes water. According to a source, by 2025 1.8 Billion people will experience absolute water scarcity and 2/3 of the World will be living under water-stressed conditions. Water shortages can cause a number of issues including economic and health issues.

Currently, leaking water distribution pipes in South Africa can cause a 50% water loss that does not even reach the consumer at all.  When pipes are unprotected, large amounts of money is spent on replacing these pipelines. As asset owners, managers and consumers all over the world, we need to do our part in saving and conserving water wherever we can.

This is where we come in, as a Cathodic Protection company, Cathtect Engineering does what it takes to fix and protect your pipelines and tanks. Cathodically protecting your water pipelines and tanks means corrosion can be mitigated as your pipelines keep the integrity of their design life, thus leaking water and wasting resources is kept to a minimum. 50% water loss due to poor pipeline integrity is NOT acceptable and Cathodic Protection is key to pipeline service life.

Cathtect has the years of experience, the equipment and the expertise to take care of your Cathodic Protection problem. We save your pipelines and tanks by utilising Cathodic Protection Principals so that corrosion does not take place, eventually causing leaks and damage.

At Cathtect, we provide full turnkey solutions, which means that we can analyse the Cathodic problem and provide the best solution from design to installation and monitoring. We are here to make a difference and provide you with the best solutions and service no matter where you are around the world!

Visit our website, Contact us and allow us to give you the best advice so that together we can make a difference!

Cathodic Protection Innovation at its Finest


In June 2015, one of Cathtect’s clients encountered a situation that they had no solution to. They did not know how to mitigate their corrosion problems; Cathtect took on this challenging project and came up with an innovative solution to our clients Cathodic Protection needs.

Theft of infrastructure kept recurring which interfered with corrosion protection on the pipeline, this lead to a decision by our client to find alternative methods to protect their pipelines from corrosion. Together with our client, we collaborated in order to find the best solution to the theft they were experiencing of AC power supply, cables and transformers.

Cathtect suggested to supply and install a solar powered rectifier to cathodically protect the water pipeline utilizing renewable energy through solar power supply systems. We were aware of the fact that theft is rife in the area, so we decided to secure the system to the existing concrete Durasafe which would minimize the chances of it getting stolen due to the robust construction and multiple safety measures applied. Since the system is solar powered it cuts down system footprint, the size and length of cable needed are minimized, thus, the chances of vandalism and theft of cables and equipment is reduced.

Our Solar Powered Rectifier is an innovative advancement in the application of Cathodic Protection. Cathtect designed, developed, manufactured and installed the Rectifier system to cathodically protect the pipeline using renewable energy and reduced footprint. Cathtect’s Solar Powered Rectifier is powered by a DC battery bank with controllable automatic output voltage. The battery bank is charged during daylight hours by suitably rated solar panels.

At Cathtect we do what it takes to find the best solution to our clients Cathodic Protection problems and we are proud to have found an innovative solution to an African problem. This system is sustainable, it does not make use of electricity and minimizes the overall power usage. The solution was not only the best solution to the problem but it is highly beneficial to our client now and in the long run. By installing this unit, it minimizes the capital costs as well as low maintenance and no ongoing power cost is incurred.

Cathtect’s Solar Powered Rectifier has a number of features that are beneficial to our clients; some include long design life, robust design and the choice of Remote Monitoring. We will design your system to suite your needs so that it can best meet your requirements.

Contact us and allow us to do what it takes to give you the very best in Cathodic Protection.


Cathtect’s Solid-State Decouplers

Solid-State Decouplers

The Cathtect Engineering (Pty) Ltd Solid-state Decoupling device is a solid state DC isolation / AC Grounding device.  It is specifically designed for protection applications generally found in buried pipeline and storage tank systems which are susceptible to corrosion.  The equipment is suitable to be employed in AC Mitigation applications, over voltage protection of Insulating Joints, DC isolation and AC Grounding of cathodically protected structures.

Cathtect’s Solid-State Decoupling devices are in standard packaging forms IP 66, IP 68 and explosive proof Exe enclosures. All components are fully accessible and are fully serviceable by suitably skilled artisans. Accessibility enables easy and speedy user programmable blocking/switching voltages.

The Solid-state Decoupler functions as a DC voltage level clamping device and at the same time mitigates AC voltage. This feature allows up to 15A AC induced current to pass through and prevents the flow of a DC current; while the DC voltage remains below the pre-determined design blocking threshold. When the DC voltage exceeds the aforementioned threshold the device instantaneously switches on and thereby limits the DC voltage of the device under protection. Immediately the voltage falls as the surge event passes and decays to below the threshold level, the SSD switches off and reverts to its blocking mode.

Applications of Cathtect’s Solid-State Decouplers

Our solid state De-Coupling devices are purpose designed to:

  • De-couple dissimilar metals that must, by regulation or galvanic corrosion, be AC bonded but isolated in the DC mode.
  • Isolate electrical DC equipment in Cathodic Protection systems.
  • AC coupling to earth where DC blocking/isolation is required.
  • Over voltage conditions emanating from Induced AC surges, lightning and switching transients and Rectifier failure.
  • Protection of Insulating joints on pipelines.
  • Mitigation of AC induced voltages.
  • De-Coupling in gradient control (earth / grounding) mats from pipelines and structures.

Protection of Insulating joints requires overvoltage protection due to the relatively small clearance between the flange faces, bolt to bolt hole and bolt head / nut to flange face. In order to protect the insulating materials used in the insulating flange kit, overvoltage protection devices are applied to ensure the voltage does not exceed pre-determined levels.

Cathtect has a wide range of Solid-State Decouplers that can be manufactured according to client specifications. We do what it takes to provide our clients with the best products and solutions, using our expertise and many years of experience.

Visit our website and get in touch with us, even if it’s just to say Hi!

Cathodic Protection with Cathtect Engineering – Our World Class Range of Rectifiers

Cathtect Engineering (Pty) Ltd offers the complete solution to your corrosion problem, by providing quality products and professional solutions throughout the Cathodic Protection spectrum. Cathtect is a technical market leader in its field and has intellectual capital that surpasses its competitors. We have successfully designed, supplied & installed equipment for institutions such as the Department of Defence (USA), Department of Water Affairs & Forestry, Armskor, Denel, Transnet, Transnet Pipelines, Eskom, Johannesburg Water, Fluor, Sasol Oil and Sasol Gas, amongst many other clients.

At Cathtect we design, manufacture, supply and install Cathodic Protection Rectifiers along with other Cathodic Protection products and equipment to solve Cathodic Protection problems. Our range of Cathodic Protection Rectifiers are suited to withstand different conditions and applications, each rectifier has standardised technical specifications which can be customised to suite your Cathodic Protection needs. We have dedicated engineers who constantly seek new and innovative ways to develop our products so that we can give you the very best in all that we do, utilising the latest technologies.

Cathtect’s range of Cathodic Protection Rectifiers include: Switch mode Rectifiers, Solar Powered Rectifiers, Automatic Controlled Rectifiers, Manually Controlled Rectifiers, Portable Rectifier Units and Oil Cooled Rectifiers. Each Rectifier is manufactured with individual care ensuring the highest quality in Cathodic Protection Rectifiers.

If you are looking for Innovative and technologically advanced solutions to your Cathodic Protection needs, contact Cathect Engineering so that we can do what it takes to supply you with World Class Cathodic Protection products & Solutions.

Cathtect Engineering’s warm welcome!

Welcome to our blogging journey, this is all very exciting for us! We decided to start this blog because we found a need in the market, the need for education around Corrosion. As a growing company in the Cathodic protection industry, it is important for us to educate and inform our clients and potential clients around this issue so that you can be aware of your corrosion problem. At Cathtect we find solutions through world-class Cathodic Protection equipment using our expertise that we have attained over 23 years of experience in installation worldwide to solve your corrosion problem.

Cathtect Engineering (PTY) Ltd is a Cathodic Protection Specialist company, Cathtect is based in South Africa, Roodepoort directed by David Raath, and driven by our CEO Aaron Raath, this is where we do what it takes! We are a dynamic company formed to provide need-based solutions and products to the Cathodic Protection industry both locally and internationally.

It is important for us as a business to keep growing, educating and building relationships with our clients and distributors so that we can be of value to you. We want to work together and grow to reach our goals and make a difference in the industry.

The focus of this blog is not only to educate and inform but we want to give you the chance to share your thoughts with us and give us some feedback. Be a part of the conversation and together we can build awareness around corrosion, prevent damage and spare the headaches that arise due to the lack of solutions and action to the corrosion problem.

Click here to view our Video

Follow us as we engage in a journey of providing solutions to Cathodic protection problems!