Protecting metal from corrosion by applying an external direct electric current, which radically changes the electrode potential of the material and changes the rate of its corrosion, is called electrochemical protection. It reliably protects surfaces from corrosion, preventing the destruction of underground tanks, pipelines, ship bottoms, gas tanks, hydraulic structures, gas pipelines, etc. This method is used in cases where the corrosion potential is in a zone of intense decay or during passivation, that is, when active destruction of metal structures occurs.

Operating principle of electrochemical protection

TO metal structure a source of direct electric current is connected externally. On the surface of the product electric current forms cathodic polarization of the electrodes, as a result of which an exchange occurs and the anodic areas are transformed into cathodic ones. As a result, under the influence of a corrosive environment, the anode is destroyed, and not the source material. This kind of protection is divided into cathodic and anodic, it depends on which direction (negative or positive) the potential of the metal shifts.

Cathodic corrosion protection

Example: (+0.8)Au/Fe(-0.44)

To increase the stability of metal parts in contact with any aggressive environment or during operation with exposure to sea ​​water or soil, cathodic corrosion protection is applied. In this case, cathodic polarization of the stored metal is achieved by forming a microgalvanic couple with another metal (aluminum, zinc, magnesium), reducing the speed of the cathodic process (deaeration of the electrolyte) or applying an electric current from external source.

This technique is usually used to preserve ferrous metals, because most of the objects located in soil and water are made from them - for example, piers, pile structures, pipelines. Wide Application This method has also been found in mechanical engineering, in the prevention of corrosion processes of new and in-use vehicles, when processing the car body, side member cavities, chassis components, etc. It should be noted that this same method effectively protects the underbody of the car, which is most often exposed to exposure to aggressive environments.

Cathodic protection, with many advantages, still has disadvantages. One of them is an excess of protection; this phenomenon is observed when the potential of the stored product is strongly shifted in the negative direction. The result is metal fragility, corrosion cracking of the material and destruction of all protective coatings. Its type is tread protection. When using it, a metal with a negative potential (protector) is attached to the stored product, which is subsequently destroyed, preserving the object.

Anodic protection

Example: (-0.77)Cd/Fe(-0.44)

Anodic protection against metal corrosion is used for products made from high-alloy ferrous alloys, carbon and acid-resistant steel, located in corrosive environments with good electrical conductivity. With this method, the metal potential shifts to positive side until it reaches a stable (passive) state.

The anode electrochemical installation includes: a current source, a cathode, a reference electrode and a stored object.

In order for protection to be as effective as possible for any specific item, certain rules must be followed:

minimize the number of cracks, crevices and air pockets;

the quality of welds and connections of metal structures must be maximum;

the cathode and reference electrode must be placed in the solution and remain there permanently

There are various methods processing of metal pipes, but the most effective of them is cathodic protection of pipelines against corrosion. It is necessary to prevent their premature depressurization, which will lead to the formation of cracks, cavities and ruptures.

Metal corrosion is a natural process in which the atoms of a metal change. As a result, their electrons pass to oxidizing agents, which leads to destruction of the structure of the material.

For underground pipelines, an additional factor of corrosion influence is the composition of the soil. It contains areas of different electrode potential, which causes the formation of corrosive galvanic cells.

There are several types of corrosion, including:

• Solid. It is distinguished by a large continuous area of ​​distribution. IN in rare cases causes damage to the pipeline, since it often does not penetrate deep into the metal structure;


• Local corrosion – becomes the most common cause ruptures, since it does not cover a large area, but penetrates deeply. It is divided into pitting, filamentous, through, subsurface, spotty, knife, intergranular, corrosion brittleness and cracking.

Methods for protecting underground pipelines

Protection against metal corrosion can be either active or passive. Passive methods involve creating conditions for the pipeline in which it will not be affected by the surrounding soil. To do this, special protective compounds are applied to it, which become a barrier. The most commonly used coatings are bitumen, epoxy resins, polymer tapes or coal tar pitch.

For the active method, cathodic protection of pipelines against corrosion is most often used. It is based on the creation of polarization, which makes it possible to reduce the rate of metal dissolution. This effect is realized by shifting the corrosion potential to a more negative area. To do this, an electric current is passed between the metal surface and the soil, which significantly reduces the corrosion rate.

Methods for implementing cathodic protection:

• Using external current sources that are connected to the protected pipe and to anode grounding;


• Using the galvanic method (magnesium sacrificial anode protectors).

Cathodic protection of pipelines against corrosion using external sources is more complex. Since it requires the use of special designs that provide direct current. The galvanic method, in turn, is implemented using protectors that make it possible to provide effective protection only in soils with low electrical resistance.

Can be used to protect the pipeline and the anodic method. It is used in conditions of contact with an aggressive chemical environment. The anodic method is based on converting the active state of the metal into a passive one and maintaining it due to the influence of an external anode.

Despite certain difficulties in implementation, this method is actively used where cathodic protection of pipelines against corrosion cannot be implemented.

Examples of cathodic protection of pipelines against corrosion at the exhibition

Experience of use and new developments in this area are highlighted at the annual industry exhibition "Neftegaz", which takes place at the Expocentre Fairgrounds.

The exhibition is a major industry event and an excellent platform for introducing specialists to new developments, as well as launching new projects. The Neftegaz exhibition will be held at the Expocentre Fairgrounds in Moscow on Krasnaya Presnya.

Read our other articles.

Pipelines are by far the most common means of transporting energy carriers. Their obvious drawback is their susceptibility to rust. This is achieved by cathodic protection. main pipelines from corrosion. What is its principle of operation?

Causes of corrosion

Networks of pipelines for life support systems are distributed throughout Russia. With their help, gas, water, petroleum products and oil are efficiently transported. Not long ago, a pipeline was laid to transport ammonia. Most types of pipelines are made of metal, and their main enemy is corrosion, of which there are many types.

The reasons for the formation of rust on metal surfaces are based on the properties environment, both external and internal corrosion of pipelines. Risk of corrosion for internal surfaces based on:

1. Interaction with water.
2. The presence of alkalis, salts or acids in the water.

Such circumstances may arise on main water supply systems, hot water supply (DHW), steam and heating systems. No less important factor is the method of laying the pipeline: above-ground or underground. The first one is easier to maintain and eliminate the causes of rust formation compared to the second one.

With the pipe-to-pipe installation method, the risk of corrosion is at least low level. When directly installing the pipeline on outdoors rust may form from interaction with the atmosphere, which also leads to a change in design.

Pipelines located underground, including steam and hot water most vulnerable to corrosion. The question arises about the susceptibility to corrosion of pipes located at the bottom of water sources, but only a small part of the pipelines are located in these places.

According to their purpose, pipelines with a risk of corrosion are divided into:

• main lines;
• fishing;
• for heating and life support systems;
• For waste water from industrial enterprises.

Susceptibility to corrosion of main pipeline networks

Corrosion of pipelines of this type is most well studied, and their protection from exposure external factors defined by standard requirements. IN regulatory documents methods of protection are considered, and not the reasons for the formation of rust.

It is equally important to take into account that in this case only external corrosion is considered, to which the outer section of the pipeline is susceptible, since inert gases pass inside the pipeline. In this case, contact of the metal with the atmosphere is not so dangerous.

For protection against corrosion according to GOST, several sections of the pipeline are considered: increased and high danger, as well as corrosive.

Impact of negative factors from the atmosphere for areas increased danger or types of corrosion:

1. From DC sources the occurrence stray currents.
2. Exposure to microorganisms.
3. The created stress provokes cracking of the metal.
4. Waste storage.
5. Salty soils.
6. The temperature of the transported substance is above 300 °C.
7. Carbon dioxide corrosion of an oil pipeline.

An installer for protecting underground pipelines from corrosion must know the design of the pipeline and the requirements of SNiP.

Electrochemical corrosion from soil

Due to the difference in voltages formed in individual sections of pipelines, an electron flow occurs. The process of rust formation occurs according to the electrochemical principle. Based on this effect, part of the metal in the anodic zones cracks and flows into the base of the soil. After interaction with the electrolyte, corrosion forms.

One of the significant criteria for ensuring protection against negative manifestations is the length of the line. On the way there are soils with different composition and characteristics. All this contributes to the emergence of a voltage difference between parts of the laid pipelines. The mains have good conductivity, so the formation of galvanic couples with a fairly large extent occurs.

An increase in the rate of pipeline corrosion provokes high density electron flow. The depth of the lines is no less important, since it retains a significant percentage of humidity and the temperature is not allowed to fall below the “0” mark. Mill scale also remains on the surface of the pipes after processing, and this affects the appearance of rust.

By conducting research work A direct relationship has been established between the depth and area of ​​rust formed on the metal. This is based on the fact that metal with a larger surface area is most vulnerable to external negative manifestations. Special cases include the occurrence of significantly smaller amounts of destruction on steel structures under the influence of the electrochemical process.

The aggressiveness of soils to metal is, first of all, determined by their own structural component, humidity, resistance, alkali saturation, air permeability and other factors. The installer for the protection of underground pipelines from corrosion must be familiar with the pipeline construction project.

Corrosion under the influence of stray currents

Rust can arise from an alternating and constant flow of electrons:

• Rust formation under the influence of constant current. Stray currents are currents found in the soil and in structural elements located underground. Their origin is anthropogenic. They arise as a result of exploitation technical devices direct current spreading from buildings or structures. They can be welding inverters, cathode protection systems and other devices. The current tends to follow the path lowest indicator resistance, as a result, with existing pipelines in the ground, it will be much easier for current to pass through the metal. The anode is the section of the pipeline from which the stray current exits to the soil surface. The part of the pipeline into which the current enters acts as a cathode. On the described anodic surfaces, the currents have increased density, therefore, it is in these places that significant corrosion spots form. The corrosion rate is not limited and can be up to 20 mm per year.
• Rust formation under the influence of alternating current. When located near power lines with a network voltage of over 110 kV, as well as in a parallel arrangement of pipelines, corrosion occurs under the influence of alternating currents, including corrosion under the insulation of pipelines.

Stress Corrosion Cracking

If a metal surface is simultaneously exposed to external negative factors and high voltage from power lines, creating tensile forces, then rust formation occurs. According to the research carried out, the new hydrogen-corrosion theory gained its place.

Small cracks are formed when the pipe is saturated with hydrogen, which then ensures an increase in pressure from the inside to levels higher than the required equivalent of the bond of atoms and crystals.

Under the influence of proton diffusion, hydrogenation of the surface layer occurs under the influence of hydrolysis at elevated levels cathodic protection and simultaneous exposure to inorganic compounds.

After the crack opens, the rusting process of the metal accelerates, which is provided by the ground electrolyte. As a result, under the influence of mechanical influences, the metal undergoes slow destruction.

Corrosion due to microorganisms

Microbiological corrosion is the process of rust formation on a pipeline under the influence of living microorganisms. These can be algae, fungi, bacteria, including protozoa. It has been established that the proliferation of bacteria most significantly influences this process. To maintain the vital activity of microorganisms, it is necessary to create conditions, namely nitrogen, humidity, water and salts. Also the conditions are:

1. Temperature and humidity indicators.
2. Pressure.
3. Availability of lighting.
4. Oxygen.

When selected acidic environment organisms can also cause corrosion. Under their influence, cavities appear on the surface, which are black in color and bad smell hydrogen sulfide. Sulfate-containing bacteria are present in virtually all soils, but the rate of corrosion increases as their numbers increase.

What is electrochemical protection

Electrochemical protection of pipelines against corrosion is a set of measures aimed at preventing the development of corrosion under the influence of electric field. Specialized rectifiers are used to convert direct current.

Protection against corrosion is carried out by creating an electromagnetic field, as a result of which a negative potential is acquired or the area acts as a cathode. That is, a section of steel pipelines, protected from rust formation, acquires a negative charge, and the grounding becomes positive.

Cathodic protection of pipelines against corrosion is accompanied by electrolytic protection with sufficient conductivity of the medium. This function is performed by soil when laying metal underground highways. Contacting of the electrodes is carried out through conductive elements.

The indicator for determining corrosion indicators is a high-voltage voltmeter or corrosion gauge. Using this device, the indicator between the electrolyte and the soil is monitored, specifically for this case.

How is electrochemical protection classified?

Corrosion and protection of main pipelines and tanks from it are controlled in two ways:

• TO metal surface supply the source from the current. This area acquires a negative charge, that is, it acts as a cathode. Anodes are inert electrodes that have nothing to do with design. This method is considered the most common, and electrochemical corrosion does not arise. This technique is aimed at preventing the following types of corrosion: pitting, due to the presence of stray currents, crystalline type of stainless steel, as well as cracking of brass elements.
• Galvanic method. Protection of main pipelines or sacrificial protection is carried out by metal plates with high levels of negative charges, made of aluminum, zinc, magnesium or their alloys. Anodes are two elements, so-called inhibitors, while the slow destruction of the protector helps maintain the cathode current in the product. Protective protection is used extremely rarely. ECP is performed on the insulating coating of pipelines.

About the features of electrochemical protection

The main cause of pipeline destruction is the result of corrosion of metal surfaces. After rust forms, cracks, ruptures, and cavities form, which gradually increase in size and contribute to the rupture of the pipeline. This phenomenon occurs more often near highways laid underground or in contact with groundwater.

The principle of cathodic protection is the creation of a voltage difference and the action of the two methods described above. After carrying out measuring operations directly at the location of the pipeline, it was found that the required potential to help slow down the destruction process should be 0.85V, and for underground elements this value is 0.55V.

To slow down the corrosion rate, the cathode voltage should be reduced by 0.3V. In this situation, the corrosion rate will not exceed 10 microns/year, and this will significantly extend the service life of technical devices.

One of significant problems– this is the presence of stray currents in the soil. Such currents arise from the grounding of buildings, structures, rail tracks and other devices. Moreover, it is impossible to make an accurate assessment of where they may appear.

To create a destructive effect, it is enough to charge steel pipelines with a positive potential in relation to the electrolytic environment, these include pipelines laid in the ground.

In order to provide the circuit with current, it is necessary to supply an external voltage, the parameters of which will be sufficient to break through the resistance of the soil foundation.

As a rule, such sources are power lines with power ratings from 6 to 10 kW. If electric current cannot be supplied, then diesel or gas generators can be used. The installer for the protection of underground pipelines from corrosion must be familiar with the design solutions before performing work.

Cathodic protection

To reduce the percentage of rust on the surface of pipes, electrode protection stations are used:

1. Anode, made in the form of grounding conductors.
2. Converters of constant electron flows.
3. Equipment for process control and monitoring of this process.
4. Cable and wire connections.

Cathodic protection stations are quite effective; when directly connected to a power line or generator, they provide an inhibitory effect of currents. This ensures protection of several sections of the pipeline simultaneously. Parameters can be adjusted manually or automatically. In the first case, transformer windings are used, and in the second, thyristors are used.

The most common in Russia is the high-tech installation - Minevra -3000. Its power is sufficient to protect 30,000 m of highways.

Advantages of the technical device:

• high power characteristics;
• updating the operating mode after overloads in a quarter of a minute;
• using digital regulation, operating parameters are monitored;
• tightness of highly critical connections;
• connecting the device to remote control behind the process.

ASKG-TM are also used, although their power is low, their equipment with a telemetry complex or remote control allows them to be no less popular.

A diagram of the insulation main of the water supply or gas pipeline must be available at the work site.

Video: cathodic protection against corrosion - what is it and how is it performed?

Corrosion protection by installing drainage

The corrosion protection installer for underground pipelines must be familiar with the drainage system. Such protection against the formation of rust of pipelines from stray currents is carried out by a drainage device necessary to divert these currents to another section of the earth. There are several drainage options.

Types of execution:

1. Executed underground.
2. Direct.
3. With polarities.
4. Reinforced.

When carrying out earth drainage, electrodes are installed in the anode zones. To ensure a straight drain line, an electrical jumper is installed connecting the pipeline to negative pole from current sources, for example, grounding from a residential building.

Polarized drainage has one-way conductivity, that is, when positive charge on the ground loop it is automatically switched off. Enhanced drainage operates from a current converter, additionally connected to the electrical circuit, and this improves the removal of stray currents from the main line.

The increase for pipeline corrosion is carried out by calculation, according to the RD.

In addition, inhibitor protection is used, that is, a special composition is used on the pipes to protect against aggressive environments. Standstill corrosion occurs when boiler equipment is idle for a long time To prevent this from happening, equipment maintenance is necessary.

An installer for the protection of underground pipelines from corrosion must have knowledge and skills, be trained in the Rules and periodically undergo a medical examination and pass exams in the presence of an inspector from Rostechnadzor.

Protection of gas pipelines from corrosion is divided into passive and active.

Passive protection. This type of protection involves insulating the gas pipeline. In this case, a coating based on bitumen-polymer, bitumen-mineral, polymer, ethylene and bitumen-rubber mastics is used. Anti-corrosion coating must have sufficient mechanical strength, ductility, good adhesion to pipe metal, have dielectric properties, and it must not be destroyed by biological influences and contain components that cause corrosion of pipe metal.

One of the widely used methods of passive protection is insulation with adhesive polymer tapes with a width of 400, 450, 500 mm or upon request. According to GOST 20477-86, depending on the thickness of the tape, its base can be grade A or B.

Active protection. Methods of active protection (cathodic, protective, electrical drainage) mainly come down to the creation of such electric mode for a gas pipeline, in which corrosion of the pipeline stops.

Rice. 1. Cathodic protection scheme:

/ - drainage cable; 2 — direct current source; 3 — connecting cable; 4 — ground electrode (anode); 5 - gas pipeline; b — drainage point

Cathodic protection. With cathodic protection (Fig. 1), an external power source is used to create a galvanic pair 2. In this case, the cathode is gas pipeline 5, connected at the drainage point 6 via a drain cable to the negative electrode of the power source; the anode is a metal rod 4, buried in the ground below its freezing zone.

One cathode station provides protection for a gas pipeline up to 1,000 m long.

Protective (electrode) protection. With sacrificial protection, a section of the gas pipeline is converted into a cathode not due to the power source, but through the use of a protector. The latter is connected by a conductor to the gas pipeline and forms a galvanic couple with it, in which the gas pipeline is the cathode and the protector is the anode. A metal with a more negative potential than iron is used as a protector.

The operating principle of the tread protection is shown in Fig. 2. Current from the protector 3 through the ground it enters the gas pipeline 6, and then along an insulated connecting cable to the protector. The protector will collapse when current drains from it, protecting the gas pipeline.

The coverage area of ​​the protector installation is approximately 70 m. The main purpose of the protector installations is to complement drainage or cathodic protection on remote gas pipelines for complete removal of positive potentials.

Rice. 2. Scheme of tread (electrode) protection:

/ - control point; 2 — connecting cables; 3 — protector (electrode);

4 — filler (salts + clay + water); 5 — paths of protective current movement in the ground; 6 — gas pipeline

Electrical drainage protection. With electrical drainage protection, the current is diverted from the anode zone of the gas pipeline to the source (rail or negative bus of the traction substation). The protection zone is about 5 km.

Three types of drainage are used: direct (simple), polarized and reinforced.

Direct drainage is characterized by bilateral conductivity (Fig. 3). The drain cable is connected only to the minus bus. Main disadvantage consists in the emergence of a positive potential on the gas pipeline when the butt joints of the rails are broken, therefore, despite their simplicity, these installations are not used in urban gas pipelines.

Polarized drainage has one-way conductivity from the gas pipeline to the source. When a positive potential appears on the rails, the drainage cable is automatically switched off, so it can be connected to the rails.

Rice. 3. Scheme of direct (simple) drainage:

/ - protected gas pipeline; 2 — adjusting rheostat; 3 - ammeter; 4 — fuse; 5 — negative bus (suction cable)

Enhanced drainage is used when the gas pipeline remains at a positive or alternating potential with respect to the ground, and the rail potential at the current drainage point is higher than the gas pipeline potential. In enhanced drainage, they additionally include in the circuit emf source, allowing you to increase the drainage current. The grounding in this case is the rails.

Insulating flange connections and inserts. They are used in addition to electrochemical protection devices and allow the gas pipeline to be divided into separate sections, reducing the conductivity and strength of the current flowing through the gas pipeline. Electrical insulating connections (EIS) are gaskets between rubber or hard rubber flanges. Inserts made of polyethylene pipes are used to separate various underground structures from each other. Installing an EIS leads to a reduction in energy costs by eliminating current flow losses to adjacent communications. EIS is installed at inputs to consumers, underground and overwater passages of gas pipelines through obstacles, as well as at inputs of gas pipelines to gas distribution stations, hydraulic fracturing and GRU.

Electrical jumpers. Electrical jumpers are installed on adjacent metal structures in the case when one structure has positive potentials (anode zone), and the other has negative potentials (cathode zone), while negative potentials are installed on both structures. Jumpers are used when laying gas pipelines of various pressures along one street.

They allow you to extend the service life of a metal structure, as well as preserve its technical and physical properties during operation. Despite the variety of methods for ensuring anti-corrosion action, it is possible to completely protect objects from rust damage only in rare cases.

The effectiveness of such protection depends not only on the quality of the tread technology, but also on the conditions of its application. In particular, to preserve the metal structure of pipelines, their best properties demonstrates electrochemical corrosion protection based on cathode performance. Preventing the formation of rust on such communications, of course, is not the only area of ​​application of this technology, but based on the totality of its characteristics, this area can be considered as the most relevant for electrochemical protection.

General information about electrochemical protection

Protection of metals from rust through electrochemical action is based on the dependence of the size of the material on the rate of the corrosion process. Metal structures must be operated in the potential range where their anodic dissolution will be below the permissible limit. The latter, by the way, is determined by the technical documentation for the operation of the structure.

In practice, electrochemical corrosion protection involves connecting a direct current source to the finished product. Electric field on the surface and in the structure of the protected object forms the polarization of the electrodes, due to which the process of corrosion damage is controlled. In essence, the anodic zones on a metal structure become cathodic, which allows negative processes to be displaced, ensuring the preservation of the structure of the target object.

Operating principle of cathodic protection

There is cathodic and anodic protection of the electrochemical type. The first concept, which is used to protect pipelines, has gained the most popularity. By general principle, upon implementation this method A current with a negative pole is supplied to the object from an external source. In particular, a steel or copper pipe can be protected in this way, as a result of which polarization of the cathode sections will occur with the transition of their potentials to the anodic state. As a result, the corrosion activity of the protected structure will be reduced to almost zero.

In this case, cathodic protection can also have different options execution. The above-described technique of polarization from an external source is widely practiced, but the method of deaerating the electrolyte by reducing the rate of cathodic processes, as well as creating a protective barrier, also works effectively.

It has been noted more than once that the principle of cathodic protection is implemented through an external current source. Actually, his job is main function These tasks are performed by special stations, which, as a rule, are part of the general infrastructure maintenance pipelines.

Anti-corrosion stations

The main function of the cathode station is to stably supply current to the target metal object in accordance with the method cathodic polarization. Such equipment is used in the infrastructure of underground gas and oil pipelines, in water supply pipes, heating networks, etc.

There are many varieties of such sources, and the most common cathodic protection device contains:

• current converter equipment;
• wires for connecting to the protected object;
• anode grounding conductor.

At the same time, there is a division of stations into inverter and transformer. There are other classifications, but they are focused on segmenting installations either by area of ​​application or by technical specifications and input data parameters. Basic principles The works most clearly illustrate the two types of cathode stations indicated.

Transformer cathodic protection installations

It should immediately be noted that this type stations is obsolete. It is being replaced by inverter analogues, which have both pros and cons. One way or another, transformer models are used even at new points for providing electrochemical protection.

A low-frequency 50 Hz transformer is used as the basis for such objects and the simplest devices are used for the thyristor control system, including phase-pulse power regulators. A more responsible approach to solving control problems involves the use of controllers with wide functionality.

Modern cathodic protection against corrosion of pipelines with such equipment allows you to adjust the parameters of the output current, voltage indicators, and also equalize the protective potentials. As for the disadvantages of transformer equipment, they boil down to a high degree of current ripple at the output with a low power factor. This flaw is not explained by the sinusoidal shape of the current.

The problem with pulsation can be solved to a certain extent by introducing a low-frequency choke into the system, but its dimensions correspond to the dimensions of the transformer itself, which does not always make such an addition possible.

Inverter cathodic protection station

Inverter-type installations are based on pulsed high-frequency converters. One of the main advantages of using stations of this type is the high efficiency, reaching 95%. For comparison, for transformer installations this figure reaches 80% on average.

Sometimes other advantages come to the fore. For example, the small dimensions of inverter stations expand the possibilities for their use in difficult areas. There are also financial advantages, which are confirmed by the practice of using such equipment. Thus, inverter cathodic protection against pipeline corrosion quickly pays for itself and requires minimum investment into technical content. However, these qualities are clearly noticeable only when compared with transformer installations, but today more efficient new means of providing current for pipelines are appearing.

Designs of cathode stations

Such equipment is presented on the market in different cases, shapes and dimensions. Of course, the practice of individual design of such systems is also widespread, which allows not only to obtain an optimal design for specific needs, but also to ensure the necessary operational parameters.

Rigorous calculation of the station’s characteristics makes it possible to further optimize the costs of its installation, transportation and storage. For example, for small objects, cathodic protection against corrosion of pipelines based on an inverter weighing 10-15 kg and a power of 1.2 kW is quite suitable. Equipment with such characteristics can be serviced and a passenger car, however, for large-scale projects, more massive and heavier stations can be used, requiring the connection of trucks, a crane and installation teams.

Protective functionality

When developing cathode stations, special attention is paid to protecting the equipment itself. For this purpose, systems are being integrated to protect stations from short circuits and load breaks. In the first case, special fuses are used to handle emergency operation modes of installations.

As for voltage surges and breaks, the cathodic protection station is unlikely to be seriously damaged by them, but there may be a danger of electric shock. For example, if in normal mode the equipment is operated at low voltage, then after a break the jump in the readings can reach 120 V.

Other types of electrochemical protection

In addition to cathodic protection, electrical drainage technologies, as well as protective methods for preventing corrosion, are also practiced. Most promising direction It is considered to be special protection against the formation of corrosion. In this case, active elements are also connected to the target object, ensuring the transformation of the surface with cathodes through current. For example, a steel pipe as part of a gas pipeline can be protected by zinc or aluminum cylinders.

Conclusion

Methods of electrochemical protection cannot be considered new and, especially, innovative. The effectiveness of using such techniques in the fight against rusting processes has been mastered for a long time. However, one serious drawback prevents the widespread use of this method. The fact is that cathodic protection against corrosion of pipelines inevitably produces so-called They are not dangerous for the target structure, but can have negative impact to nearby objects. In particular, stray current contributes to the development of the same corrosion on the metal surface of adjacent pipes.