Corrosion refers to the natural destruction of metals or the decline of their properties because of environmental factors. Similar to other natural incidents corrosion can be extremely dangerous and can lead to high costs to repair damage.
There are various types of corrosion like:
- Chemical- occurs without electric current
- Electrochemical- corrosion current
- Mechanic – chemical
External side of tank- under the atmospheric moisture and other factors the tank stains.
Internal side of the tank- This depends on the frequency of the tanks loading, chemical composition of the products and amount of water present in the product.
Inside tank corrosion tends to happen faster than the external surface.
Painting of the tanks surface:
Based on various rules of the construction of the tank the external surface of above ground tanks must be maintained regularly. They must be painted with lacquer paint materials. It is important to consider the light reflection factor while choosing the colour of the corrosion protection coating of the tank.
Preparation of the external surface of a vertical tank:
Before applying a new coat of corrosion protection, it is essential to remove the old layers of the protective coat, traces of corrosion and dirt either manually or using special machines made for the same purpose. Post this a cleaner is applied on the stained surface for 3-5 mins and is washed with hot water with the corrosion products.
The entire outside surface of the tank is degreased and cleaned. It is extremely important to wipe and dry the whole surface at every stage.
Technological process of applying the industrial coating:
Once the external tank surface is prepared after cleaning, an industrial priming coating is applied with a pneumatic spray gun. Avoiding paint drips is important. This process helps in protecting the metal from corrosion and ensuring adherence of paint coating with the metal.
Soil corrasion protection of the tank bottom:
Penetrating corrosion bottom destruction of the tanks may lead to spills that pollute the environment which may lead to serious problems. The soil corrosion can be avoided by arranging a water proof layer and using electro- chemical protection. Cathodic protection can effectively help protect the tank bottom. The following requirements of protecting the tank bottom should be kept in mind:
- The foundation and basement of the tank should provide room for the drainage of ground water and precipitation from under the tank.
- It is extremely important to consider the environmental protection regulations safety regulations and other standards for this.
Electro chemical corrosion protection:
This refers to the protection of the storage tank based on the ability of metals to stop staining under the influence of flow of direct current. Sea water, local water and bottom water all contribute to the corrosion of the tank. This is the best type of corrosion protection and is extremely effective method against the most local type of metal corrosion. There is also a treat of over-protection which is connected with release of hydrogen and other effects.
Industrial painting of the internal tank surface:
This is an extremely labor-intensive task and has a complicated procedures and application of the protection coating.
A priming coat is applied on the pre-prepared internal surface of the tank with a spray gun, paint drips are avoided. The surface is covered with paint and lacquer materials with 2-4 layers which are dried individually.
