Several pipeline anticorrosion coatings and their respective advantages and disadvantages
At present, pipeline anti-corrosion treatment methods are mainly based on various coatings for film protection, and the selection of suitable coatings is the key to pipeline anti-corrosion. The following ten main types of coatings are commonly used for pipeline anticorrosion.
1. Epoxy resin anti-corrosion coating.
Epoxy resin anti-corrosion coating is widely used for anti-corrosion of inner and outer walls of pipelines. Advantages: strong adhesion, acid and alkali resistance, low shrinkage, etc. Disadvantages: The paint film is easy to pulverize and has poor weather resistance.
2.Polyurethane anti-corrosion coating
Polyurethane anti-corrosion coating can be used for anti-corrosion on the inner wall of the pressure water pipe of the power station and the inner wall of the underground steel pipe of the oil field water injection well. Advantages: Polyurethane coatings are resistant to acid, alkali, oil, water and abrasion
3. Asphalt anti-corrosion coating.
The main purpose of asphalt coatings is waterproofing and anti-corrosion of underground pipelines. When used for anti-corrosion of underground pipelines, it is usually covered with glass cloth. Advantages: The price of raw materials is low, and it is resistant to corrosion of dilute acid and dilute alkali at room temperature. The paint film dries quickly and has good elasticity. Disadvantages: not resistant to organic solvents, low temperature embrittlement.
4. Urushiol anti-corrosion coating.
It can be used as an anti-corrosion coating for ammonia gas, ammonia water, chlorine gas and hydrogen sulfide gas; it can also be used as a moisture-proof and anti-corrosion coating for underground pipelines. Advantages: Compared with raw lacquer, it is less toxic and dries quickly. Acid resistance, alkali resistance, ammonia resistance, water resistance.
5. Olefin resin anti-corrosion coating
The coating is mainly made of resin containing ethylene or propylene molecular structure as raw material, plus modified resin, filler, etc. It has good water resistance, acid resistance, alkali resistance and weather resistance.
6. Perchlorethylene resin anti-corrosion coating.
It is a coating widely used in chemical pipelines to prevent atmospheric corrosion. Its disadvantage is that it has poor adhesion to pipes. In order to improve its adhesion, epoxy resin is commonly used to modify it, and a certain effect has been achieved.
7.Chlorinated rubber anti-corrosion coating.
Generally used for atmospheric corrosion protection, the effect is better. Its characteristic is that it can be more resistant to the corrosion of dilute acid and dilute alkali, has good permeability resistance, and is flame retardant.
8.High temperature resistant anti-corrosion coating.
High-temperature anti-corrosion coatings are mainly silicone resin heat-resistant coatings, which can be used at temperatures up to 500°C. The advantages are good water resistance, corrosion resistance, and weather resistance. The disadvantage is that the adhesion is poor, the price is expensive, and the products containing lead powder need to be dried
9.zinc-rich anti-corrosion coatings.
The anticorrosion principle of zinc-rich coatings is mainly that zinc powder can play a cathodic protection effect on steel materials, so it is suitable for anticorrosion of water, seawater, oil, and marine atmosphere, and it is not suitable for use in acid and alkali media.
10. Cement mortar.
Cement mortar is mainly used as the lining coating of water supply pipelines. At present, there are modified varieties such as polymer cement mortar, which can be applied to pipelines such as hot water, sea water, and sewage, and can inhibit the growth of microorganisms and bryophytes. Its advantages are economical and non-polluting.
