Introduction of anticorrosive coating-asphalt coating

Asphalt coating is one of the most important anticorrosive coatings,especially coal tar pitch is the best.Asphalt coating can be used both externally and internally on carbon steel pipes.It is usually black,and when applied properly,this coating offers outstanding cathodic protection needed for almost all structural steel pipes situated underground.It is regarded as one of the least expensive ways to provide cathodic protection to pipes.It is also the least complex coating process, making it suitable for casing pipes like in road bore.

Anticorrosive coating asphalt coating steel pipes

Anticorrosive coating asphalt coating steel pipes

Coal tar pitch coating is low in price and also has the following advantages:

Firstly, water resistance. Its water absorption is only 0.1%-0.2% after immersion in water for 10 years;

Secondly,it is erosion resistance to some chemical media;

Thirdly, it has well wettability on the surface of steel which has not been fully rust-cleaned; What’s more,it has high solid content, so thick film can be obtained;

Last but not the least, coal tar pitch coating is not expensive. It also has shortcomings.Coal tar pitch coating is crisp in winter and soft in summer. After sunlight exposure, some components will volatilize and release, which may cause cracking of paint film. These shortcomings can be improved by adding some other resins.For example,adding chlorinated rubber can enhance the dryness of asphalt coatings,avoid crispness in winter and softness in summer.Epoxy asphalt coatings made by adding epoxy resin can have both the advantages of asphalt coatings and epoxy coatings,obtaining very satisfactory results in anti-corrosion.Asphalt coatings have been used in container bottoms, ship bottoms,dock gates,cofferdams and other occasions.

As for petroleum asphalt, the anti-corrosion performance of the coating is good, but the coating is coated in a flowing state,so the quality can not be guaranteed.Petroleum asphalt is sensitive to temperature.It will flow when the temperature is high and becomes brittle when temperature is low.Petroleum asphalt has the characteristics of fast aging,poor durability,poor microbial corrosion resistance,easy to be broken by plant roots,and easy to be bruised when lifting transported.

Our company-Hebei Haihao High Pressure Flange & Pipe Fitting Group can produce various kinds of anticorrosive coatings to meet your specific demands,such as 3PE,FBE,etc.We are committed to providing you with superior products with appropriate coatings. Contact us for more details,