Epoxy coal tar anti-corrosion steel pipe

Definition and composition of epoxy coal tar anti-corrosion steel pipe

Epoxy coal tar asphalt anti-corrosion steel pipe is a pipeline material coated with a two-component anti-corrosion coating mainly composed of epoxy resin and coal tar asphalt. Its anti-corrosion layer is reinforced with glass fiber cloth to form a protective structure with excellent mechanical properties and corrosion resistance. It is often divided into different grades such as ordinary grade (one cloth and two oils), reinforced grade (two cloths and three oils), and extra reinforced grade (three cloths and four oils). This material combines the high adhesion and chemical resistance of epoxy resin with the water resistance and microbial erosion resistance of coal tar pitch.

Structure and Construction Technology of Anti corrosion Coating

The anti-corrosion layer is achieved by layering epoxy coal tar coating and wrapping it with glass cloth. For example, the reinforced anti-corrosion layer adopts an alternating stacking method of "primer+glass cloth+topcoat". During construction, sandblasting and rust removal (Sa2 level or higher) should be carried out on the surface of the steel pipe, and primer and topcoat should be applied in a dry environment. Epoxy coal tar coating should be mixed with curing agent in proportion, and the construction temperature should be controlled above 5 ℃ to avoid rain, snow or high humidity environments. After coating, it is necessary to use electric spark to detect pinholes and repair them, ultimately forming a dense, smooth, and anti-seepage anti-corrosion layer.

Performance characteristics and advantages

This material has the following core properties: acid, alkali, salt corrosion resistance, seawater erosion resistance, resistance to plant root penetration, excellent wear resistance, and the coating has the same thermal expansion coefficient as the steel pipe, making it difficult to crack and peel off. Its anti-corrosion time can reach more than 20 years, and with cathodic protection technology, its durability can be further improved. Compared to traditional petroleum asphalt, it has lower water absorption and stronger microbial resistance, making it suitable for underground, underwater, and high-temperature (100 ℃ -150 ℃) environments. In addition, the room temperature curing characteristics facilitate on-site construction, and the mechanical strength is significantly improved after glass cloth reinforcement.

Main application areas

Widely used for external anti-corrosion of buried or underwater oil, gas, water, and heating pipelines, as well as chemical storage tanks, dock steel structures, sewage treatment tanks, coal mine shafts, and other scenarios. In the field of oil and gas, it complements 3PE anti-corrosion technology; In urban water supply and drainage engineering, it can effectively deal with soil microorganisms and stray current corrosion. Specially designed temperature resistant products can also meet the transportation needs of high-temperature media.

Market and Quality Control

The price of epoxy coal tar anti-corrosion steel pipes is affected by the pipe diameter and anti-corrosion grade. Production must comply with industry standards such as SY/T0447-96, and undergo quality control processes such as visual inspection, thickness measurement, and electrical discharge testing. Market data shows that its cost-effectiveness is better than some new anti-corrosion technologies, especially widely used in small and medium-sized pipelines and complex terrain engineering. In recent years, demand has continued to grow under the promotion of environmental policies.