3LPE Anti-Corrosive Steel Pipe Can Be Used for Up to 50 Years

The technology of 3LPE anti-corrosive steel pipe (three layer PE) is a a kind of advanced anti-corrosion technology introduced from abroad in the late 1990s. it's full name is the fusion bonded epoxy/extruded polyethylene protective layer structure. 3LPE anti-corrosion technology combines the excellent performance of epoxy coating and extruded polyethylene anti-corrosive coating so as to significantly improve its performance. It has characteristics of high mechanical strength, wear resistance, corrosion resistance, heat resistance and cold resistance, which can be applied to 150° medium in cold zone. Therefore, 3PE coating is the ideal outer protective layer of buried pipeline. According to the detection of authoritative department, the service life of buried pipe with 3 PE anti-corrosive coating is up to 50 years.

In three layer structure, the main function of fusion bonded epoxy powder coating are: to form a continuous film, directly be bonded with the surface of steel tube, has the very good resistance to chemical corrosion and cathodic dis-bonding resistance; To form chemical bonding by reacted with the-middle-layer adhesive, ensuring that the overall coating has good caking in the case of higher temperatures. The middle layer usually is copolymer adhesive, whose main composition is polyolefin. Vinyl copolymer adhesive is currently widely used. The functional groups in polar part of copolymer adhesive and the epoxy groups of fusion bonded epoxy powder coating can react to generate hydrogen bond or bonds, forming a good bond between middle layer and bottom layer; And the non-polar polyethylene part has good interaction with superficial polarity, so there is also a good adhesive performance between the middle layer and the superficial layer. The main function of superficial polyethylene layer is to effect mechanical protection and anti-corrosion, which has the same effect with the traditional two-layer-structure polyethylene anti-corrosive coating.

3LPE anti-corrosive coating (three layers of polyethylene anti-corrosive coating) combines 2PE anti-corrosive coating from Europe with epoxy powder anti-corrosive coating (FBE) widely used in North America to produce a new kind of anti-corrosive coating for steel pipe. It has been recognized and used all over the world for more than ten years. Thereby the difference is epoxy powder layer is added in 3LPE anti-corrosive coating. The epoxy powder layer has good mechanical properties and strong cathodic dis-bonding resistance. Although it needs a strict surface treatment, has poor weather resistance and bibulous rate, it is suitable for buried pipe in undersea pipeline. The thickness of coating layer is only 0.3 ~ 0.5 mm, the period of validity can reach 40 ~ 50 years.
  
3LPE anti-corrosive coating of steel pipe means that the bottom layer is in contact with the steel tube surface by epoxy powder anti-corrosive coating, the middle layer is copolymer adhesive consisting of  branching structure with functional groups, the superficial layer is high-density polyethylene anti-corrosive coatings. 3LPE anti-corrosive coating has high permeability, high mechanical properties, etc. of epoxy resin and polyethylene material. So far, it is the world recognized anti-corrosion coating of pipeline with performance and it has been applied in many engineering.