3PE anti-corrosion pipeline manufacturing process

3pe anti-corrosion steel pipe base material includes seamless steel pipe, spiral steel pipe, and straight seam steel pipe. the three-layer polyethylene (3pe) anti-corrosion coating has been widely used in the oil pipeline industry due to its good corrosion resistance, water vapor permeability resistance, and mechanical properties. the anti-corrosion layer of 3pe anti-corrosion steel pipe is very important for the life of buried pipelines. some pipes of the same material are buried underground for decades without corrosion, while others leak within a few years. it is because they use different outer anti-corrosion layers.

anti-corrosion structural steel pipe outer wall anti-corrosion form

3pe anti-corrosion generally consists of 3 layers:

the first layer of epoxy powder (fbe>100um)

the second layer of adhesive (ad) 170 ~ 250um

the third layer of polyethylene (pe) 2.5 ~ 3.7mm

in actual operation, the three materials are mixed and integrated, and after processing, they are firmly combined with the steel pipe to form an excellent anti-corrosion layer. its processing methods are generally divided into two types: winding type and round mold wrapping type.

3pe anti-corrosion steel pipe coating (three-layer polyethylene anti-corrosion coating) is a new anti-corrosion produced by ingeniously combining the european 2pe anti-corrosion coating and the epoxy powder anti-corrosion steel pipe coating (fbe) widely used in north america. steel pipe coating. it has been recognized and used all over the world for over ten years. the coating of 3pe anti-corrosion steel pipe is that the bottom layer and the steel pipe surface are in contact with epoxy powder anti-corrosion coating, and the middle layer is a copolymerized adhesive with branched functional groups. the surface layer is high-density polyethylene anti-corrosion coating. 3pe anti-corrosion coating combines the high impermeability and high mechanical properties of epoxy resin and polyethylene materials. up to now, it is a globally recognized pipeline anti-corrosion coating with effect and performance, which is used in many projects.

standard setting

in the early stage of introducing 3pe coating technology, cnpc engineering technology research institute compiled the first 3pe coating construction acceptance specification in china in april 1995 concerning din30670-1991 and nfa49-710 (march 1988 edition), which is used for the shaanxi-beijing pipeline, kushan pipeline construction. in the same year, it was upgraded to the industry standard sy/t4013-1995. after several years of summary and practice of engineering construction, it was revised to sy/t0413-2002 in 2001, and it was implemented on august 1, 2002. at the beginning of the formulation of the standard, according to the actual situation in china, high-density polyethylene is the main polyethylene, and the vicat softening point is set to be not less than 110 °c; the thickness of the outer anti-corrosion layer is based on the german standard of low and medium density polyethylene din30670-1991 to determine. the impact strength of the 3pe anti-corrosion coating is greatly improved, and the construction quality of the shaanjing pipeline and the kushan pipeline is guaranteed. according to the carbon black content of some special materials, the mechanical strength and weather resistance of the 3pe anti-corrosion layer is guaranteed, and the peeling strength of the patch (that is, the peeling strength of the heat shrinkable sleeve and heat shrinkable tape to the primer steel) is increased. contributed to ensuring the quality of the anti-corrosion coating on the outside of the pipeline.

project application

at present, 3pe anti-corrosion has successfully solved the problems of corrosion resistance and bump resistance of the outer wall of the steel pipe, but the inner wall anti-corrosion currently uses liquid epoxy coating ipn8710, which takes a long time to cure at room temperature, and the inner wall adopts a liquid ring. oxygen paint can only reduce drag, but cannot achieve corrosion resistance and scouring. if it is used in water pipelines, the inner wall must be in the form of thermal fusion epoxy resin powder, which can better improve the corrosion resistance and resistance of the inner wall. friction capacity. among them, the outer 3pe and inner sintered epoxy composite steel pipes used in the henan section of the middle route of the south-to-north water diversion project have been successfully applied to the supporting facilities of the south-to-north water diversion project. it solves the characteristics that the inner wall is not easy to scale, smooth, wear-resistant, and corrosion-resistant.