3PE anti-corrosion steel pipe heat shrink sleeve in the mid to late nineties began to be used in the oil and gas industry for long-distance transportation of oil and natural gas steel pipe weld anticorrosion at the beginning of this century and a large number of applications in the long-distance transmission of oil and natural gas steel pipe weld anticorrosion, city gas pipeline network seam anticorrosion, heat supply steel pipe seam anticorrosion, water pipe seam anticorrosion and other fields. This paragraph from the meaning of steel pipe corrosion. The current situation of corrosion of oil and gas transmission steel pipe Introduction of heat shrink sleeve for oil and gas transmission steel pipe anti-corrosion, requirements of 3PE heat shrink sleeve for oil and gas transmission steel pipe anti-corrosion, application prospect of 3PE heat shrink sleeve for anti-corrosion in oil and gas industry are five aspects about the application of 3PE heat shrink sleeve in steel pipe anti-corrosion.

I. Corrosion prevention significance of steel pipeline
　　Steel pipe corrosion problem is widespread in all sectors of the national economy and national defense construction, both to the national economy has brought huge losses. Also to production and life caused great difficulties. Steel pipe in the natural conditions (atmosphere, natural water, soil) or man-made conditions (acid, alkali, salt and other media), every moment in the occurrence of corrosion. A spontaneous and unnecessary consumption. The root cause of steel pipes because in a thermodynamically unstable state, in the above conditions they have to restore the original relatively stable state. Generation of iron oxides carbonates, etc.. Or transformed into soluble ions. This process is the corrosion process of metals. According to statistics, China’s annual output of steel 1.6 billion tons. More than 60 million tons of annual loss due to corrosion. Almost equal to the annual output of the Shanghai Baosteel Iron and Steel General Factory. Corrosion is not only a waste of steel resources, but also due to corrosion so that the pipeline, equipment, conventional use of shortened life replacement of new pipeline equipment cost far more than the price of the metal material itself, the cost of production thus increased, reducing the economic benefits Corrosion caused by direct and indirect economic losses is huge. Corrosion products form a scale layer, affecting heat transfer and media flow rate, heat transfer efficiency is reduced, energy consumption is greatly increased, China’s annual economic losses caused by corrosion up to 280 billion yuan, more than the annual wind, floods, earthquakes, fires and other natural disasters combined.
　　Corrosion caused by a variety of accidents and major disasters. Due to the corrosion of steel pipelines, equipment, causing the production enterprises to stop work and production quality decline. Affect the life of the supply, gas, heating steam or hot water, bringing a lot of difficulties to people’s lives. Buried oil and gas, water and other pipelines, pipeline network leaks, enterprises refining, chemical, chemical fiber, fertilizer, pharmaceutical and other pipelines, equipment, run, bubble, drip. In addition to the loss of a large number of useful materials and cause serious environmental pollution, and even cause fires, explosions, collapses and other catastrophic accidents. In view of the prevalence of metal corrosion. To avoid or slow down the occurrence of metal corrosion. A variety of metal corrosion technology and technology came into being. The promotion and application of new metal corrosion technology, new materials and new equipment. Extend the life of the regular use of pipeline equipment, save money and ensure safe production. China’s petroleum, chemical, public utilities and other industries. Pipeline perforation due to corrosion up to 20,000 times / year. Its main occurrence in the interface of the steel pipe and the pipeline itself bumping injury.
Second: oil and gas transmission steel pipeline corrosion status
　　According to the survey statistics, in China’s pipeline accidents, the damage caused by corrosion accounts for about 3O%. Several oil fields in the east of China all kinds of pipelines due to corrosion perforation of 20,000 times / year, the number of replacement pipeline 400 km / year. Sichuan natural gas pipeline, May 1971 ~ May 1986 15 years asked due to corrosion caused by the explosion and combustion accidents amounted to 83, economic losses amounted to more than 600 million. 1993 only in the production system of crude oil fields due to corrosion generated economic losses amounted to 1.6 billion yuan. China’s petrochemical industry in 1989 due to corrosion caused by the economic loss of about 2 billion yuan.
1, oil and gas pipeline corrosion principle and factors affecting: long oil and gas pipeline less than a few hundred kilometers, a few thousand kilometers long. Through the different soil rivers, lakes, due to the multi-phase nature of the soil. Freezing and melting in winter and summer． Underground water level changes, plant roots on the penetration of the coating microorganisms stray currents and other complex buried conditions to the pipeline caused by complex corrosion ring organic sulfides, salt, groundwater, minerals oxygen. China’s oil and gas field production and city gas pipeline network in the corrosion encountered, the vast majority of electrochemical corrosion. Soil corrosion principle belongs to electrochemical corrosion. The main factors affecting soil corrosion are soil resistivity, soil oxidation potential, salt content, water and air content, soil temperature, acidity microorganisms, stray currents
2, oil and gas pipeline corrosion technology: buried oil and gas pipeline corrosion forms are usually pipeline corrosion, pipeline corrosion, pipeline cathodic protection, above-ground pipeline corrosion. Requirements for buried pipeline external anti-corrosion coating: has a very good resistance to soil, water, mold corrosion and construction performance. Have good electrical insulation. When used jointly with cathodic protection, the anti-corrosion coating should have a certain ability to resist cathodic stripping strength. Have sufficient mechanical strength. To ensure that the coating in handling and soil pressure under the action of no damage. Buried steel pipe external anti-corrosion coating technology are petroleum asphalt anti-corrosion layer, epoxy coal asphalt anti-corrosion coating, coal tar enamel anti-corrosion coating, polyethylene adhesive tape, fusion bonded epoxy powder anti-corrosion coating, two-layer PE anti-corrosion coating, three-layer PE anti-corrosion coating, polyurethane rigid foam anti-corrosion insulation composite structure. The latter three methods are commonly used methods.
Corrosion type of buried steel
Usually buried steel pipe buried in the ground for a long time, there will be some corrosion of the situation, so what are the types of corrosion for complex conditions?
① outside the pipeline corrosion outside the pipeline corrosion causes include external corrosion layer of the external corrosion layer, the quality defects of the external corrosion layer, the quality defects of the steel pipe, the pipeline buried in the soil environment corrosion.

② pipeline stress corrosion rupture pipeline in the tensile stress and specific corrosive environment produced by low stress brittle rupture phenomenon known as stress corrosion rupture.

③ pipeline corrosion of this type of corrosion factors are relatively single, mainly by the impact of the physical and chemical properties of the transported media and impurities, the corrosion that occurs is mainly electrochemical corrosion.

For example: if the transported natural gas humidity and high sulfur content, the pipeline is easy to occur in the electrochemical corrosion. For this type of corrosion mechanism research is more mature, the results caused by corrosion in the pipeline is basically predictable, so the treatment method is also standardized. For example, through dehumidification and desulfurization, or increase the corrosion inhibitor can eliminate or slow down the occurrence of internal corrosion. In recent years, with the pipeline owners to strengthen the management of pipeline operation and the strict requirements of the transport medium, internal corrosion has been controlled to a large extent. At present, the main development trend of long-distance oil and gas pipeline corrosion control at home and abroad is in the external corrosion, so the pipeline inspection also focuses on the coating defects and pipeline defects caused by external corrosion.