3pe corrosion seamless steel pipe for the country to increase domestic investment in 2015, much higher than 2008's four trillion investment environment in the country for a very favorable time 3pe 3pe seamless steel pipe spiral steel pipe manufacturer 3pe opportunities, we To be ready. 3PE anti-corrosion steel refers to three-layer structure of polyolefin coating (MAPEC) external corrosion steel pipe, is commonly used as a preservative pipeline. Generally refers to the pipe wall corrosion. There are other IPN8710, FBE epoxy powder, coal tar epoxy anti-corrosion methods. 3PE preservative composition generally consists of three layers: a first layer of epoxy hybrid powder (FBE> 100um) a second layer of adhesive (AD) 170 ~ 250um third layer of polyethylene (PE) 2.5 ~ 3.7mm in the actual operation of three kinds of materials com, after processing so that the pipe to form a solid combination of excellent corrosion layer. The processing methods are generally divided in two and wound sheathed round mold. 2PE / 3PE anti-corrosion pipe which is suitable for coal mine drainage, underground shotcrete, positive and negative pressure ventilation, gas drainage, fire sprinkler pipe network. Thermal power plant waste process water, backwater pipeline. For anti-sprinkler, water sprinkler system piping has excellent applicability. Electricity, telecommunications, highways and other cable protection sleeve. Suitable for high-rise building water supply, heat supply network, water supply projects, gas transportation, underground water and other pipelines. Oil pipelines, chemical and pharmaceutical, printing and dyeing industry, transport process piping of corrosive media. Sewage discharge pipes, sewers and biological corrosion engineering pool. Agricultural irrigation pipe, deep pipes, drains, etc., etc. Internet use, it can be said 3PE anti-corrosion steel in the current building is essential, and I believe that through the extension of technology, it still has a more brilliant future results. Petroleum Technology Academy of Engineering in the early introduction of 3PE coating technology, developed China's first acceptance 3PE coating construction in April 1995 and reference DIN30670-1991 NFA49-710 (1988 edition March), for the Shaanxi-Beijing pipeline , Kushan pipeline construction. In the same year upgraded to industry standard SY / T4013-1995, summary and practice a few years after construction, the 2001 revision of SY / T0413-2002, and implemented with effect from 1 August 2002. The beginning of the standards, according to the actual situation in China, high density polyethylene, polyethylene-based, Vicat softening point to no less than 110 ℃; the thickness of the outer coating of the press to a low, medium density polyethylene-based German standards DIN30670-1991 to determine. Greatly improve the impact strength 3PE coating, to ensure construction quality and libraries Shan Shaanxi-Beijing pipeline pipeline, SY / T0413-2002 turn 3PE coating peeling strength, impact indicators significantly improved and clearly defined According to some of special carbon black content, to ensure that the mechanical strength and weather resistance 3PE coating and mending increased peel strength (ie, heat shrink, peel strength of steel primer shrink band) frequency sampling tests for Quality assurance pipeline external corrosion coatings make a contribution. 3 reliable research on the use of 3PE coating controversy occurred in the country, Petroleum Engineering Technology Research Institute under Beijing China Oil & Gas Ltd. commissioned to complete the "Safety Evaluation of Shaanxi-Beijing gas pipeline external corrosion 3 layer polyethylene coating structural systems" . The study included the collection of foreign literature to the pipeline from the outer coating of oil and gas excavation inspection Beijing China Ltd. 2001-2003 excavation carried out and the results are not checking the analysis, and the Shaanxi-Beijing pipeline unused open dumps in North China Petroleum Steel Pipe 3PE anti-corrosion performance testing plant for 2 years and 6 years, the following conclusions: (1) coating applied at home and abroad Evaluation good few defects reported in its use. The main disadvantage of reports have dew point, peeling, cathodic stripping, cathodic protection shield, stripped down corrosion coating film, and most of the reports of defects still remain in the theoretical speculation stage, such as the information mentioned in the cathodic protection shield issue to There does not appear on the actual operation of the coating cathodic protection shield instances reported. After years of practice showed that with the increase of service life, minimal defects in the coating system is FBE / extruded polyethylene three-layer structure coating systems. (2) through the application of the European history of polyethylene coating 30-year review will occur corrosion or stress corrosion cracking under the coating peeling Although theoretically, but there is no film coating peeling occurs under stress corrosion or cracking cases occur . Mannesmann Research Institute in Germany, who conducted a long-term corrosion laboratory experiments to simulate the effect of the coating application. Corrosion test environment in soil, water, testing mainly the problem of stress corrosion cracking, corrosion is to the experimental defective polyethylene coating steel corrosion conditions and placed under stress conditions, corrosive environment containing NaHCO3 sandy environment, temperature 70 ℃ pipe ground -430 ~ -460mV, steel surface pretreated in different ways, all are under pressure pipe loop. End of the experiment, coating defects stripping around more or less, but the stripping zone is found corrosion. No skin surface of a steel pipe for oxygen stress cracking occurs, there appears a scale of steel cracking, the maximum crack depth of 0.2mm, may be caused by stress corrosion. It follows that the surface treatment is complete an effective means to prevent stress cracking. (3) 2003 Shaanxi-Beijing pipeline excavation 763m long pipe, 3PE coating a total of four break points. As can be seen from the point defects in the form of broken, damaged coating both are caused by a hard object to scratch. 3PE straight pipe and cold on the elbow three test pit inspection, were detected in 17 peel strength, which five peel strength values ??below 70N / cm, the minimum peel strength of 120N / cm, the maximum peel strength 200 N / cm. Cause for the Shaanxi-Beijing pipeline is the first time 3PE coating technology, the limited level of coating applicator, and the control of process engineering can stand relatively poor coating process may lead to improper settings of individual pipeline coating of sticky Relay poor. Coating peeling strength low just individual parts, but as long as the coating is not damaged, it will not cause pipeline corrosion. (4) 1999 and 2003 in North China Petroleum Steel Pipe Plant open storage of Shaanxi-Beijing pipeline corrosion remaining tube sampling tests conducted its antiseptic properties basically no decline, especially the adoption of Hualong Qilu polyethylene pipe corrosion produced, stored for 6 years After the indicators remain in line with the current standard SY / T0413-2002 regulations, instructions 3PE coating does have excellent durability and anti-aging properties. Comprehensive research conditions and test results Shaanxi-Beijing pipeline, the main flaw 3PE coating is mechanical damage during construction.