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The Using Of Cathodic Protection In Defend Chongqing Buried Steel Gas Pipeline To Corrode

Posted on:2009-11-25Degree:MasterType:Thesis
Country:ChinaCandidate:W Y JiangFull Text:PDF
GTID:2121360272973540Subject:Architecture and Civil Engineering
Abstract/Summary:PDF Full Text Request
The use of metal materials in the process of vulnerability to environmental effects over time and gradually extend the damage or performance degradation, according to the survey developed countries around the world each year due to corrosion loss of more than 700 billion dollars. Obviously, metal corrosion problem is very serious and common. China's natural gas pipeline material is now mostly used in steel pipe, Steel natural gas pipe buried in operation often have local corrosion perforation, which can cause accidents, and endanger people's lives and safety, so it is necessary and essential for the city gas pipeline to take anti-corrosion .Cathodic protection is a recognized anti-corrosion technology, its broad applications, which involve the ground, water and chemicals in the media pipeline, storage containers, port, shipping and chemical equipment, and other various aspects, especially in the buried steel pipeline, the wharf and the shipping, its anti-corrosion and other effects of anti-corrosion technology compared with irreplaceable role.On the basis of having looked up a great of home and abroad document , This paper have introduced the buried natural gas pipeline electrochemical corrosion of metals and anti-corrosion theory, analysed Chongqing natural gas pipeline from corrosion protective layer and the status quo, found out Various factor of influence soil.Through has implemented cathodic protection gas line's guard potential many year tests to Chongqing, has carried on the analysis to Chongqing gas line cathodic protection effect, will have certain guiding sense to the next Chongqing area steel gas line cathodic protection implementation. Through the testing of implementing for the protection of the natural gas pipeline cathodic protection potential many years ,having analyzed Chongqing gas line cathodic protection effect, this will have certain guiding sense to Chongqing area steel gas line cathodic protection implementationThrough this study, the main conclusions:①there are two kind of cathodic protection methods , sacrificial anode and mandatory Current Cathodic, to compare two methods of economic and technical , found that sacrificial anode apply mainly to Chongqing urban areas and shorter pipeline, the mandatory Current Cathodic apply mainly to long-distance pipelines.②the soil in Chongqing has strong corrosive environment, through the underground pipeline corrosion principle of an in-depth discussion ,connection with the Chongqing steel natural gas pipeline laying the soil environment reach the conclusion that: Chongqing steel natural gas pipeline corrosion belong to the electrochemical corrosion. Factors affecting the corrosion rate of major are: soil resistivity, soil moisture content, PH value, and so on.③Carries on the analysis to many Chongqing areas in the service natural gas pipeline soil electronic resistivity to obtain along the route, Chongqing area in service natural gas pipeline along the route soil electronic resistivity mostly in 20-100Ω·M, therefore suits in Chongqing area soil sacrifice anode is the magnesium anode.④Through the establishment gray forecast model, and carried on the effect analysis and the protection forecast to Chongqing gas pipeline cathodic protection, obtains Chongqing area to implement the cathodic protection the steel gas pipeline to receive the cathodic protection, achieves the country cathodic protection standard the request, simultaneously can achieve the cathodic protection movement design age limit, thus lengthened the steel pipeline's safety handling life.⑤gas pipeline coating has a good electrical insulation, adhesion, continuity and corrosion resistance, and other combination properties, the maintenance of its integrity is of utmost importance. Coating detection technology is the premise which is doing not open to dig to the piping bottom ,using special equipment on the ground non-contact coating on the comprehensive performance test, scientific, accurate and economical way of aging and damaged coating defect analysis, to guide the pipeline Owners of the pipeline coating the status of master, in the actual work of the wider application of detection technology include: standards / potential detection, Pearson testing, testing potential of space, multi-frequency in the current test, DC - Graded tests. But each have merit and shortcoming, adoption cathode protection electric potential first carry on valuation to coating quality is a kind of the most simple and direct method, When it have bigger blemish again make use of an other examination method to carry on fixed position, can have the function of half effort and double results.
Keywords/Search Tags:Corrosion, Potential Protection, Cathodic Protection, Sacrificing The Positive Pole
PDF Full Text Request
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