管道防腐 涂层

,anti-corrosionprotectionofburiedpipelines,-Anticorrosioncoatings,Contents,Selectionofthemosteconomicallyeffectivetechniqueforminimizingtheeffectsofcorrosionisacriticaldesigndecision.Thiscoursewillreviewfusionbonded-epoxy(FBE)coatingsolutionsforcorrosionmitigationofpipelinesystems,1.thefunctionofcoating,Usingthesesystemsisvitaltoprotectsteel.Coatingshelppreventcorrosionbyproviding:(1)Sacrificialorgalvanicprotection.(2)Passivationofthesteel(inhibitivepigments).(3)Abarrieragainsttheenvironment.,Varioustypesofcoating,Coatingsofpipelines:Hydrocarbonbitumen(hardcoaltar,asphalt)Polyethylene(2or3layers)PolypropyleneEpoxy（环氧树脂）Polyurethanefoam(聚氨酯泡沫)Coatingsoffittings:PolyurethaneorModifiedPolyurethane(projected)MouldedresinsPolyurethane（成型树脂聚氨酯）,Fieldjointscoatings(weldedjoints)（现场对接/连接接头）Polyethylenetapes（聚乙烯胶带）ShrinksleevesPolypropyleneMechanicalprotectionPolyethylenecoatings:3layers(PE3L),Functionsoftheanticorrosioncoating,Coatingsforpipelines,Fieldjointcoatings(weldedjoints),Componentsofinsulatedpipeline,Complementarymechanicalprotection,Theseprotectionsareusedcomplementarytotheanti-corrosivecoating:-inrockground,-whenconcretesaddlearenecessaryThemechanicalprotectionshavetosatisfytoparticulartests:-indentationandimpact,-absorptivityinaqueousenvironment,-resistancetotheattackbymicro-organisms,Complementarymechanicalprotection,FusionBondedEpoxy(FBE)Field,FBEcoatingshavebeeninuseforundergroundandunderseapipelineprotectionfornearlyfortyyears.,AsignificantadvantageofFBEcoatingsystemsisthatthesamematerialscanbeusedonthegirthweldasontherestofthepipe,Three-layerpolyolefin（聚烯烃）coatingsystemsutilizeFBEastheprimarycorrosionbarrier.,FBEinternalpipecoatingsprovidecorrosionprotectionaswellasimprovedfluidflow.,FusionBondedEpoxy(FBE)FieldJointCoating,2.mechanismsandcharacteristicsofvariouscoatings,a.SacrificialcoatingsZinc-richprimersareappliedat3.0-mildry-filmthicknesstoprovidegalvanicprotection.thezincwilldissipatebeforethesteelisattacked.Adequatehigh-performancetopcoatsarerecommendedtoprolongthelifeofthecoating.,-mil密尔（千分之一英寸）Zinc-richprimers富锌底漆,b.Corrosioninhibitors,Mostpaintprimerscontainapartiallysolubleinhibitorpigment,e.g.,zincchromate,thatreactswiththesteelsubstratetoformtheironsalt,Suchsaltslowsdowncorrosion.Chromates,phosphates,molybdates,borates,silicatesandplumbatesarecommonlyused.,zincchromate:铬酸锌phosphates磷酸盐；molybdate钼酸盐；borates硼酸盐；silicates硅酸盐；plumbate高铝酸盐；alkalinity碱性,c.Barriercoatings,Protectivecoatingsarethemostwidelyusedandrecognizedformsofbarriermaterial.Barriercoatingsareeffectivebecausetheykeepmoistureandoxygenawayfromthesteelsubstrate.,barriercoating防护涂层；bricklinings砖衬里barriermaterial阻隔材料,4.Implementationofthecoatingonsite,Implementationofacoatingonfieldjoint(welding),Coatingofasupport,Implementationofthecoatingonline,Coatingcontrolwith