分馏塔YW.docx

分馏塔YW.docx

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分馏塔YW

Contents

1Projectoutline

1.1Applicablescope

Thisschemewillapplytotheassembly,andinstallationofthecokingdistillationtower（φ4400×56569×（3+16）/（3+18））fortheprojectofKhartoumoilRefineryextension,thematerialofthetowershellis316L+20R

1.2Projectcharacteristics

1.2.1Highweldingqualityrequirementandhighflawdetectionratio.Duetodifficulttransportation,thetowerwillbeprefabricatedinpiecesandtransportedtositeforassemblyanderection

1.2.2Deliverystateofthetower

1.2.2.1Thetowershellwillbedeliveredin52pieces,including8shirtpiecesand2pieceseachsectionwhicharerolledinaccordantwiththeO.D.oftheheadsandmarkedwiththeirnumberinthedrawingsandbeveledforwelding

1.2.2.2ExternalnozzleswillbeweldedwithflangesandNOTinspectedandidentifiedwithmarksindrawings（reinforcementpadswillrolledinshapeandbeveled）.

1.2.2.3Theskirtpartsandsupportingringsfortraysandinsulationlayerswillbepre-fabricatedandmarkedinaccordancewithdrawings

1.2.2.4Thetraysandinternalswillbeprovidedinformofproducts

1.2.2.5Thetopandbottomheadswillbeprovidedwithmachinebevelsandopeningsmadewithbevelsinaccordancewiththedrawing.

1.3Preparationbasis

1.3.1Theequipmentdesigndrawings（2003-522P1-75）

1.3.2《Steelpressurevessels》（GB150-98）

1.3.3《Safetysupervisionprocedureforpressurevessels》

1.3.6《Codeforconstructionandacceptanceoflowandmediumpressurechemicalindustryequipment》（HGJ209-83）

1.3.7《Codeforconstructionandacceptanceofchemicaltowertypeequipment》（HGJ211-85）

1.3.8《NDTofPressurevessels》（JB4730-94）

1.3.9《Codeforconstructionandacceptanceofsiteequipment,industrypipingweldingproject》（GB50236-98）

2.Constructionprocedure

Theassemblymethodofthedistillationtower:

（1）Weldingeachcourseoftheshell.

（2）AssemblingintofoursectionsaccordingtotheFigare.1

（3）Liftingtheskirtinplaceanderectingit.

（4）OverheadAssemblyofsectionsonsiteandmakingalignment

Thesequenceinasfollows:

technicalpreparationpriortoconstructionandfoundationacceptance→acceptanceofmaterialreceivedatsite→weldingeachcourseoftheshell→Assemblinginto4sections→openingandnozzlemakingineachsection→wildlytrayandinsulationsupportingrings→installationofladdersandplatformsineachsection→puttingskirt（sectionone）inplaceandalignment→erectionthesectiontwo、threeandfour.

Figure1

3.Mainconstructionmethod.

3.1Preparationpriortoassembly.

3.1.1Preparationofclean,flatandcompactedgroundwithenoughareaforpavementoftheplatformplates,gettingreadytheassemblytools,acceptanceofthetowerfoundationandpreparationofironblocksforinstallation.

3.1.2Transportationoftheprefabricatedpiecestothesiteandinspectionacceptanceofmaterialsbysupplyingdepartmentinaccordancewiththespecifiedstandardsandcontractterms.

3.1.3Preparationofscaffoldingswethershedsandclampingtoolsforassembly.

3.1.4EstablishmentoftheQAsystemforassemblingandweldingpressurevesselsonsiteandpreparationofWPScards.

3.1.5Preparationofqualityandworkingstepcontrolproceduresanddeterminationofresponsiblepersonforwordingstepcontrol.

3.2Assemblyandalignmentofcoursesofthetowershell.

3.2.1Layingoffontheassemblyplatform,markingacirclewithshelldiameterof4400mm,liftingtheprefabricatedpiecesandputtingthemuprightalongthecircle,adjustingtheirbottomendswithUpiecesandwedgessothattheirinsidesconsistentwiththecircle

3.2.2Levelingthebottomendswithsmallflatbarsorinclinedironandinspectionwithlevels.

3.2.3Welding3or4“日”piecesalongaverticaljointonitsbothsideshammeringthewedgestomakealignmentbetweentwopiecesothattheoffsetwithinthetolerance.

3.2.4Adjustmentofthecourseoftheshell,includingant-of-roundness,outsidecircumferenceleveloftopandbottomrimssothattheparametersmeetthespecifiedrequirements.Thelinearitydeviationinany3mlengthofshellshallbecontrolledwithin3mm.Themethodforadjustmentofout-of-roundnessinshowontheFigure2.

Figure2

3.2.5Tacklingtheverticaljointswithtackingweldsof30-50mm,andthenweldinginlayers.

3.3AssemblyofandAlignmentbetweencoarsestofashellsection

3.3.1Coursesofashellsectionwillbeerectedfrombottomtotop.Thetoleranceforalignmentandassemblyofsectionsisshownonshownonthetable-1.

Toleranceforparameters（table-1）unit：

mm

Outofroundness

Outoflevelfortopendofeachcourseofshell

Outsidecircumference

Offset

Sharpness

Outofplumb

≯25

≯2

±18

≤10%S

≤10%S+2

45

S——shellwallthickness

3.3.2AccordingtotheFigure-1assemblingandweldingoftheshirt（course4）andthetowerbaseplate;levelingthebottomedgesoftheskirt（course4）,course5,11and21;determinationofthelocationsof0°、90°、180°and270°andmarkingthemwithredanglesinsuchawaythatthetheodolitecanbeusedtomeasuretheassemblydeviationinstraightness.

3.3.3Considerationstallbemadesothatnozzleopeningswillnotbelocatedatthewelds.Forthis,thecoursesofshelltobeassembledstallbeorientationadjustedonthesiteandmarkedindirectionof0°、90°、180°and270°.

3.3.4Liftingthecourseofshelltobeerected,puttingitinplaceandmakingalignmentasshowninFigure3.Foralignment,thelimitpiecesshallbeset.

Figure3

3.3.5Locating4adjustingthreadingbarsofφ48evenlyalongthegirthjointtoadjustthegat.Thetheodolitewillbeusedforplumbadjustment.Thecontrolofdeviationfromstraightnesswillbecarriedoutusingthefollowingmethod;wiresofφ0.5mmwillbesetinlocationof0°、90°、180°and270°andmeasurementtheinspecifiedpointstocontrolthestraightnessdeviationwithinthetolerance.

3.3.6Erectionofcoursesofashellsectionfrombottomtotopandmakingnecessaryadjustmentsothattheparameterstobecontrolledmeetthetolerancerequirements.

3.4Installationofnozzles

3.4.1Requirementfornozzles

3.4.1.1Theboltholesofflangesshallstraddlethecenterlinesevenly.

3.4.1.2Thesealfacesofflangesshallbeperpendicularorparallelwiththeshellaxis,andthedeviationstallbewithin1%ofO.Dand3mmasmaximum.

3.4.1.3Thenozzlesforalevelglassstallbeinstalledinsuchawaythatthedistancebetweentwonozzlesmeetthetoleranceof±1.5mmandtheirlocationdeviationincirculardirectionshallbewithin1mmandtheinclinationoftheflangefacestallnotbeover0.3mm.

3.4.1.4ForopeningsintheshellortheskirtwithdiameterofDN500ormore,reinforcementpadswiththicknessofδ16andanglesof∠50×5shallbeused.

3.4.2Theordinationandelevationofeachnozzleopeningshallbedeterminedcarefullyinthecorrespondingshellsectionandconfirmedbyequipmentandprocesstechnicianstogetherwithqualityinspectorandforeman.Thecut-outshallnotbecarriedoutuntiltheA.Mlocationconfirmationiscompleted.

3.4.3Considerationshallbemadesothatopeningswillnotbelocatedonwelds.forthis,necessaryorientationadjustmentofshellcourseshallbemadeonsite.

3.4.4Reinforcementpads:

Seeweldingprocedurerequirementforbevelandgapdetails.Thegapbetweenare-padandtheshellshallbelessthan1mmandscrewholeshallbelocatedatthepadbottom.

3.5Erectionofshellsectionsandassemblyofsupportingrings.

3.5.1Attentionshallbepaidtotheelevationsandtheorientationsofsupportingringsandtheirlocationsshallbecarefullydeterminedinthecorrespondingshallsections.

3.5.2Aftertraysupportingringsareweldedontheinsidewalloftheshell,thelocalleveldeviationoftheirtopsurfacesin300mmchordshallnotbeover1mm,theleveldeviationofawholeringtopsurfaceshallnotbeover6mm.Thedistancedifferencebetweentwosameadjacentringsshallbewithin±3mm.Thedistancedifferencebetweentwodifferentadjacentringsshallbewithin±10mmevery20lagersofrings.

3.5.3Thedistancedifferencebetweendowncomerbottomendandtopsurfaceofthecorrespondingsealpanshallbewithin±3mm,thehorizontaldistancedifferencebetweendowncomerandstandingedgeofthecorrespondingsealpanshallbewithinthescopefrom-3to5mm.Thedistancedifferencefromdowncomerthroughcentertoshellinsidewallshallbewithin±6mm.Thetoleranceformediatedowncomerdistanceshallbe±6mm.

3.5.4Theweldingslagsandspattersshallberemovedfrominsideandoutsidesurfacesofthevessel.

3.6Installationofplatformsandladdersoneachshallsection.

3.6.1Inordertoreducetheoverheadwork,laddersandplatformsshallbeinstalledtothecorrespondingshellsectionsontheground.Attentionshallbepaidtotheirelevationandorientationtoensurecorrectlocation.

3.6.2Whenladdersaresetinplace,thesecuredconnectionsofthemtoplatformsandpostsshallbemade,ifnecessaryreinforcementanglesshallbeused.

3.6.3Whenrailingsareerected,attentionshallbepaidtotheirverticalityelevationanddistanceandsmoothtransitionshallbemadeatcorners.

3.6.4Laddersshallbefirmlyconnectedtoplatformsandposts.

3.6.5Aftercompletionofinstallation,weldingslagsandburrsshallberemovedandadimensioninspectionshallbemadesothattherequirementsinthefollowingtablearemet.

ToleranceforInstallationofPlatforms、laddersandrailings（Table-2）unit:

mm

ItemNo.

description

tolerance

remark

1

Lengthandwidthofplatform

±4

2

Diagonaldifference

6.0

3

Outofflatnessforplatformsurface

3.0

4

Warpofladderinlongitudinaldirection

≤Lt/1000

Lt—overalllengthofladder

5

Outofflatnessfortradeplatesofs