城市热力管道施工

城市热力管道施工

Inthehighschool

Constructionof2K315020urbanthermalpipeline

Constructionof2k315020urbanthermalpipeline

2k315021masterurbanthermalpipelineconstruction

requirements

Engineeringsurvey

Pipelinesurveyshouldbeconsistentwith:

Itshouldbecarriedoutaccordingtothemainline,branch1ine

andbranchline.

Inthepipeline,fixedbracket,buildingontheground,

examinationroom,compensator,valvesinthepipelinelocation,

measurewithrulerpositionmethod.

Two.Civilengineering

Theexcavationoftheearthmustbebasedontheprovisionsof

therelevantprovisionsofthegrooveedgeguardrail,night

lightsandredlightsandotherfacilities,andtheneedtoset

temporaryroadsandbridges.

Three,welding

2.buttjointswithunequalwal1thicknessshallcomplywith

thefollowingprovisions:

(1)whentheouterdiameterisequalortheinnerdiameteris

equal,thethicknessofthethinpieceislessthanorequal

to4mm,thethicknessdifferenceisgreaterthan3mm,andthe

thicknessofthethinpartisgreaterthan4mm,andthe

thicknessdifferenceisgreaterthan30%ormorethanthe

thicknessofthethinpart,thethickpartshouldbethinned.

(2)theinnerdiameterandouterdiameterareunequal,andthe

thicknessdifferenceofonesideexceedsthevaluelistedin

the1paragraphofthisarticle,thethicknessofoneendof

thepipewallshouldbethinned,andthethicknessofthe

interfaceafterthethinningshouldbeuniform.

4.whenweldingbelowzero,preheatingofweldmentshouldbe

carriedoutintherangeof50mmonbothsidesoftheweld.

6.unqualifiedweldingparts,measuresshouldbetakento

repair,thesamesiteweldingrepairfrequencyshallnotexceed

2times.

Four.Pipinginstallationandinspection

3.buttjointshouldcomplywiththeprovisions

1.whenthebuttjointisopened,thestraightnessofthepipe

shallbecheckedandmeasuredat200mmfromthecenterofthe

interface.TheallowabledeviationisLMM,andthemaximum

deviationshallnotexceed10mminthefulllengthrangeofthe

buttweldedsteelpipe;

4.flangeconnectionshouldcomplywiththeprovisions

(4)whenlargediametergasketsneedtobespliced,thebutt

jointorlabyrinthjointshouldbeused,andthebuttjoint

shouldnotbeweldedlongitudinally.Thegasketsizeshouldbe

equaltotheflangesealingsurface.

(9)whentheflangeandaccessoriesareassembled,the

allowabledeviationofverticalityis2〜3mm

(five)valveinstallationshouldcomplywiththeprovisions

4,whenthevalveandpipewithflangeorthreadconnection,

thevalveshouldbeinstalledintheclosedstate;whenthe

valveandthepipelineweldedconnection,thevalvemustnot

beclosed.

7,valvetransportHoistingisnottousethevalvehandwheel

ashoistingloadpoints.

9.weldingbutterflyvalve

(1)theaxisofthevalveplateshouldbeinstalledinthe

horizontaldirection,themaximumanglebetweentheshaftand

thehorizontalplaneshouldnotbegreaterthan60degrees,it

isstrictlyprohibitedtoinstallvertically.

(2)wheninstallingtheriser,thewaterabove100mmshouldbe

injectedintotheclosedvalveplatebeforewelding.

(3)afterwelding,2or3timesofcompleteopeningtoprove

whetherthevalvecanworkproperly.

Seven.Thermalinsulationproject

1.whenthethicknessofinsulationlayerismorethan100mm,

itshouldbedividedintotwolayersorlayersbylayer

construction

2,tiletypeinsulationproductgapwidthnotgreaterthan5mm.

ThegapwithasbestoscementandAshFilledmasonrytightpad

internalwipeasbestosdustclaylayerwiththethicknessof

3〜5nim,andtheconstructionshouldbestaggered.Whenmorethan

2layersofthermalinsulationproducts,thesamelayershould

bewrongseam,insideandoutsidethelayershouldbepressure

seam,itslaplengthshouldnotbelessthan50mm.Eachtile

shouldbetwogalvanizedsteelwireorbandtiedwithspiral

bindingmethodsshallbe.

5.theendofthepipelineortherightblindplateshouldbe

laidinsulationlayer.

Eight.Pressuretest,cleaningandtestrun

1.strengthtestandtightnesstestshouldbecarriedoutfor

twoprimarypipenetworkandtwogradepipenetwork.The

strengthtestpressureshouldbe1.5timesthedesignpressure,

thetightnesstestpressureshouldbe1.25timesthedesign

pressure,andshallnotbelessthan0.6mpa.

Thetestofpipingandequipmentinthe2.thermalpowerstation

andtherelaypumpstationshallcomplywiththefollowing

provisions:

(1)allthesystemsinthestationshouldbetestedstrictly,

thetestpressureshouldbe1.25timesthedesignpressure,and

shal1notbelessthan0.6mpa.

(3)theopentypeequipmentisonlyusedforfullwatertest,

withnoleakageasqualified.

3.heatingnetworkcleaningshouldbecarriedoutbeforethe

trialoperation.

4.cleaningmethodscanbedividedintomanualcleaning,

hydraulicflushingandgasblowing.

8.commissioningshouldmeetthefollowingrequirements:

(4)thetrialruntimeshouldstartfromthenormaltestrun

timeof72h.

(5)theheatingprojectshouldbetestedundertheparameters

approvedbytheconstructionunitandthedesignunit,andthe

testruntimeshouldbecontinuousoperation72h.Thetestrun

shouldbeslowlyheatingup,andtheheatingrateshouldnot

begreaterthan10C/h.

Eight,completionacceptance

1.engineeringqualityacceptanceisdividedinto"qualified”

and“unqualified"”.Unqualified,notacceptance,untilrework,

reworkqualified.

2.thequalityacceptanceoftheprojectshallbedividedinto

subitems,subdivisionsandunits.

3.acceptanceassessmentshallmeetthefollowing

requirements:

(1)thesubprojectconformstothefollowingtworequirements,

whichisqualified:

Themaincontrolprogram(1)listedinthediscussionitem)

qualifiedrateshouldreach100%.

2)thequalifiedrateofgeneralitemsshouldnotbelessthan

80%,andthepointsthatdonotmeettherequirementsofthe

code,themaximumdeviationshouldbewithin1.5timesthe

allowabledeviation.

(2)subprojectqualificationmustbequalifiedforallsub

projects

(3)qualifiedunitsmustbequalifiedforallsubprojects

2K315022isfamiliarwiththeclassificationandmain

accessoriesofurbanheatpipenetwork

2k315022isfamiliarwiththeclassificationandmain

accessoriesofurbanheatpipenetwork

First,thetypesofheatpipenetwork

(1)accordingtoheatmediumtype

Lsteamheatingnetwork

2.hotwaterheatingnetwork

Lowtemperaturehotwaterheatingsystem(2):T=95C.

(two)accordingtotheposition

1.levelonepipenetwork:fromtheheatsourcetotheheat

stationofthewatersupplyandreturnnetwork;

2.twolevelpipenetwork:fromheatstationtouser'swater

supplyandreturnpipenetwork.

(three)accordingtolayingway

1.trenchlayingcanbedividedinto:trench,semipass,non

passtrench;

2.overheadlayingcanbedividedinto:highbracket,middle

bracket,lowbracket;

3.directlyburiedlaying:thepipelineisdirectlyburiedin

theunderground,nopipeditch.

(four)accordingtothesystemform

1.closedsystem:theprimaryheatsupplynetworkandthetwo

heatsupplynetworkareconnectedbytheheatexchanger.The

heatmediumlossoftheprimaryheatsupplynetworkisvery

smal1,buttheintermediateequipmentismore,andthe

practicaluseismoreextensive;

2.opensystem:directconsumptionofheatmedium,few

intermediateequipment,butalargeamountofheatmedia

supplement.

(five)accordingtotheclassificationofsupplyandreturn

1.watersupplypipe(steamsupplypipenetwork:):fromtheheat

sourcetoheattheuser(orheatstation)pipeline;

2.returnpipe(steamnetwork:condensatepipe):heatfromthe

user(orheatstation)backtotheheatpipe.

Two.Mainaccessoriesofheatpipenetwork

Themainaccessoriesofheatpipenetworkarecompensator,

hanger,valveandsoon.

2k315031mastertheinstallationrequirementsofcitygas

pipeline

First,materialselectionofgaspipeline

Highpressureandmediumpressureagaspipelineshouldadopt

steelpipe;mediumpressureBandlowpressuregaspipeline;

steelpipeormechanicalinterfacecastironpipeshouldbe

adopted.Polyethylenepipesareusedinmediumandlowpressure

pipes.

Two.Installationofindoorgaspipeline

1.intheplacewherepeoplewalk,thelayingheightshouldnot

belessthan2.2m

2.theheightshal1notbelessthan4.5mintheplacewhere

thevehicleisavailable

Gasapplianceandgaspipelineshouldadoptthepipeconnection,

connectedbyahose,thehoselengthshouldnotexceed2m,have

nointerface,usedintheproductionofmobilegasequipment

shal1betheconnectinghoseshouldnotexceed30m,the

interfaceisnotmorethan2.

Three.Installationofoutdoorgaspipeline

(1)basicrequirementsforpipelineinstallation

One

Undergroundgaspipelinesshallnotpassthroughbuildingsand

largestructures.

2.theminimumcoverthicknessofburiedgaspipeline(pavement

topipetop)shallmeetthefollowingrequirements:

Buriedintheunderground,notlessthan0.9m;buriedinnon

roadwayisnotlessthan0.6m;buriedinthecourtyard,notless

than0.3m;buriedinthepaddyfieldisnotlessthan0.8m

3.theundergroundgaspipelineshallnotbecrossedunderthe

siteofaccumulationofflammableandexplosivematerialsand

corrosiveliquid,andshallnotbelaidinthesameditchas

otherpipelinesorcables.

4.whentheundergroundgaspipelinepassesthroughthedrain

pipe,theheatpipeditch,thecombinedtrench,thetunneland

othervarioususegrooves,thegaspipelineshouldbelaidin

thecasing.

The5.gaspipelineshouldmeetthefollowingrequirementswhen

crossingtheraiIway,expressway,tramtrackandmainurban

roads:

(1)thegaspipelinepassingthroughtherailwayandthe

expresswayshouldbeconnectedwiththecasing.Thecasingof

thegaspipelinecrossingtherailwayshouldmeetthefollowing

requirements:

1)thedepthofcasingEmbedment:therailtracktothetopof

thecasingshouldnotbelessthan1.20m,andshouldcomplywith

therequirementsoftherailwayadministrationdepartment;

2)thecasingshallbemadeofsteelpipeorreinforcedconcrete

pipe;

3)theinnerdiameterofthecasingshouldbemorethan100mm

largerthantheouterdiameterofthegaspipeline;

4)thegapbetweenthetwoendsofthecasingandthegaspipe

shouldbemadeofflexibleanti-corrosionandwaterproof

material,andoneoftheendsshouldbeequippedwithaleak

detector;

5)theendofthecasingdistancefromtheembankmentangle

shouldnotbelessthan2.om.

(3)gaspipelinecrossingtramrailandurbanmainroadsshould

belaidinthecasingortrench;gaspipelinecasing,Gas

PipelineCrossingExpresswayacrossthemainroadofthetown

carandthecasingortrench,shouldmeetthefollowing

requirements:

1)theinnerdiameterofthecasingshouldbegreaterthan100mm

oftheouterdiameterofthegaspipeline,andtheendsofthe

casingortrenchshouldbesealed,andtheleakdetectorpipe

shouldbeinstalledattheendofthecasingortheendofthe

trenchintheimportantarea.

2)thedistancebetweentheendsofthecasingandtheelectric

laneshouldnotbelessthan2.om,andthedistancefromthe

edgeoftheroadshouldnotbelessthan1.om.

3)gaspipelineshouldbeperpendiculartorailway,expressway,

tramtrackandmaintrunkroadsofcitiesandtowns.

(two)basicrequirementsforpipelineembedment

1.whentheartificialexcavationandnogroundwaterareused

inthetrenchexcavation,thereservedvalueofthebottomof

thetrenchshouldbe0.05~0.Im.Whenthemechanicalexcavation

andgroundwaterareused,thereservedvalueofthebottomof

thetrenchisnotlessthan0.15m.

Backfill.Whentheditchwithoutgroundwater,overbreaking

within0.15mwithoriginalsoilbackfill,overbreakin0.15m

andabovebylimesoi1treatment,whenditchalargeamountof

waterorgroundwater,thegradedgravelbackfilltothe

elevation.

2.backfillsoil

Backfillshouldbestratifiedcompaction,eachlayerthickness

shouldbe0.2〜0.3m,onbothsidesofthepipelineand0.5mabove

thetopofpipeinthebackfillmustadoptartificialbackfill

compaction,thetopofthepipeabove0.5mcanbeusedforsmall

mechanicalcompaction,eachlayerthicknessshouldbe

0.25〜0.4m.

3,warningbeltlaying

Thewarningbeltshouldbecontinuouslylaidalongtheburied

gaspipeline.Beforethelayingofthewarningbelt,thelaying

surfaceshouldbecompactedandlaidonthetopofthepipeline.

Thedistancefromthetopofthepipeshouldbe0.3~0.5m,but

itshouldnotbelaidontheroadbedandroadsurface.

Thewarningtapeisyellowpolyethylenematerial.

Four.Testmethodofgaspipeline

Afterthepipelineisinstalled,thepipelinepurging,strength

testandtightnesstestshouldbecarriedoutinturn.

(1)purgingofpipes

1.gaspurgingshouldbeselectedaccordingtothefollowing

requirements:

(1)ductileironpipe,polyethylenepipe,steelskeleton

polyethylenecompositepipeandsteelpipewithnominal

diameterlessthan100mmorlengthlessthanloom,canbeblown

bygas.

(2)thesteelpipewithnominaldiametergreaterthanorequal

to100mmshouldbecleanedbypiggingball.

2.pipingpurgingshallcomplywiththefollowingrequirements:

Blowingintheorderofthemainpipe,branchpipeandcourtyard

pipe,andthedirtsweepingawayshallnotenterthequalified

pipeline.

Thepressureregulator,valve,orificeplate,filterscreen,

gasmeterandotherequipmentinthepurgingpipesectionshall

notbeinvolvedinpurging,andthenresetafterpurging.

Thepurgepressureshallnotbegreaterthanthedesignpressure

ofthepiping,andshallnotbegreaterthan0.3mpa.

Purgemediashouldbecompressedair,oxygenandflammable

gasesareprohibited.

3.gaspurgingshouldcomplywiththefollowingrequirements:

(3)thelengthofeachpurgingpipeshouldnotexceed500m;when

thepipelengthismorethan500m,itshouldbeswept

separately.

(5)whenthereisnosmokeanddustinthevisualinspection,

thewhiteclothorwhitecoatedwoodtargetplateshouldbeset

attheexhaustport,andthetargetofnorust,dustandother

impuritiesinthe5minisqualified.

4.piggingbal1cleaningshouldmeetthefollowing

requirements:

(1)thediameterofthepipelinemustbeofthesamesize,and

thepipeswithdifferentdiametersshouldbedisconnectedand

cleanedseparately.

(two)strengthtest

Undernormalcircumstances,thetestpressureis1.5times

higherthanthedesignedgaspressure,butthesteelpipeshall

notbelessthan0.4MPa,polyethylenepipe(sdrll)shal1not

belessthan0.4MPa,polyethylenepipe(sdrl7.6)shallnotbe

lessthan0.2mpa.Whenthepressurereachesthespecifiedvalue,

the1Hshouldberegulated,andthenthepipelineinterfacecan

becheckedwithsoapandwater.Alltheinterfacesarefreeof

airleakage,andtheyareconsideredqualified.Ifthereisa

leak,itcanberepairedafterbeingdeflated,andthentested

againaftertherepair,untilqualified.

(three)tightnesstest

Thetightnesstestshouldbecarriedoutafterthestrengthtest

isqualifiedandthepipelineisbackfilledalloverthe

pipeline.Tightnesstestpressuredependsonthedesignofgas

transmissionpipelinedesignpressure,whenthegaspressure

ofPwaslessthan5kpa,thetestpressureis20KPa;whenpis

largerthan5kpa,thetestpressureshallbe1.15timesthe

designpressure,butnotlessthan0.Impa.Beforethetightness

test,thepipelineshouldbeinflatedtothetestpressure,the

tightnesstestdurationofgaspipelineisgenerallynotless

than24h,theactualpressuredropisnotmorethanthe

allowablevalueisqualified.

2K315032isfamiliarwiththeclassificationandmain

accessoriesofcitygaspipeline

2k315032isfamiliarwiththeclassificationandmain

accessoriesofcitygaspipeline

Thetypesofgaspipeline

(1)gasclassification

Therearemainlyartificialgas(gas),naturalgasand

liquefiedpetroleumgas.

(two)classificationofgaspipelines

1.classificationbyuse

(1)longdistancegaspipeline

(2)citygaspipeline

(3)gaspipelinesinindustrialenterprises

2.classificationaccordingtolayingmethod

(1)undergroundgaspipeline:undergroundlayingisusually

usedincities.

(2)overheadgaspipeline:inthepipelinethroughobstacles,

orinthefactoryareainordertomanageandmaintain

convenience,overheadlaying.

3.classificationaccordingtogastransmissionpressure

Accordingtothegastransmissionpressure,thecitygas

pipelineinourcountryisgenerallydividedintotwoparts:

(1)lowpressuregaspipeline:

(2)mediumpressureBgaspipeline:

(3)mediumpressureagaspipeline:

(4)subhighpressureBgaspipeline:

(5)subhighpressureagaspipeline:

(6)highpressureBgaspipeline:

(7)highpressureagaspipeline:

MVBAandmediumpressurepipingmustbethroughtheregional

subscriberstationtostation,citydistributionnetworkinthe

lowandmediumpressuregaspipeline,ortofactoriesand

enterprises,usersoflargepublicbuildingsandgasboiler

room.

Generally,theurbanhighpressureBgaspipelineconstitutes

theouterringnetworkofthelargecitypipelinesystem.High

pressureBgaspipelinesarealsotheaortathatsuppliesgas

tobigcities.

Highpressureapipelineisalongdistancepipelinethatruns

throughprovinces,regionsorconnectingcities.Itsometimes

constitutestheouterringnetworkoflargeurbanpipeline

network.

Two.Gaspipelineancillaryfacilities

Inordertoensurethesafeoperationofthepipenetwork,

Consideringtheneedofmaintenanceandwiring,thenecessary

accessoryequipmentissetupintheproperplaceofthe

pipeline.Thesedevicesincludevalves,compensators,drains,

drainpipes,etc..

(1)valves

Valveisusedtoopenandclosethepipelineaccessoradjust

thepipelinemediumflowequipment.Thetightnesstestshould

bedonebeforeinstallation,theleakageisnotqualified,and

theunqualifiedpersonshouldnotbeinstalled.

Valveinstallationshouldpayattentiontotheproblem:

1.directivity

2.installationposition

3.otherproblemsshouldbepaidattentionto

(two)compensator

Asadevicetoeliminatethestressofexpansionandcontraction

inthepipesection,thecompensatoriscommonlyusedin

overheadpipelinesandpipelineswhichneedsteampurging.The

compensatorisusuallyinstalledonthelowersideofthevalve

(inthedirectionofairflow),anditstelescopicperformance

isusedtofacilitatethedisassemblyandmaintenanceofthe

valve.Intheburiedgaspipeline,thesteelwavecompensator

isusedmoreoften,