空调铜管施工方案

ConstructionPlanforAirConditionerCopperPipe空调铜管施工方案Generals工程概况Thisprojectcomprisesroofairconditioningunit,indoorbuilt-uptypeairconditioningbox,andconnectionofcopperpipelineintwoequipmentrooms.Thesiteconstructionofcopperpipeisthemainqualitypointofconstruction.本工程包括屋顶空调机组，室内组合式空调箱及两设备间的铜管管线的连接。其中现场铜管施工为本程的施工质量重点。二、Copperpipeselection铜管的选择CategoryStandardouterdiameter（allowabledeviation）DOmmWallthickness（allowabledeviation）tmmMax.operatingpressure最高使用压力PMPaAllowabletensilestress充许拉伸应力oaN/mm2OandOL19.05(±0.03)1.00(±0.09)3.61633(Temperatureat125℃的)allowabletensilestress）22.22(±0.03)1.15(±0.09)3.56328.58(±0.04)1.45(±0.10)3.49类别标准外径（允许差）DOmm壁厚（允许差）tmm最高使用压力PMPa充许拉伸应力oaN/mm2O及OL19.05(±0.03)1.00(±0.09)3.61633(温度在125℃的)充许拉伸应力）22.22(±0.03)1.15(±0.09)3.56328.58(±0.04)1.45(±0.10)3.49CategoryStandardouterdiameter(allowabledeviation）DOmmWallthickness（allowabledeviation）tmmMax.operatingpressurePMPaAllowabletensilestressoaN/mm21/2HorH19.05(±0.03)1.00(±0.09)6.68461(Temperatureat125℃)allowabletensilestress）22.22(±0.03)1.00(±0.09)5.69428.58(±0.04)1.00(±0.09)4.391类别标准外径（允许差）DOmm壁厚（允许差）tmm最高使用压力PMPa充许拉伸应力oaN/mm21/2H或者H19.05(±0.03)1.00(±0.09)6.68461(温度在125℃的)充许拉伸应力）22.22(±0.03)1.00(±0.09)5.69428.58(±0.04)1.00(±0.09)4.391Categoryoftubingisdistinguishedbymaximumoperatingpressure(designpressure),accordingtodrawingdesignedandconstructionspecification,refrigeratingfluidshalluseR407Corequivalentotherrefrigerant.R407Cdesignpressureisgenerallyabout3.45MPa,R410Adesignpressureisgenerallyabout4.15MPa.配管的类别根据最高使用压力(设计压力)来区分的，根据图纸设计及施工说明，制冷剂采用R407C或相近的其它环保冷媒。使用R407C设计压力一般为3.45MPa左右，R410A的设计压力一般为4.15MPa左右。5Computationformulaofwallthickness壁厚的计算公式Thecomputationformulaofthecompulsorycopperpipe(TP2M)thicknessisasfollows.铜管(TP2M)必须厚度的计算公式、如下。ｔ=[(Ｐ×OD)／(2σa+0.8P)]+α(㎜)

ｔ：compulsorywallthickness必须的壁厚(㎜)

P：max.operatingpressure(designpressure)最高使用的压力(设计压力)(MPa)

OD：standardouterdiameter标准外径(㎜)

σa：min.allowablestressattemperature125℃在125℃的基本许可应力(N／㎜2)

＊σa=33(N／㎜2)

α：Corrosionthickness(mm)＊but,forcopperpipe,itshallbe0(mm).腐蚀厚度(㎜)

＊但是，对铜管的话为0(㎜)。Exampleofdesignselection（TP2M）:thefollowingtakesO-type(TP2M)copperpipedesignasexample设计选择示例（TP2M）:以下以O型（TP2M）铜管设计为例WallthicknessselectionofR407Crefrigeratingsystemexhaustpipeset,itisassumedthattheouterdiameterofexhaustpipesetisφ19.05,thewallthicknessselectionmethodshallbeasfollows:R407C制冷系统排气管组壁厚选择，假设排气管组外径φ19.05，其壁厚选择方法如下：MaximumpressureofR407Crefrigeratingsystematexhaustairsidetakes3.45MPa,calculationisasfollows:R407C制冷系统排气侧最高压力取3.45MPa，计算如下：Wallthickness壁厚ｔ=[(P×OD)／(2σa+0.8P)]+α(㎜)

=（3.45×19.05）/（2×33+0.8×3.45）+0=0.9558mmTakingroundnumber取整，t=1.0mm。Note:φ19.05copperpipewallthicknessdeviationclassVspecifiedinGB/T1804maybe±0.08mm,inthisway,ifsupplierusescopperpipewithwallthicknessdeviationof-0.08mmtoproducepipesetinordertoeconomizecost,itswallthicknessshallselect0.29mm.wecangettoknowfromthecalculationresult,whendesignpressureofthepipesetis3.45MPa,pipecrackingmayhappen.Atthistime,wemustaddcopperpipewallthicknesstoensurethepipesetnotcracked,ortoexplicitlystipulateinthetechnicalrequirementthepipesetwallthicknesswithinsuitabledeviation,i.e.deviationrangeat（-0.4，+0.08）mm,toavoidthepipesetfromcracking.注：国标GB/T1804规定φ19.05的铜管壁厚V级偏差可以是±0.08mm，这样如果供货厂家为节省成本，采用壁厚偏差-0.08mm来生产管组，则其壁厚就会选取为0.92mm了，这样由计算结果可知，该管组在设计压力为3.45MPa时，就会有裂管的隐患了。这时必须通过适当增加铜管壁厚来保证该管组不会爆裂，或者在技术要求中明确规定管组壁厚在适当的偏差内，即偏差范围在（-0.4，+0.08）mm内，以免除管组爆裂隐患。②R410AWallthicknessselectionofrefrigeratingsystemexhaustpipeset,itisassumedthattheouterdiameterofexhaustpipeisφ19.05,thewallthicknessselectionmethodisasfollows:制冷系统排气管组壁厚选择，假设排气管组外径φ19.05，其壁厚选择方法如下：R410Arefrigeratingsystemmax.pressureathighpressuresideisdesignedas4.15MPa,itswallthicknesscalculationisasfollows:R410A制冷系统高压侧最高压力设计为4.15MPa，则其壁厚计算为：Wallthickness壁厚ｔ=[(Ｐ×OD)／(2σa+0.8P)]+α(㎜)=（4.15×19.05）/（2×33+0.8×4.15）+0=1.14mmTakeroundnumbert=1.2mm,suchwallthicknesscanalsomeetdesignrequirementaccordingtoGB/T1804.Ifthepipesetdoesnotneedfolding,selectO-typepipewithwallthicknessof1.2mm,thecostisincreasedby20%tobecomparewithH/2pipewithwallthicknessof1.0mm.Suchdesignisuneconomical.Whereas,accordingtotable2,wemaygettoknowthatwhenweuseH/2(TP2Y)copperpipe,thewallthicknessis1.0mm,itsresistancetopressurecanreach6.684MPa,fullyconformingtothedesignpressurerequired.Therefore,undersuchacircumstance,weshouldselectH/2(TP2Y)copperpipewithwallthicknessof1.0mm.进行取整t=1.2mm,此壁厚按照国标GB/T1804规定V级偏差也能满足设计要求。如果该管组不需要折弯，选择壁厚为1.2mm的O形管，相比选择壁厚为1.0mm的H/2型管，成本增加了20%，这样设计是不合算的。而根据附表2可以知道采用H/2（TP2Y）铜管，壁厚为1.0mm时，其耐压可达到6.684MPa，完成符合设计压力的要求，因此这种情况下应该选择壁厚为1.0mm的H/2（TP2Y）铜管。Italsocanbecalculatedasperformula,whenH/2(TP2Y)copperpipebears4.15Mpapressure,thewallthicknessrequiredist=0.584mm.Therefore,selectingH/2(TP2Y)copperpipewithwallthicknessof1.0mmcanfullymeetthe4.15Mpadesignpressurerequired,justitisapitythattheH/2(TP2Y)copperpipecannotbefolded,however,wecanusematchedbendtosolveit.也可以根据公式计算，H/2（TP2Y）铜管承受4.15Mpa的压力时，需要的壁厚是t=0.584mm。所以选择壁厚为1.0mm的H/2（TP2Y）铜管是完全符合4.15Mpa的设计压力要求的，只可惜H/2（TP2Y）型铜管都不能折弯，但可以使用与其相配套的弯头来解决。Aspertheabovecalculationandanalysis,TP2Ytypeshallbeselectedascopperpipematerialforthisproject.根据以上计算及分析，本工程铜管材料选择为TP2Y型。三、Copperpipewelding铜管的焊接1、Getreadyfortubing准备与配管1.1examinetheoxygencylinderandacetylenecylinderforenoughquantity检查氧气瓶和乙炔瓶内的量是否足够。1.2checkdrawingrequirement,ensureallpartsarecompleteandundamaged,withgoodfunction.核对图纸要求，保证各部件的齐全无缺，功能完好。1.3ensurepipelineflatandupright,noteallvalvefittingsdirectivity.保证管路光路横平竖直，注意各阀件的方向性。1.4usetapemeasuretomeasurerelativelengthaspersizesandpipediametersrequiredindrawingandrecordthelocationwithmarkerpen.根据图纸要求的尺寸和管径，用卷尺量取相应的长度，并用线号笔几下位置。1.5forlargercopperpipe,afteritisfixed,usecuttingknifetoremoveit,ensurecuttingopeningflushandnon-deformation.较粗的铜管要固定后，再用割刀拆下，要保证割口平齐，不变形。1.6raspthecuttingopeningsharpedgeswithfile,andwipeitwithcleaningcloth.用锉把割口毛边锉平，并用抹布擦拭干净。1.7cleantheweldedpipefittingsurfaceorflaring,hornmouthshouldbesmooth,circular,burr-freeandnocracking,eventhickness,polishcleanthecopperpipeconnectortobeweldedwithabrasivepaper,andwipeitcleanwithdryclothfinally.Otherwise,itwillinfluenceweldingfluxflowandweldingquality.将要焊接管件表面清洁或扩口，扩完的喇叭口应光滑、圆正、无毛刺和裂纹，厚度均匀，用砂纸将要焊接的铜管接头部分打磨干净，最后用干布擦干净。否则，将影响焊料流动及焊接质量。1.8inadditiontoweldingbetweenredcoppers,allpipefittingsshouldbecleanedwithgauzeorstainlesssteelwirebeforewelding,revealingglossymetalsurface.(innersurfaceshouldalsobecleaned,metalfilingandsandgrainsshouldberemovedandcleaned)除紫铜与紫铜焊接外，所有管件在焊接前都应用纱布或不锈钢丝刷清理，露出光亮金属表面。（内为表面均要清理，金属屑及砂粒应清除干净）1.9overlapthecopperpipetobeweldedandinsertinto(notethesizes)andaligncenterofcircle.将要焊接的铜管互相重叠插入（注意尺寸）并圆心对准。1.10copperconnectorandinsertiondepthofcopperpipeandclearanceseethetable.(insertiondepthapproximatelyequivalenttopipediameter)铜管接头与铜管插入深度及间隙见表。（插入深度约等于管径）CopperwiresizeDOmmMin.clearanceMax.clearanceInsertiondepth19.050.0020.0065/8"22.220.0020.0063/4"28.580.0020.00729/32"铜管规格DOmm最小间隙最大间隙插入深度19.050.0020.0065/8"22.220.0020.0063/4"28.580.0020.00729/32"2Protection保护2.1Pipetobeweldedconnecttolowvelocitynitrogenwhenweldingtoavoidoxidation.焊接时应在被焊管通低速氮气，防止氧化。2.2Acetylenegasshouldgetthroughnon-oxidationweldinggeneratortopreventtheoutsidesurfaceofweldmentfromoxidation.乙炔气应通过无氧化焊接发生器，防止焊接物件外表面氧化。2.3Welding焊接2.3.1duringwelding,preheatingshouldbedonetotheweldment,heatthecopperpipeweldingpointwithflame.Whencopperpipeisheatedtopurplered,moveawaytheflameandremaintheweldingfluxontheweldedjunction,maketheweldingfluxmelt,flowintocopperpipewelded.Heatedtemperaturecanreflecttemperaturebymeansofcolors,darkread:about600℃;crimson:about700℃;orangered:about1000℃.焊接时，必须对被焊件进行预热。将火焰烤热铜管焊接处，当铜管受热至紫红色时，移开火焰后将焊料靠在焊口处，使焊料熔化后流入焊接的铜件中，受热后的温度可通过颜色来反映温度的高低，暗红色：600摄氏度左右；深红色：700摄氏度左右；橘红色：1000摄氏度左右。2.3.2duringwelding,gasweldingflameshallnotdirectlyheatweldingrod(phos-coppersolders),addingweldingrodlocationshallbeinoppositeoftheheatingdirection.焊接时，气焊火焰不得直接加热焊条(磷铜焊料)，加焊条位置应与加热方向相反。2.3.3thecomponentseasilydeforminganddamagingathightemperatureconditionshallhaverelativeprotectivemeasures.Equipmentclosetotheweldingpointsshouldbewrappedwithwetgauzeandtheperformwelding.对于高温条件下易变形，损坏的部件应采取相应保护措施。靠近焊接点的设备要用湿纱布包扎接口后再进行焊接。2.3.4duringwelding,whenannealcopperpipeafterwelding,annealingtemperatureisnotlessthan300℃.焊接时，在焊完后将铜管进行退火时，退火温度不低于300摄氏度。2.3.5Afterwelding,cooldown,cleaninternaloxideandweldingslagwithdrynitrogengas.焊接完毕后，冷却，用干燥氮气清理管内氧化物和焊渣。2.4Repairwelding补焊2.4.1repairweldingtheleakpointofweldfoundduringpressuretest.Repairweldingshouldletoutthenitrogengasforsystempressuretest,andafterweldingconductpressuretestagain.在试压过程中发现焊接有渗漏的地方应进行补焊，补焊时要将系统试压的氮气放掉，焊后要重新试压。2.4.2beforerepairwelding,wipecleaningtheoxidelayerofsurfacewithgauze.Afterwelding,removethescalecinder.补焊前要将表面的氧化层，用纱布擦净。补焊后，要将氧化皮清除干净。2.4.3Afterallweldingworkcompletes,blowdownthesystemwithnitrogengas.全部焊完后，要用氮气将系统吹净。2.5Pressuretest试压2.5.1Aftercompletionofcopperpipewelding,closethepipelineforairtighttest.Connectthetestpipelinetothenitrogengascylinderwithhighpressurehose,andinstallapressuregaugewitharangeof5MPa.在铜管焊接完毕后，封闭需要作气密性试验的管路。将该试验管路用高压软管与氮气瓶相连、并装一只量程为5MPa的压力表。2.5.2forcepressureto0.3MPa,remainpressurefor3minutes,examineitforpressuredrop.Ifpressuredropexists,thesystemhaslargeleakpoint,i