低温罐施工技术措施

5.施工技术措施5.1LNG储罐施工5.1.1LNG储罐罐体施工程序（constructionsequence）LNG储罐罐体主要施工程序见“图5.1-1LNG罐罐体施工流程图”。5.1.2罐顶及钢结构预制5.1.3罐顶临时支撑安装5.1.4罐顶板安装5.1.5临时支撑拆除5.1.6铝吊顶安装（1）、铝吊顶预制Ⅰ边缘圈梁的预制边缘圈梁按每8-10m为一段进行预制。边缘圈梁的环板和立板使用等离子切割机进行下料，下料时留出5mm的加工裕量，下料完毕后，使用坡口加工机或刨边机加工边缘；立板使用滚床进行滚弧，滚弧时应注意将滚床辊子表面的毛刺、麻点等杂物清理干净并在辊子表面均匀的缠裹2-3层白胶布，防止划伤铝板表面。圈梁的立板和环板加工完毕后，组对成“T”型，并进行焊接。最后在立板上号线、打孔。圈梁预制时应注意：圈梁的立板与环板间的焊缝应错开250—300mm（如下图）。Ⅱ铝板安装前，将钻好孔的铝肋板安装焊接在铝板上。Ⅲ铝板在预制时应注意保护防止变形及划伤，铝吊顶的预制必须在上铺橡胶板的平台上进行；预制成型的构件必须放置在橡胶板或木板上。（2）、吊杆安装用倒链将吊杆吊起后安装在罐顶的钢梁上，并调节吊杆基本垂直，检查吊杆安装是否牢固，并检查下端是否基本处以同一水平面。（3）、边缘圈梁安装吊杆安装完毕后，将圈梁逐段安装到吊杆上，调节圈梁环板基本处于同一水平面，并组对圈梁间的焊缝，（4）、铝板安装铝板在安装完肋板后从中心向四周进行安装，安装时使用导链和滑轮组将铝板吊起，用螺栓连接肋板与吊柱；安装完部分铝板后组对铝板间的焊缝并进行焊接。铝吊顶周边与圈梁相连接的边缘铝板待铝板安装到周边后，按实际尺寸进行下料、预制并进行安装。（5）、铝吊顶的焊接铝板焊接前必须进行化学清洗或机械清理后再进行焊接，化学清理的方法如下：先使用丙酮将坡口周围的油污清理干净，使用10%的NaOH（40-60℃）清洗4小时，再使用30%的HNO3中和1-3小时，最后用清水清洗后，风干。铝吊顶的焊缝，基本上使用MIG焊进行焊接，对于一些小型构件，使用TIG焊进行焊接。5.1.7压缩环预制安装压缩环在预制场按8-10一段分段预制成型后，在罐吹顶前安装到混凝土上。安装时注意防止压缩环翘曲变形。5.1.8罐顶气举顶升（1）、吹顶前的准备工作Ⅰ吹顶前必须完成的施工项目罐顶包括罐顶附件必须全部安装焊接完毕，并检查合格；铝吊顶必须全部安装、焊接完毕并检查合格；混凝土墙必须施工完毕，并经过养护期，基本达到设计强度。罐顶部压缩环安装焊接在混凝土墙的钢预埋件上安装罐顶的中心柱及临时支柱已拆除。压缩环与罐顶板间的组装卡具准备完毕。Ⅱ吹顶的工装、设备准备a平衡装置的安装罐吹顶前必须安装用钢丝绳和滑轮组成的平衡装置（如下图），罐顶平衡装置共26套沿径向均布。平衡装置的钢丝绳顶部固定在混凝土墙上，下端固定在罐底的铆点上。b密封装置罐吹顶前将厚5mm宽1000mm的橡胶板作为密封装置用临时压板固定在罐顶下部周圈。安装完毕后，是否安装牢固。吹顶前一些大的管孔也要用盲板封死。c风压调节系统为便于观察罐内风压的大小，在罐底部和罐顶部设两套风压计，风压计用“U”型管制作，如下图：在风机进风管处安装调节风门和排风管，便于调节罐内风压。d进风系统吹顶用风通过两台风量为86385m3/h，风压为1671Pa的混流风机供给，进罐的临时通道用δ=10mm的钢板临时封堵，风机通过管线连接在临时封板的开孔上。吹顶时要准备两台75kw的交流发电机作为备用电源。Ⅲ吹顶前检查检查吹顶前，需要完成的施工项目是否已完成。检查确认罐顶与临时支撑之间无点焊等各种形式的连接。确认吹顶的临时设施如平衡装置、密封装置等已正确地进行了安装。风机、发电机、电路、风路以及风力调节系统等在吹顶前必须经过试验，运转正常后方可投入使用。备用风机和备用发电机也必须经过试验。（2）、吹顶Ⅰ吹顶前建立统一的指挥系统，明确指挥信号，编制详细的操作规程。Ⅱ操作员接到送风的指令后，启动风机，观查风压并逐渐加大风量，直至罐顶缓慢浮起。Ⅲ调节风量保证罐顶匀速升。Ⅳ不断观察风压，保证风压稳定。Ⅴ吹顶期间指挥员与操作员不得擅自离岗。（3）、压缩环和罐顶的组装焊接罐顶吹至顶部与压缩环靠紧时，在罐顶上每隔0.5m焊接一个龙门板，用扁楔子组装压缩环与罐顶焊缝、点焊并进行焊接。组对形式如下图所示：（4）、停风和临时设施的拆除罐顶板和压缩环焊接完毕后，停止送风，并拆除吹顶用的平衡装置、密封装置等临时设施；将点焊的焊点、疤痕等打磨干净；拆除风机等送风设备及管线、拆除进罐的临时堵板。5.1.9角部保护处的施工（1）、罐底与罐壁连接处施工程序罐底衬板施工罐底衬板施工（碳钢底板）混凝土墙内第一圈防潮衬板施工罐底混凝土层浇筑保温层施工第二层罐底的边缘板施工角部第一圈9%Ni钢保护板安装混凝土环梁施工内罐罐底边缘板施工（2）、罐底衬板与罐壁第一圈混凝土防潮衬板的施工Ⅰ罐底衬板在罐底混凝土施工完毕后，铺设并进行焊接，焊接时要注意采取合理的焊接顺序，防止焊接变形；罐底衬板与罐比预埋件连接的边缘板根据实际尺寸进行下料。Ⅱ罐壁第一圈防潮衬板待罐底板施工完毕后进行施工，防潮衬板使用倒链吊起紧贴在罐壁上，点焊后焊接在混凝土的预埋件上。（3）、第二层底板的边缘板先进行号出每块板的位置线，然后用吊车顺序进行铺设并进行组对，组对时应注意保证坡口间隙为3±2mm,错边量不大于2.5mm;边缘板进行焊接时，先用手工焊进行打底焊，焊接完毕后，打磨并进行着色检查，然后再进行填充焊接。（4）、第二层底板的边缘板焊接完毕后，进行真空试验，合格后号出第一圈9%Ni钢壁板的位置线，安装定位板后组对第一圈壁板。壁板安装后检查垂直度、椭圆度、焊缝间隙、纵缝错变量全部合格后，现焊接纵缝再焊接壁板与底板的角焊缝。（5）、混凝土环梁施工完毕后，安装内罐罐底边缘板，安装方法基本与第二层底板边缘板相同。5.1.10罐壁施工（1）、混凝土墙内衬板安装吹顶完毕后，先将角部保护区域内剩余部分的衬板安装完毕，再安装其它衬板。其它衬板安装前，先在罐内将混凝土墙内衬板预制成长条，然后用卷扬机吊起安装在混凝土墙内的预埋件上，安装时应注意尽量使钢板贴紧混凝土墙。（2）．角部第二层护板及保温层的施工Ⅰ角部保护部分的混凝土墙内衬板施工完毕后，安装角部第二层护板。安装前，先将环缝垫板安装好，再安装壁板，壁板安装前，立缝两侧各点焊三个方帽环缝点焊9-10个方帽。Ⅱ组对时先使用圆楔子和背杠（用10#槽钢制作）固定环缝如下图：Ⅲ纵缝使用球罐卡具固定如下图：（3）、内罐施工Ⅰ围第一圈壁板a、号壁板位置线在边缘板上号出壁板的安装位置。壁板内侧安装基准线R考虑到纵缝的焊缝收缩，R必须满足以下要求：R≥图纸要求的焊后壁板内径+（1.5×第一圈壁板的焊缝数量）/2πb、点焊壁板安装限位板沿壁板内侧安装基准线点焊壁板内侧限位板，沿壁板外侧基准线（内侧基准线半径R+第一圈壁板板厚）点焊壁板外侧限位板。每隔1m点焊一限位板，内外交错，立缝两侧100mm处必须有限位板。（如下图）C、围第一圈壁板围第一圈壁板时，通常从0°或90°、180°、270°开始，先确定第一张壁板位置并安装第一张壁板。然后从该张壁板开始向两边同时围板。板与板间的纵缝先用两马卡具进行固定，每条纵缝至少需要三套卡具。第一圈壁板围完后，每张板上安装两套丝杠用以调整壁板垂直度。Ⅱ围其它各圈壁板a其它各圈壁板围板的方法与第一圈板基本相同，但是围板前要做好以下准备工作：*在所要围的壁板上点焊用于悬挂三角架的蝴蝶板（每隔2500mm点焊一个）以及用于组对纵缝的方帽（每侧3个）。点焊位置如下图：*在下一圈壁板上悬挂三角架，搭设跳板、护栏作为施工用脚手架。*在距下一圈壁板上口250-300mm处点焊龙门板，每隔1500mm点焊一个，每张壁板上点焊9个。b、围板时纵缝通过两马卡具进行固定；环缝使用1.2m的背杠进行固定（如下图）。Ⅲ壁板找正a、第一圈壁板找正第一圈壁板的几何尺寸是否准确对于整个罐体几何尺寸有非常重要的影响，因此必须认真对第一圈壁板进行找正。*用两马卡具调整坡口的间隙及错边量：错边量≤1.5mm*用加减丝杠调整壁板垂直度。其允许偏差：±3mm*用千斤顶调整壁板上口水平度。相邻两板上口水平高差≤1mm；整个圆周上口水平高差≤6mm。在调整上口水平度时，在边缘板下加垫铁，使边缘板与壁板下口间的间隙保持为0。*第一圈壁板的椭圆度主要通过限位板的准确度来保证。椭圆度≤20mm。局部椭圆度达不到要求时，可使用方楔子进行调整。找正时必须对椭圆度、垂直度、水平度同时进行调整，保证“三度”全部合格。找正完毕后，在壁板内侧每3米点焊一个支架对壁板进行固定。b、其它各圈壁板找正在施工中如果第一圈壁板的椭圆度和上口水平度严格控制在允许偏差之内，并且每张壁板的几何尺寸都符合规范要求的情况下，按正常的程序围板，当壁板垂直度和纵缝调整合格后，一般情况下，椭圆度和上口水平度也能达到规范要求。所以，其它各圈壁板的找正主要是对垂直度进行调整。每一圈板的垂直度都必须认真调整并做好记录。每一圈壁板的垂直度都将作为下一圈壁板找正的依据。垂直度的调整主要通过调整纵缝的间隙实现。减小纵缝上半部分的间隙使壁板内倾，增大纵缝上半部分的间隙使壁板外倾。当垂直度偏差太大难于调整时，可使用倒链进行调整。找正时每张壁板必须测量三点以上，除保证该张壁板垂直度符合要求外，还应对其下方壁板的垂直度偏差进行修正，保证罐整体垂直度符合要求。垂直度偏差：≤3/1000板宽；罐壁总体垂直度偏差≤50mm。Ⅳ纵缝组对a纵缝组对从内侧进行。使用两马卡具，通过圆楔子、扁楔子调整纵缝间隙及错边量。组对间隙为4-6mm；错边量不大于1/10板厚，且不大于1.5mm。b纵缝组对完毕后，在内侧点焊4-5块防变形板，防止焊接过程中出现角变形。c因第1-4圈壁板纵缝为双面焊且焊接时先焊接外侧再焊接内侧，为防止焊接时出现角变形，组对时应采取反变形措施。如下图所示：Ⅴ加强圈加强圈安装前，先在罐外分段预制成型，分段长度约10—12m，预制完毕后用弧型样板检查其内弧偏差，间隙不大于4mm；检查弦高偏差不大于10mm。加强圈所在罐壁安装焊接完毕后安装加强圈，安装时先将加强圈支架安装在罐壁上，再分段进行安装。Ⅵ临时通道处的壁板内罐中的全部施工项目（包括罐底板）施工完毕后，将罐内工装、卡具及施工废料等清理干净、检查确认后安装临时通道处的内罐壁板，安装时使用电动葫芦和倒链进行就位，用球罐卡具和背杠进行组对。Ⅶ焊接内罐的纵缝的焊接全部采用手工焊，电源极性尽量采用交流；环缝采用埋弧自动焊；通道处壁板全部采用手工焊进行焊接。焊接时要注意控制焊接线能量，焊接的同时做好施焊记录。（4）、内罐安装时的脚手架搭设方法Ⅰ、将挂壁三角架安装在焊接于罐壁板上的蝴蝶板上,约每2.5米安装一个三角架；Ⅱ、在三角架上并排铺设三排钢跳板并用铁丝绑扎牢固；安装时留出小平台的安装位置；Ⅲ、安装栏杆。先安装立杆，再安装横杆；Ⅳ、将小平台安装于焊在壁板上的蝴蝶板上并安装小斜梯；Ⅴ、将竹编板铺在跳板上并用竹编板封闭栏杆；Ⅵ、检查各部位是否牢固稳妥。内脚手架简图：5.1.11罐底施工（1）、罐底边缘部分施工要在储罐升顶前完成。（2）、其它部分的施工基本与内罐罐壁同时施工，在进罐通道未封闭前完成施工，基本施工程序如下：第二层底板中幅板（9%Ni）施工铺50mm的干砂绝热层施工加强混凝土层施工碳钢衬板施工基础检查、验收第二层底板中幅板（9%Ni）施工铺50mm的干砂绝热层施工加强混凝土层施工碳钢衬板施工基础检查、验收检查验收上层底板中幅板施工铺50mm的干砂绝热层施工加强混凝土层施工检查验收上层底板中幅板施工铺50mm的干砂绝热层施工加强混凝土层施工（3）、钢衬板和它上部的混凝土层全部施工完毕后，其它部分从进罐通道对面按上述程序逐渐向外施工如下图：（4）、罐底施工前要对罐基础进行验收。验收的主要内容有：罐底的标高、罐底平整度以及基础表面质量。基础表面不得有蜂窝、裂纹等缺陷。（5）、上层及中间层罐底板的铺设上层及中间层罐底板均为条状排板，铺设时从内向外先号线再铺板。铺板时先铺设条状大板，再铺设周边小板；每铺三排板作为一个单元，铺设完毕后进行焊接并进行焊接检验，然后进行下一层的施工，最上层底板焊接完毕后继续下一个单元的施工。铺板时为防止板变形，吊板应使用专门的吊装梁如下图：（6）、焊接顺序中间层底板和最上层底板焊接时应采取合理的焊接顺序：焊接时先焊接短焊缝，再焊接长焊缝，每条焊缝焊接时采取分段跳焊的方法，减少焊接变形。基本焊接顺序如下图所示：（7）、中间层底板和最上层底板均为搭接结构，铺设时要保证搭接宽度不小于40mm。（8）、三层板重叠搭接的部位焊时要注意：先将最上面一层板的角部撬起，将起覆盖的位置焊好再焊接其它部位，如下图：（9）、底板焊接完毕后应进行真空试漏。如下图所示：（10）、底板焊接完毕后检查其凹凸变形及焊缝是否符合规范要求。5.1.12储罐内部管道、下降管等安装5.1.13罐体试验（1）、罐底板和罐顶板以及罐壁衬板组件焊接完毕后，按BS7777的要求进行真空试验。（2）、内罐罐壁焊接完毕后按BS7777进行X射线探伤检查。（3）、内罐安装焊接完毕后，进行充水试验，充水前编制详细的充水方案。充水试验的流程如下图：Ⅰ充水按充水曲线进行，充水后检查罐壁、罐底等有无泄漏现象，罐壁有无异常变形，并定期测量罐基础沉降情况。Ⅱ充水试验合格后，进行排水。排水时先用大泵将水基本排出罐外，再用自吸泵将大泵抽不到的水排出罐外，最后用人工将罐内的水清理干净。Ⅲ排水完毕后，用干燥的空气将罐内吹干。（4）、充N2储罐全部施工完毕后，利用液氮罐车对内充N2，试验完毕后，往罐内吹压缩空气。5.1.16罐脱水、干燥及设备安装5.1.17罐绝热施工5.1.18罐外部工艺系统试运转5.1.19罐吹除、钝化、冷却与移交5.1.20储罐焊接5.1.20.1 WeldingmanagementandWeldingProcedures(1) WeldingshallbeinaccordancewithBS7777.Allverticalandhorizontalseamsoftheinnertankshellshallbeweldedbythefollowingmethods:manually,semiautomatic,orbymachine.(2) Allweldingprocedurespecificationsandprocedurequalificationrecordstobeusedfortheconstructionofthetanks,includingthoseforprefabrication,repair,tackandattachmentwelds,shallbeacceptedbyPurchaser/MainContractorpriortotheworkbeingperformed.WherenewWPS/PQRisrequired,itshallbeoncontractmaterialsandshallfollowimpacttestingrequirementasfollows, ThepositionsofCharpyimpacttestat–196deg.Cshallbe:WeldmetalcenterlineFusionlineFusionline+2mmFusionline+5mm(3) Theweldingproceduresusedforallweldsandtheradiographicinspectionprocedureshallclearlybeindicatedinconstructiondocuments.(4) Noweldingispermittedontheinnertankaftercompletionofthehydrotest.(5) WeldingConsumables* Fillermetalfor9%nickelweldingshallconformtoASME/AWSSFA5.11and/orSFA5.14.FillermetalsandfluxesshallbeselectedbyTankContractorbasedonprovidingstrength,ductility,soundnessandsuccessfulLNGtankexperience.* Eachlotorheatoftheausteniticstainlesssteelwelding(filler)materialsshallmeettherequirementsofSectionVIII,Div1UHA-51(e)and(f).AllweldingproceduresshallbequalifiedinaccordancewithBS7777orASMECodeSectionIX.* TankContractorshallimplementarigoroussystemtocontrolthesegregationandstorageofweldingconsumables.(6) WeldingQualificationandIdentification* QualifiedwelderstestedinaccordancewiththerequirementsofBS7777orASMECodeSectionIXshallcarryoutallwelding.Theweldersshallbenewlyqualifiedirrespectiveofanypreviousqualifications.TankContractorshallissueanindividualcertificatewithphotographtoeachqualifiedwelder.Welderswhoarenotinpossessionoftherequiredcertificationandidentificationshallnotbeallowedtodoanywelding.TankContractorshallalsoimplementanidentificationbadgesystemtoclearlyshowwhichweldersarequalifiedforwhichmaterials.(7) Inspection* RadiographicInspectiona) Theradiographicextent,techniquesandacceptancecriteriafortheinnertankshallbeinaccordancewithBS7777.b) Allverticalandhorizontalbuttweldsofinnertankshell,annularplatebuttwelds,innertankstiffenersandinternalpipingshallbeinspectedbyradiography.c) Leadscreensshallbeused,saltscreensshallnotbepermitted.Radiographicinspectionshallfollowassoonaspossibleafterwelding,andtheinspectionsshallbeco-ordinatedwiththePurchaser’s/MainContractor’sinspector.d) Radiographyfor9%nickelweldsshallbebyX-raymethodswithamaximumfocalspot2.5x2.5mm.AllpersonnelperformingCodeevaluationsshallmeetASMESectionV,SNT-TC-1A,LevelIIorequivalentqualifications.Thefilmtobeusedforradiographyshallbeultrafine,highcontrasttypee.g.KodakAAorAgfaD7.* LiquidPenetrantExaminationa) LiquidpenetrantexaminationfortheinnertankshallbecarriedoutaccordingtoBS7777.TheSecondaryBottomAnnularPlatesshallhavethesameLiquidPenetrantExaminationRequirementsastheInnerBottomAnnularPlates.TCPweldsshallhavetherootpassandthefinalweldexaminedbyLiquidPenetrant.TheweldbetweentheSecondaryBottomandtheTCPshallhavetherootpassandthefinalweldexaminedbyLiquidPenetrant.* SolutionFilmTestinga) VacuumboxtestingshallbecarriedoutinaccordancewithBS7777.Allweldsoftherooflinerplatesshallbevacuumboxtestedbeforeconcreteplacementontheroof.Vacuumboxtestingofthebottomandsidewallvaporbarrierweldsshallbecompletedbeforecommencinganyoperationsthatcoveruptheplates.Weldsbetweenlinercomponents(e.g.walllinertobottomliner)shallbevacuumboxtested.c) AllsecondarybottomandTCPweldsshallbevacuumboxtested.d) Innertankbottomplateweldsshallbevacuumboxtestedbeforeandafterhydrostatictesting.e) Theinnertankshell-to-bottomTeejointshallbepressuretestedforleakageusingasolutionfilminaccordancewithBS7777,Part2,para.11.13.3.3.5.1.20.2底板焊接BottomPlate（1）最外层底板材质为ASTMA516Gr60厚度δ=5mm，主要使用CO2气体保护焊进行焊接，点焊、局部短缝使用手工焊进行焊接。ThematerialusedforthebottomplatsofoutmostlayerisASTMA516Gr60withtheirthicknessof5mm,applyCO2gasshieldedweldingmethodtothemandapplymanualweldingmethodtospotweldingandpartsofshortweldjoint.（2）中间层底板材质为ASTMA533Type1厚度δ=5mm，使用手工焊进行焊接；中间层边缘板材质为ASTMA533Type1厚度δ=10mm，使用手工焊进行焊接。ThematerialofbottomplatesofinnerlayerisASTMA533Type1withtheirthicknessof5mm,applymanualweldingtothem.ThematerialofrimplatesofinnerlayerisASTMA533Type1withtheirthicknessof5mm,applymanualweldingtothem（3）上层底板材质为ASTMA533Type1厚度δ=6mm，使用手工焊进行焊接；上层边缘板材质为ASTMA533Type1厚度δ=25mm，使用手工焊进行焊接。ThematerialofbottomplatesofupperlayerisASTMA533Type1withtheirthicknessof5mm,applymanualweldingtothem.ThematerialofrimplatesofupperlayerisASTMA533Type1withtheirthicknessof5mm,applymanualweldingtothem5.1.20.3罐壁焊接ShellPlate（1）罐壁板9%Ni（ASTMA533Tpye1）部分：除最后一道环缝外其余环缝均采用埋弧自动焊进行焊接；纵缝、最后一道环缝以及进罐通道最后两张板的焊缝使用手工焊进行焊接。Fortheshellplateswiththeirmaterialof9%(ASTMA533Tpye1):exceptthelastcircumferentialweld,applyautomaticsubmergedaceweldingtotherestofthem;forthelongitudinalweld,thelastcircumferentialweldandtheweldofthelasttwoplatesusedforwalkwayforenteringthetank,applymanualweldingtothem.（2）与混凝土墙相贴的碳钢板的焊接采用手工电弧焊。Forthecarbonsteelplatesabuttingupontheconcretewall,applymanualweldingtothem.5.1.20.4拱顶焊接DomeRoof（1）拱顶结构的预制焊接根据焊缝的具体情况分别采用手工焊、CO2气体保护焊或埋弧焊。Forthefabricationofdomeroof,applymanualweldingandCO2gas-shieldedarcweldingorsubmergedarcwelding.（2）拱顶结构的安装采用手工焊进行焊接。Applymanualweldingtotheerectionofdomeroofstructure.（3）拱顶瓜皮板的焊接主要采用CO2气体保护焊进行焊接。ApplyCO2gas-shieldedarcweldingtotheroofplatesofdomeroof.（4）铝吊顶的焊接采用熔化极气体保护焊（用氩气进行保护）。Applymetalgasweldingtothealuminiumsuspensiondecks(argongas).（5）拱顶上的螺柱采用提升式螺柱焊。Applyliftingstudweldingtothestudsofthedomeroof.5.1.20.5焊接材料WeldingMaterials本工程中涉及到的母材及对应的焊材如下表：Basemetalandcorrespondingweldingmaterialsinvolvedinthisprojectareasfollows:序号No.母材BaseMetal焊接方法WeldingMethod焊材型号及规格TypeandSpecificationofWeldingmaterial1ASTMA533TYPE1(9%Ni)手工焊(SMAW)ENiCrMo-4φ2.5\φ3.2\φ4.0埋弧焊(SMW)ERNiCrMo-4φ2.6andassortedflux2ASTMA516Gr60&Gr70ASTMA36(低碳钢)(lowcarbonsteel)手工焊(SMAW)E7018φ2.5\φ3.2\φ4.0CO气体保护焊(GMAW)E71T-9φ1.2埋弧焊(SMW)A5.17F6A4-EL83ASTMB209-ALLOY5083-0(铝合金)(AluminiumAlloy)气体保护焊(GMAW)ER5183φ1.24ASTMA312TP304(不锈钢)(SS)手工焊(SMAW)E308Lφ2.5\φ3.2\φ4.0Fillermetalfor9%nickelweldingshallconformtoASME/AWSSFA5.11and/orSFA5.14.FillermetalsandfluxesshallbeselectedbyTankContractorbasedonprovidingstrength,ductility,soundnessandsuccessfulLNGtankexperience. Eachlotorheatoftheausteniticstainlesssteelwelding(filler)materialsshallmeettherequirementsofSectionVIII,Div1UHA-51(e)and(f).AllweldingproceduresshallbequalifiedinaccordancewithBS7777orASMECodeSectionIX. 5.1.20.6工程施工中9Ni%钢（ASTMA533Tpye1）焊接的工艺参数及注意事项WeldingParameterandPrecautionsforWeldingof9%NiSteel（ASTMA533Tpye1）duringConstruction（1）手工焊ManualWelding①平焊FlatPositionWelding主要坡口形式：Maingroovetypesareasfollows:焊接材料weldingmaterial：ENiCrMo-4φ3.2/φ4.0烘干温度dryingtemperature:200-250℃烘干时间dryingperiod:0.5-1h焊接电源特性characteristicsofweldingsource:交流(A.C)焊接参数weldingparameter:焊接层次WeldLayer焊材型号TypeofWeldingMaterial电流Current(A)电压Voltage(V)焊接速度WeldingSpeed(cm/min)打底焊道BackRunENiCrMo-4/φ3.270-9020-2513-16填充焊道FillerPassENiCrMo-4/φ3.270-11020-2513-16填充焊道FillerPassENiCrMo-4/φ4.095-14020-2513-16②立焊\横焊VerticalWelding/HorizontalWelding主要坡口形式：Maingroovetypesareasfollows:焊接方法weldingmethod：手工焊（SMAW）焊接材料weldingmaterial：ENiCrMo-4φ3.2/φ4.0烘干温度dryingtemperature:200-250℃烘干时间dryingperiod:0.5-1h焊接电源特性characteristicsofweldingsource:交流(A.C)焊接参数weldingparameter:焊接层次WeldLayer焊材型号TypeofWeldingMaterial电流Current(A)电压Voltage(V)焊接速度WeldingSpeed(cm/min)打底焊道BackRunENiCrMo-4/φ3.265-9020-2513-16填充焊道FillerPassENiCrMo-4/φ3.265-10020-2513-16填充焊道FillerPassENiCrMo-4/φ4.085-13020-2513-16③手工焊时的注意事项：Precautionsduringthecourseofmanualarcweldingareasfollows:焊接前不需要预热，但是焊接层间温度必须控制在150℃以下；焊接时尽量采用多层多道焊，为减小焊接线能量，每一焊道焊接时尽量采用快速不摆动的操作方法，在横、立仰焊必须摆动焊条时，采取快速的“Z”字摆动；禁止在母材上引弧，引弧时应在坡口内引弧，收弧时要填满弧坑。Preheatisnotnecessarypriortowelding,buttheinter-passtemperaturemustbecontrolledbelow150℃.Applymulti-passweldingasmuchaspossible.Inordertoreduceweldheatinput,applyweldingathighspeedandwithnoweavingtoeachofpass.Whenitisnecessarytoapplyweldingwithweavingtohorizontalandverticalwelding,adoptZ-typeweavingathighspeed;itisstrictlyprohibitedtostrikethearconthebasemetal,startthearcwithinthegrooveandfillinthecraterwhilefinishingthearc.（2）埋弧焊SubmergedArcWelding焊接位置：横焊Weldingposition:horizontalwelding坡口形式typeofgroove：焊接材料weldingmaterial：ERNiCrMo-4φ2.6&A5.14焊剂烘干fluxdrying:200-300℃,烘干时间dryingperiod:1h焊接电源的特性characteristicofweldingsource：方波交流（SquareWave.A.C）焊接参数weldingparameter:焊接层次WeldLayer焊材型号TypeofWeldingMaterial电流Current(A)电压Voltage(V)焊接速度WeldingSpeed(cm/min)打底焊道BackRunERNiCrMo-4/φ2.6290-32026-2830-55填充焊道FillerPassERNiCrMo-4/φ2.6300-36026-2830-55注意事项:焊接层间温度不大于150℃；焊接线能量控制在35-40KJ/cm以下；封底焊时背面填加焊剂辅助成型，焊接完一侧后，背面进行清根并进行PT检查，合格后在进行焊接。Precautionsareasfollows:Interlayertemperatureisnotabove150℃；weldheatinputiscontrolledbelow35-40KJ/cm.Whileperformingbackwelding,fillthefluxonthebacksidetoassisttoform,completeweldingoneside,carryoutbackgougingandPT,ifqualified,goontocarryoutwelding.5.2PipinginstallationTheafflictedpipinginsideoftheLNGtankisofstainlesssteel.Allshallbeprefabricatedinworkshop.Cutbypowersawandweldedbyargon-electricweld.Cleanthetwosidesoftheweldwithsteelbrushandspecialgrinder.ApplyX-raydetectionforbuttedweld.Simultaneously,prefabricateanderectthepipesupportanditsafflictedstructure.Aftererection,executepressuretest,blowandtightnesstestaccordingtothespecification.LNGmediumpipingsystemshouldbeblowedandkeptdry.5.3LNGpumpsinstallationBeforeinstallation,carefullycheckthepumpsaspertheproductmanual,andthenexecuteinstallationundertheinstructionofrepresentativeofmanufacturer.LNGpumpinstallationshouldbeexecutedafterthequalifiederectionofitssupport,andstrictlyavoidthewaterimmerge.Afterqualifiedinstallation,executetestrunaspertheproductmanualsuppliedbymanufacturer.5.4ElectricalandInstrumentWorkTheinstallationofelectricalandinstrumentequipmentandcablewillbeexecutedsynchronouslyasconditionpossessing,andthelooptestingshallbeundertakentimely.5.4.1ElectricalConstructionTechnicalPlanElectricalworkofthisprojectmainlyincludesgroundingsystem,lightingsystem,heatingtracingsystemandallrelevantworksinregardsoftankbodiesintankfarm,suchassteelconduitinstallation,cablelayingandwiring,assembleofelectricalequipmentsandtestingetc.⑴ConstructionofLightingandGrounding--Duringtheconstructionofelectricalworktheelectricaldisciplineshallmakegoodcoordinationwiththecivildiscipline;theconstructionpersonnelshallmakeclearknowofthegroundlevelanddrawings.Theconstructionshallbeexecutedstrictlyaccordingtothedrawingtoavoidtheomittingembeddingofearthbar.--Beforegrounding,testthesoilreceptivityandcorrosivenessandtheresistanceoftheexistinggroundingnet.Addearthbarincasetheresistanceisabove2ohms.--Theembeddeddepthofthegroundingcableshallnolessshortthan700㎜.--Allconnectionbetweenthegroundingconductorshallbeconnectedbythermoweldaccordingtothedrawings.Adetailedplanconcernedabouttheoverlaplengthandoverlaptypeandweldingrequirementshallbepreparedbeforeconstructionandsubmittorelevantdepartmentforapproval.Theweldershallbequalifiedwithcertaincertificate.--Thecableextendlengthoverthetankcoffershallbenosmallthan2m.Allthemetalwithoutelectricityshallbegrounded.--Eachnolongerthan100mofpipelineincentraltankfarmpipeandeachnolongerthan20mofpipelineinsteamcrackingtankfarmshallprovidegroundingpointwhichconnectedwiththemaingroundingnet.--Thegroundplateofequipmentshallbeofsamematerialwiththebaseplate,andtheweldingareashallbecoated.Whenmakingthegroundingplate,thepaintingandfireproofingshallbetakeintoconsideration.Thedimensionoftheexposurepartshallbestrictlyaccordancewiththestipulationsinbiddingdocuments.--Dotheconstructionstrictlyaccordingtothedrawingspecification.IfthereissomethingthatconflictwiththerequirementtheconstructionshallnotbecontinueduntilpermissiongivenbyrelatedDepartment.--Theundergroundgroundingbelongstoconcealedwork,sobeforeconcealingjointcheckmustbetaking.Usefinesoilwithoutstone,brickbatandcorrosivenesssoiltobackfillandcompactlayerbylayer.--Smearelectricalcompoundgreaseontheconnectionpartbetweenthegroundingcableandtheplate.5.4.2HeatingTracingsystem.--Thetracinglineshallbecheckedofthetype,specificationandtechnicalcapacityaswellastheinsulationtestbeforeinstallation,andalltheseinspectionsshallbefiled;installationoftracinglinecanbecarriedoutonlywhenallthetestsandinspectionsarefoundqualified.--Damageoftheinsulatinglayerofthetracinglineshallbestrictlyprohibited,andthetracinglineshallbewellprotectedlestbeingdamagedbytheconstructionpersonnelofotherdiscipline.--Thelaggingworkcanbeperformedonlyafterthecompletedworkbeingcheckedasqualifiedandacceptedwithsignature;damagingthetracinglineandequipmentbythelaggingpersonnelshallbeprohibitedduringconstruction,andthehand-drillusedbythelaggingpersonnelshallbefixedthelengthofaiguilleswithblockagepinaccordingtothelaggingdepth,lestdamageofthetracinglinebecauseoflongaiguillesandcausingunnecessaryworkredone.--Thetracinglinewithlaggingshallbewellprotectedandthewarningnoticeforwhichshallbeprovided,tramplingandhittingofthetracinglinewithlaggingshallbeprohibited.--Severaltracinglinescanshareonepowercircuitforthepurposeofpreventingfrostbite,andonebranchcircuitswitchcanonlyaffordforfivepipingorinstrumenttracingline.--Theoutdoortemperaturecontrollershallbeabletocontrolthecontactorthatsupplyandstopthepowersupplytothetracinglinetrippingcircuit.--Thepipelinefrostbiteprotectionshallincludethetracingofallthein-lineelementssuchasflanges,pumps,valves,equipment,supportsandattachedequipment,withproperlyincreasedtracinglinelengthsoastoconveniencethedismantleandmovingofflanges,valvesandinstrument.--Generally,theinstrumentpressurepipeshouldbeheattracedandinsulated,andsamekindoftracingcableshallbeusedfortheinstrumentandpressurepipe,andremovableinsulationlayershallbeappliedtoeachinstrument.--ThetemperatureadjustingfacilityorRTD,whichareinstalledontheoutsidewalloftheequipmentorthepipe,shallbeconnectedtothetemperaturecontrollertocontroleachheatingcircuitautomaticallythrutheindependenttemperaturecontroller.--Aseparatecontrollabletracinglinemustbeprovidedforeachprocesspipe,andthetracinglinefordifferentprocesslinecannotbeintroducedfromsamebranchcircuitswitch.--Thetracinglineshallbelaidparallelingtothepipe,spinningortwistingandinstalledontwoinsulatinglayersarenotallowed.--Alltheimportantelectricalelements,controlequipment,instrumentandremotecontroljunctionboxshallbelabeledaccordingtothedrawings.--Thepowersupplycableandthetracinglinecannotshareonejunctionbox.--ThetracinglinesandRTDloopsshallbelabeledthruSSlabelswithSSwire,andthelabelsshallbefixedonthecableswithineachjunctionbox;eachheaterjunctionboxandeachRTDcasingshallhaveaindependentlabel.--TracingmonitorandremoteconditionshallsubjecttotheP&ID.--Alltracinglineshallbecheckedoftheinsulationwith500Vmegameteratsite.--Performthecontinuitytestforeachcircuittoassureallelements,instrumentandotherequipmentsarecorrectlyconnected.Afterthecompletionofinstallation,checkandtestthepowercableandcontrolcabletogetherwiththetemperaturecontroller,relayorotherattachedequipment.Theelectricaloperatabilitytestforalltheequipmentmustbeperformedtocheckthecorrectroutingandoperatingsequencetoconfirmthequalificationstatus.--ThetestspecificationpleasereferstoIEEE515.--Thecopyofthetestreportshallbesubmittedtotheclientwithintwoweeksafterthecompletionofinspectionandtest.5.4.3TechnicalrequirementsandinstallationmeasuresforInstrumentationworks⑴GeneralInstructionThisprojectofGuangDongLNGTerminalconsistsofsevenpackages,scopeofpackage4.onlyincludesinstallation,assembleoftankbodiesandrelevantpiping,painting,supportandinstrumentationworksetc.InstrumentationworksismainlyincludingsuchrespectsastransportationoftheequipmentfromthePurchaser’swarehousetothesite;Intermediatestorageatsiteifnecessary;Allcabling,connecting,labeling,junctionboxes,testingoffieldinstrumentsintankarea.Besides,supplyofinstallationmaterialsneededtoputtheinstrumentsinfullworkingorderareincludedifnototherwisestated.ThisproposalisworkedoutbasedonbiddingdocumentsissuedbySTTSandrelevantstandardcode,moreexperiencesinsimilarworksengagedaswell.⑵InstallationPractice①Safetyatworka.Allavailablemeasuresshallbetakenattheinstallationsitetoavoiddangeroffireandaccidents.b.Thewearingofsafetyhelmetsiscompulsoryatthesite.c.Thecontractorisresponsibletoimmediatelynotify,onhisowninitiative,anydisturbancebroughttohisattentionconcerningthedeliveryorwork.②Manpowera.Thecontractorundertakestoemployskilledlabouronlyandgoodqualitymaterialsfortheinstallationwork;b.Asachemicalproject,ithasahighlevelofautomaticcontrol,socontractorshallprovidecompetentandskilled,practicaltechniciansthatworkedonforeignworkandbefamiliarwithprocedureoftheforeignconstruction.Inordertodecreasethecost,technicianshallcarefullysurveyandrechecksiteanddrawingsinpriorconstruction,andproduceestimatedplanofmaterial.c.Technicianshallwritebeginninglogforunitworkinadvanceensuringprogresssharply,introduceemphasisandcharacteristic,traintheworkershowtoperformaction,makethemknowexactworkingmethodinorderforhighquality.d.AWeeklyManpowerReportshallbefiguredoutroutinely.③Testequipment,installationtoolsandmethodsa.Ifthecontractisawarded,wehaveavailable,onsitefullworkshopfacilitiesandtestequipmentfortheworkinvolved.Alistoftestequipmenttobeusedshallbesubmittedforapproval,thestandardofaccuracyofwhichshallbebetterthanthemanufacture’sstatedaccuracyforinstrumentundertest.b.Up-to-dateandwell-provenmethodsofinstallationshallbeused.c.Theinstallationshallbecarriedoutwithgreatcare,clarityandneatness.d.Theinstallationtools(especiallycompressiontools)shallbeingoodworkingorderandintendedfortheworkinvolved.④QualityinspectionDuringtheworkthecontractorhastodoowninspectionsaccordingtoitsownqualityprogram,andwhenfinishingoneworkprocedure,technicianshallwritequalityinspectionrequestreport,andinforminwritingPurchaser”engineerandQApersontocarryoutqualitycheckoftheworkcompleted,andproductalogasdocumentfile.⑤Cooperation Weshallactivelycooperatewithprocesspersonandacquirereasonablesuggestionsaboutinstrumentinstallationandrunninginordertomakinginstrumentinstallationmorereasonable.⑶Installationworkandmaterials①Allinstallationmaterials,equipmentandcomponentsmustbeofhighquality.Theymustbesuitableforcircumstancesprevailingatachemicalplant.②ThePurchaserinwritingmustapproveallmateriasandequipmentthatisnotexactlymentionedinthisspecification.Thisapprovalisrequiredforcolou