仪表防爆及接地系统施工方案

仪表防爆及接地系统施工方案

ConstructionSchemeforInstrumentExplosionproofandEarthingSystem中，防爆施工对装置的安全运行格外重要：各种工艺参数的检测、显示和掌握都实(DCS)系统的要求越来越髙。正确完成仪表接地系统，对保证设备及人身安全，保证装置安全运行意义重大。为了高速优质地完成装苣防爆及接地施工任务，特编制本方案。编制依据：2」设计施工图及其它设计文件。现行《自动化仪表工程施工及验收标准》。1T安装工程施工及验收标准》。现行《自动化仪表工程质量检验评泄标准》。厂商供给的产品安装使用说明书等技术文件。公司《质量保证手册》、《质量体系子程序》及英支撑性文件。3•工程概况要实物工程量、工期要求及投资等。防爆施工：ExplosioproofConstruction:一般规左：GeneralRegulations:设计要求，并满足使用区域的防爆等级规定。Thestyleofexplosion-proofandwiringforelectricequipmentandinstrumentequipment,whichusedinexplosionandfiredangerousareas,mustaccordwiththedesignrequirementandcontentwithexplosionproofclassstipulation.安装在爆炸和火灾危急区域的仪表、电气设备和材料，必需具有符合现材料的外观应无损伤和裂纹。Concerningelectricandinstrumentalequipmentandmaterialthatisinstalledinexplosionandfiredangerousarea,theirexplosion-proofqualitytechniqueappraisaldocumentandexplosion-proofmanufacturecertificatemustbecompliancewiththenewstandardrequirementofcountiyorvocation・Tliei”earen”tdamageandcrackinappearanceofdeviceandmaterial.在爆炸和火灾危急场所使用的防爆电气、仪表设备，应有铭牌和防爆标志，并在铭牌上标明国家授权的部门所发给的防爆合格证编号。Fortheexplosion-proofelectricandinstrumentalequipmentthatisusedinexplosionandfiredangerousarea,thenameplateandexplosion-proofmarkshouldappearontheequipment,thenumberofexplosion-proofcertificateissuedbythedepartmentofnationalaccreditationshouldbeprovidedonnameplate.任爆炸和火灾危急场所安装的正压通风的仪表盘(箱)、接线箱及电气、仪表设备、除本质安全型外，应有“电源未切断不得翻开”的标志。Thepluspressureventilationinstrumentpanel(box),junctionbox,electricequipmentandinstrumentequipmentinstalledinexplosiveandfiredangerousarea,excepttheintrinsicallysafetype,itshouldhas“Donotopenwhenenergized“notice.仪表电气线路承受的电缆沟、汇线槽、保护管和仪表连接收路在穿越不同防爆等级的爆炸和火灾区域的分隔间壁时，在分隔间壁外，必需做充填密封。Fortrench,cabletray,protectionpipeusedforinstrumentelectriccircuitandinstrumentconnectionpiping,iftheycrosstheseparatedroomindifferentexplosion-proofclassexplosionandfirearea,fillingandsealingshouldbedoneoutsidetheseparatedroom·4.2设备安装ErectingEquipment:承受正压通风防爆的仪表盘(箱)，接线箱，安装后应保证箱内压力维持Fortheexplosion-proofinstrumentpanel(box),junctionboxwithpluspressureventilation,aftertheyareinstalled,thepressureinboxshouldbeensurednolowerthanthepressureislow.畅通，且不宜安装切断阀。Theexplosion-proofinstrumentpanel〔box〕,junctionboxadoptingpluspressureairiness,itspluspressureairinesspipingmustremainaccessibleandshouldnotmountshuttingoffvalue・423在爆炸和火灾危急场所安装的仪表箱、分线箱、接线盒及防爆仪表、电气封盒并用适当填充料密封。外壳上多余的孔应做防爆密封。Fortheinstrumentbox,junctionbox,wiringbox,explosion-proofinstrumentandelectricequipmentwhichinstalledinexplosionandfiredangerousareas,theentranceofcableshouldbesealedwithexplosion-proofsealfilling

Whenoneconduitcontainsmultiplecable,theentrancecanmountsealingboxwithproprietyfillitospareholesinshell.

Doexplosion-proofsealing盖〕密封而连接螺栓应均匀严密，并应有弹簧垫。Coversshouldhavespringsealingwasherforexplosion-proofinstrumentbox,junctionbox,andconnectionbox・Andconnectionboltsandnutsofseparatingandpreventingfaceshallbetightequablyandhavespringwasher.和防拔脱装宜。Theexplosion-proofelectricandinstrumentdevicesshallbeinstalledfirmly.Insidewiringmustbecorrectandfirmwithlooseness-proofandshedding-proofunit・电气线路安装ErectingElectricalcableline:穿越不同等级的爆炸和火灾危急区域分隔间壁的电缆沟的密封措施：Sealingwayfortrenchthatcrossesseparatedwallsbelongingtodifferentclassofexplosionandfiredangerousareas:电缆沟内充砂密封，可敷设一层电缆，充填一层砂，砂层厚约100mm.电缆全部敷设完后，充砂填满电缆沟。Methodoffillingfinesandintotrench:fillingone-layersandabout100mmdepthafterinstallonelayercable・Thetrenchshallbefullofsandafterallcablelayout.在分界处两侧安装隔板，隔板之间充砂，长度不少于lm。Theseparatedboardsshouldbefixedatbothsidesofinterface,zonebetweenboardsshallbefilledwithsand,andthelengthisnolessthanlm.在分界处用阻火密封填料充填。Sealingwithfire-resistantfillingattheinterfaces.汇线槽穿越不同级别的爆炸，火灾危急区域分界处时，可实行的密封播施：Takingairproofmeasureswherecabletraypassesthroughtheinterfaceofdifferentclassexplosionandfiredangerousareas:在分界处作气密砂封。Carryoutsealwithsandattheinterface・在分界处用阻火密封填料充填，形成密封阻挡层。Sealwithfire-resistantsealfillingattheinterfaceandformsealingandresistantlayer.〔线保护管应选用厚壁镀锌管。选用的管件应按危急区域的级别承受适宜的防爆构造形式。Choosethick-wallgalvanizedconduitascableprotectiveconduitlaidinexplosionand・Selectedpipepiecesshouldadoptproperexplosion-proofstructureandtypeaccordingtorequirementsofthedangerousareasclass・43.46性防锈脂。不得在螺纹上缠麻涂铅油、缠绝缘胶带或涂其它油漆。Adoptcylindricalgasthreadtoconnectconduitanddevicesorpipe-pieces.Makesurethateffectiveengagementismorethansixpitchesandlocktightlyequipmentswithlocknut.Thethreadshallbepaintedwithelectricpoly-greaseorconductiveantirustgrease・Notwringhempropes,notwringinsulatedtapeandnotpaintleadoilorotherpainting・仪表电气线路，在防爆区内不应有中间接头，当必需有中间接头时，应在防爆接线箱内进展，且应连接结实、严密，接头良好并有防松和防拔脱装置。Instrumentelectricalcircuitshallnothavemiddlejointinexplosion-proofarea・Ifitisobligatory,jointshallbeintheexplosionjunctionbox,keepconnectionhardandtight,haveallrightelectricalconductivitywithlooseness-proofandshedding-proofunit・线路沿工艺管架敷设时，其位置应在爆炸和火灾危急性小的一侧Whenlaylinealongtheprocesspipestanchion,layoutlocationshouldbeatthesidethatpossibilityofexplosionandfireislittle.当工艺管线内爆炸和火灾危急介质的密度大于空气时，应在工艺管道的上方，反之，应在其下方。Whendensityofexplosionandfiredangerousmediumintheprocesspipeisheavierthanthatofair,itslayoutlocationshouldbeabovetheprocesspipe;onthecontrary,itslayoutlocationshallbebelow.43.7保护管与现场仪表设备连接时，应安装隔爆密封管件并做充填密封，密0.45m。密封管件与仪表之间的连接可承受挠性连接收，并按防爆要求书进展装配。挠性连接收的材质应与使用环境条件相符适合。Whenconnectprotectionpipewithinstrumentequipmentatsite,theexplosion-proofandairtightpipeconnectorsshallbeinstalled,filledandsealed・Makesurethatthedistancebetweenairproofpipeconnectorsandinstrumentequipmentisnomorethan0.45m・Theflexiblepipecanbeusedtoconnectairtightpiecesandinstiumentandmountaccordingtoexplosion-proofinstructionbook・ Atmeantime,flexiblematerialshallagreewithapplicationcondition・本安系统施工：ConstructionofIntrinsicallySafeSystem:本质安全线路及其附件，应具有耐久性兰色标记。Theintrinsicallysafelineandaccessoriesshallbemarkedwithbluewearmark.本质安全线路与非本质安全线路之间应加屏蔽，且保持一泄的距离。Addshieldnettoseparatetheintrinsicallysafecircuitfromthenon-intrinsicallysafecircuitandkeepsomedistancebetweenthem.本质安全线路中的安全栅、隔离器等关联设备的安装位巻，应在安全场接地。Safebars,separatorsandotherrelatedequipmentsintheintrinsicallysafelineshallbeerectedatthesideofsafelocationorintoexplosion-proofdeviceshellthataccordswithconditions・Equipmentsneededearthingshallbereliablygrounded・不同系列的本质安全型仪表及本质安全线路的关联设备，必需有国家授权的部门发给的产品生产许可证和防爆合格证，其型号规格的替代，必需经原设计单位以文件形式确认。Forrelateddevicesofvariousseriesintrinsicallysafeinstrumentsandlines,thei,imanufacture”slicenseandexplosionproofcertificate,approvedbynationalauthoritydepartment,mustbeprovided.Ifwanttoreplacethem,theirspecificationsandtypesmustbeapprovedbyprimarydesignunitinformoffiles.5•接地系统施工：ConstructionforEarthingSystem:一般规定：GeneralRegulations:仪表接地系统一般分为保护接地、信号回路接地、屏蔽接地和本安系统接地四种。Instrumentearthingsystemgenerallycomprisesoffourtypes:safeguardearthing,signalloopearthing,shieldearthingandintrinsicallysafeearthingF线，分支线之间应彼此绝缘。Allearthlingsofinstrumentsystemshouldhaveitsownsystem,everyearthlingsystemshallseparateandconnecttoitsownearthingbus.Busandbranch-lineshouldbeinsulatedeachother.仪表接地系统的接地电阻值，应分别符合各自系统的厂商技术文件或设计文件的要求。Earthingresistanceofinstrumentearthingsystemshouldbecompliancewithrequirementsofmanufacturedtechnicalfilesordesignfilesforrespectiveinstrumentsystem.用芯线与电缆屏蔽层，应在同一侧接地。Whenitisneededtopreventdisturbance,sparecoresofmulti-corecableshouldbegroundedatonepoint.Sparecoresofshieldedcableanditsshieldshouldbegroundedatthesameside.接地线的颜色应符合设计规左，并设置黄/绿标志。Colorofearthingwireshouldconformtodesignregulationsandsetyellow-greensign.盘(箱)、柜内的接地汇流排，应使用铜材，并由绝缘支架固宦。接地总干线与接地体之间应承受焊接。Connectionlineforearthingsystemshouldapplywithcopper-coreinsulatedcableorwireandfastenoncopperboltandnut.Earthingbusbarinsideinstrumentpanel(box)orcabinetshallbemadeofcopperandbefixedbyinsulatedsupport・Applyweldingbetweenearthingmainlineandearthingpole・自己制作接地汇流排时，连接螺栓与汇流排之间的连接宜承受在汇流排上攻丝的方式连接。Whenfabricateearthingbusbarbyourselves,connectboltwithbusbarbytappingthread・保护接地SafeguardEarthing:正常不带电的金属局部，由于绝缘破坏而有可能带危急电压者，均应做保护接地。24V的就地仪表、开关等，设计无特别要求时，可不做保护接地。Allnotelectriferousmetallicpartsinnormalcondition.suchasshellofusage-powerinstruments,instrumentpanel,cabinet,box,caseandcabletray,conduit,supportfoundationetc.,shouldbeperformedsafeguardearthingiftheirinsulationlayershavebeendamagedandmayhavedangerousvoltage・Whendesigndoesnotrequire,safeguardearthingforlocalinstrument,switch.etc.,whosesupplypowerisnomorethan24V.canbeignored.在非爆炸危急场所的金属盘、板上安装的按钮、信号灯、继电器等小型低压电器的金属外壳，当与已接地的金属盘、板接触良好时，可不做保护接地。Alllowvoltageelectricaldevicesinsmallsize,suchaspushbutton,signallight,relayetc.,fixedonmetalpanelandboardinnon-explosionarea,iftheirconnectionwithgroundedmetallicpanelorboardisingoodcondition,theirsafeguardearthingcanbeignored・牢靠，不应串联接地。Safeguardearthingsystemcanconnecttosafeguardearthingnetforelectricengineeringlowvoltageplantsandensureconnectionreliableandhard・However,forbidexecutingserialearthing・在建筑物上安装的汇线槽及电缆保护管，当设计文件无只能一点接地的规泄时，可多点接地。Forcableductandprotectivepipeerectedontobuilding,ifdesignfilesdonotrequireonlyone-pointearthing,multi-pointearthingisavailable.信号回路接地：SignalLoopEarthing:5.3」信号回路的接地点应在显示仪表侧，当承受接地型热电偶和检测元件已接地的仪表时，不应再在显示仪表侧接地。Signalloopearthingshouldbeperformedatthesideofdisplayinstrument.Ifusingwell-groundedthermocoupleormeasuringelementsofinstrumenthavebeenearthed,earthingatthesideofdisplayisunnecessary.%仪表回路和系统只应有一个信号回路接地点除非使用隔离器将两个接地点之间的直、流信号回路隔离开。Everyinstrumentsignalloopandsystemshouldhaveonlyone-pointearthingingeneral,exceptthatusingseparatortosegregateDCsignalloopbetweentwoearthingpoints.书等厂商技术文件的要求接地Forinstiumentssuchassolenoidflowmeter,turbineflowmeterandanalyzingelements,carryoutearthingaccordingtoinstallationoroperationinstnictionandmanufacture”steclmiquefiles.信号回路接地可与屏蔽接地共用一个单独的接在系统。Signalloopearthingandshieldearthingcanshareasingleearthingsystem.4屏蔽接地：ShieldEarthing:屏蔽电缆〔线〕屏蔽层的接地应在显示仪表侧，同一线路的屏蔽层应具有牢靠的电气连续性，且只能一点接地。Performshieldearthingforshieldedcableatsideofdisplayinstrument.Forthesameconduit,ensureshieldhasreliableelectriccontinuityandearthatone-point.电缆屏蔽层在仪表盘和接线箱接线时，其屏蔽层应用绝缘保护套保护，不得与盘体或箱体接触。Whenperformingconnectioninsideofinstrumentpanelorjunctionbox,shieldshouldbeprotectedwithinsulatedsheathtopreventittouchpanelorbox・屏蔽电缆电缆头制作时，假设不需将屏蔽引出，应将屏蔽层与电缆护套切断，假设需要将屏蔽引出，网状屏蔽应套绝缘管，绝缘管端包在电缆头内，纸状屏蔽应焊接引线。Whilemakingcableterminal,ifitisunnecessarytofetchouttheshield,cutoffshieldlayerfromcablesheath・Ifnecessarytofetchoutshield,fornet-shapedshield,housinginsulatedtubeandwrappingitsendintocableterminal;forpapyraceousshield,weldingwireisrequired・mm2。Wirecross-sectionareaforshieldearthingshallbenolessthan1.5mm当多根屏蔽电缆固左在一起且均需要接地时，向汇流排引线应均匀分布在汇流排全部的连接点上。Whenmanyshieldedcablesarebandedtogetherandallneedearthing,connectthemequallytojointpositionofbusba匚本安系统接地：EarthingforIntrinsicallySafeSystem:本质安全线路本身不接地，但仪表功能要求接地时，应按仪表安装使用说明书和设计要求接地。Intrinsicallysafecirc