焊接与银钎焊SOLDERINGANDSILVERBRAZING

务必记住所推荐的阀门的用途是什么，并对所应用的环境进行分析，这样才能决定选用最适合安装什么样的阀门。在安装正确的阀门之前，为了防止损坏阀门，并保证充分发挥阀门的工作性能，请阅读一下安装指南：Analyzetheapplicationtodeterminewhichvalveisbestsuitedforinstallations,keepinginmindtheserviceforwhichthevalveisrecommended.Beforeinstallingthecorrectvalve,reviewtheinstallationinstructionstopreventdamagetothevalveandtoassureitsmaximumefficiency：

先沿着垂直方向切割管道，并修整、去除毛刺，测量管径。Cuttubeendsquare.Ream,burrandsize.

使用纱布或钢丝刷清除管道和切割部位，使其金属表面发光发亮。建议不要使用钢丝绒。Usesandclothorsteelwirebrushtocleanbothendstoabrightmetalfinish.Steelwoolisnotrecommended.

在管道的外面和焊接罩的内部涂上焊剂，焊剂必须完全覆盖焊接表面。请有节制地使用焊剂。Applyfluxtooutsideoftubeandinsideofsoldercup.Surfacestobejoinedmustbecompletelycovered.Usefluxsparingly.

要确保阀门处于开启状态。先对管道加热。尽可能多的将热从管道传递到阀门。避免延长阀门本身的加热时间。Besurethatvalveisfullyopen.Applyheattotubefirst.Transferasmuchheataspossiblethroughtubeintovalve.Avoidprolongedheatingofvalveitself.

银钎焊的方法：对需要进行钎焊的部件进行组装。如果允许涂上焊剂的部件处于直立状态，那么焊剂中的水分会蒸发掉，而干燥的焊剂很容易脱落，致使暴露的金属表面容易被氧化。在进行连接组装时，要将管道插入管套直到遇到阻挡为止。组装是要保证有稳固的支撑，使得整个钎焊操作过程中能够保持在直线位置。SilverBrazingMethod:Assemblepartstobebrazed.Iffluxedpartsareallowedtostand,thewaterinthefluxwillevaporate,anddriedfluxisliabletoflakeoff,exposingmetalsurfacestooxidation.Assemblejointbyinsertingtubeintosockethardagainstthestop.Theassemblyshouldbefirmlysupportedsothatitwillremaininalignmentduringthebrazingoperation.

注：对于1英寸或更大公称通径的阀门，一次性将连接部件加热到所需温度比较困难。为了在整个大面积上保持正常的温度，通常情况下需要两个焊枪。建议对整个管套区域进行适当的预热。建议采用乙炔火焰对连接部件进行加热。首先从离阀门1英寸的地方开始对管道进行加热，然后围绕着管道短距离上下交替对管道进行火焰烘烤，并以适当的角度旋转管道，避免烧穿管道。火焰要连续运动，不允许停留在某一点上。NOTE:Onone-inchandlargervalves,itisdifficulttobringthewholejointuptotemperatureatonetime.Itwillfrequentlybefounddesirabletouseadouble-tiptorchtomaintainthepropertemperatureoverthelargerarea.Amildpre-heatingofthewholesocketareaisrecommended.Applyheattopartstobejoined.Thepreferredmethodisbyoxy-acetyleneflame.Heattubefirst,beginningoneinchfromedgeofvalve.Sweepflamearoundtubeinshortstrokesupanddownatrightanglestorunoftube.Toavoidburningthroughtube,theflameshouldbeincontinuousmotionandnotallowedtoremainonanyonepoint.

在阀门的套筒底座用火焰进行烘烤。加热要均匀，用火焰对阀门及管道进行火焰烘烤的过程要延续到阀门上的焊剂不再发出声音。不要对阀门过度加热。Applyflametovalveatbaseofsocket.Heatuniformly,sweepingflamefromvalvetotubeuntilfluxonvalvebecomesquiet.Avoidexcessiveheatingofvalve.

当焊剂变成液态并且在管道和阀门上呈现半透明状态时，开始将火焰沿着连接部件的轴线进行进退烘烤，以保持连接部件、特别是阀门套筒底座部位的热度。Whenfluxappearsliquidandtransparentonbothtubeandvalve,startsweepingflamebackandforthalongaxisofjointtomaintainheatonpartstobejoined,especiallytowardbaseofvalvesocket.

使用适量的焊料：如果使用线状焊料，那么对公称通径为3/4英寸的阀门就要采用3/4英寸的焊料，等等。如果使用的焊料太多，那么有些焊料可能会流过管道阻挡部位，并堵塞密封区域。在安装连接部件时，可以看到焊料和钎焊合金继续流动Usejustenoughsolder:withwiresolder,use3/4"fora3/4"valve,etc.Iftoomuchsolderisused,itmayflowpasttubestopandclogsealingarea.Whenjointisfilled,acontinuousrunofsolderorbrazingalloywillbevisible.

银钎焊法：将焊线或焊杆点在阀门里的管道套座上。当焊杆或焊线进入连接处时要将火焰从其上面移开。当合金流进连接处时，要前后移动火焰。达到适当的温度后，合金将迅速容易地流进管道外壳和阀门套管之间的空间。连接处被充满后，就会看到焊接合金的边缘。SilverBrazingMethod:Applybrazingwireorrodatpointwheretubeentersvalvesocket.Keepflameawayfromrodorwireasitisfedintothejoint.Moveflamebackandforthasalloyisdrawnintojoint.Whenthepropertemperatureisreachedalloywillflowreadilyintospacebetweentubeouterwallandvalvesocket.Whenjointisfilled,acontinuousrimofbrazingalloywillbevisible.