進(jìn)口自力式調(diào)節(jié)閥的選用
閱讀：1453發(fā)布時(shí)間：2012-5-24
進(jìn)口自力式壓力調(diào)節(jié)閥因?yàn)椴恍枰渌鈦?lái)能源如電源、氣源，僅靠介質(zhì)自身的能量來(lái)驅(qū)動(dòng)，既節(jié)能又環(huán)保，使用方便，安裝完畢后設(shè)定好壓力值即可投入自動(dòng)運(yùn)行，所以在對(duì)控制精度要求不高，又缺乏電源、氣源的場(chǎng)合，得到了越來(lái)越廣泛的使用。美國(guó)威盾VTON主要有用于調(diào)節(jié)流量的進(jìn)口自力式流量調(diào)節(jié)閥，用于調(diào)節(jié)溫度的進(jìn)口自力式溫度調(diào)節(jié)閥，用于控制壓力的進(jìn)口自力式壓力調(diào)節(jié)閥，
不過(guò)，這種閥門也需正確選型和正確安裝、使用，才能保證投入運(yùn)行后不出現(xiàn)什么問(wèn)題。選型方面就不用多說(shuō)了，比如調(diào)節(jié)閥是用來(lái)控制閥前壓力（控制閥前壓力調(diào)節(jié)閥）閥后壓力（控制閥前壓后調(diào)節(jié)閥），介質(zhì)是常溫還是高溫，有無(wú)腐蝕性，zui高工作壓力等等，一定要事先搞清楚，我們主要談?wù)劙惭b使用方面的問(wèn)題。因?yàn)槲襷ui近碰到一例自力式壓力調(diào)節(jié)閥的使用方面出現(xiàn)的問(wèn)題，很有代表性。閥門是用在蒸汽管道上的，投入使用才短短一兩個(gè)月，用戶就報(bào)修。到現(xiàn)場(chǎng)一看，大量蒸汽從調(diào)節(jié)閥膜頭的排氣孔中排出，噪聲極大，聲勢(shì)驚人。事故原因，明顯是蒸汽沒(méi)經(jīng)過(guò)冷凝，直接進(jìn)入膜頭，燒壞了膜片。用于蒸汽管道的自力式壓力調(diào)節(jié)閥，安裝時(shí)必須在執(zhí)行器和管道之間加一個(gè)冷凝罐，不能讓蒸汽進(jìn)入執(zhí)行器膜頭，而且，調(diào)節(jié)閥必須頭朝下安裝，冷凝罐要高于膜頭，初次使用，一定要將冷凝罐和膜頭中加滿水?？船F(xiàn)場(chǎng)的安裝方式，詢問(wèn)現(xiàn)場(chǎng)儀表人員，這些都沒(méi)問(wèn)題，那么是什么造成的呢？令人百思不得其解。后來(lái)，仔細(xì)詢問(wèn)了一個(gè)操作工，無(wú)意之下得知：這臺(tái)閥門安裝、投入使用后，冷凝罐和膜頭之間的銅管接頭一直在斷斷續(xù)續(xù)地漏水。原來(lái)是這樣，漏水導(dǎo)致冷凝罐里的水慢慢漏光，蒸汽就進(jìn)入膜頭，燒壞了膜片。由此可見(jiàn)，自力式壓力調(diào)節(jié)閥在蒸汽管道上使用時(shí)，安裝、維護(hù)方面一定要多加注意，為保證調(diào)節(jié)閥正常運(yùn)行，千萬(wàn)不能讓接頭漏水，不能讓冷凝罐缺水，要定期檢查，適時(shí)加水。其實(shí)，不光是自力式壓力調(diào)節(jié)閥，就是其它的自力式調(diào)節(jié)閥，在使用時(shí)也需注意維護(hù)和保養(yǎng)才行。另外，蒸汽壓力如果較高，選用活塞式執(zhí)行器，而不取薄膜式執(zhí)行器，因?yàn)槟て话隳艹惺艿膲毫Σ怀^(guò)0.4Mpa，過(guò)此雖然能用，卻要大大降低使用壽命。
尤其要提到的是當(dāng)要控制的壓力低于5kp的時(shí)候，要選用帶指揮器的自力式壓力調(diào)節(jié)閥，此閥門主要用于微壓的控制，氮封裝置場(chǎng)合。
Self-pressureregulatingvalveusedSelf-pressureregulatingvalvebecausethereisnootherexternalenergysourcessuchaspower,gassupply,relyingonthemedia'sownenergytodrive,bothenergysavingandenvironmentallyfriendly,easytouse,afterinstallationyoucanputpressurevaluesettorunautomatically,sointhecontrolaccuracyisnotrequired,thelackofpower,gassupplyoftheoccasion,hasbeenmorewidelyused.However,thisvalvealsoneedthecorrectselectionandproperinstallation,use,putintooperationtoensuretherearenoanyproblems.Needlesstosaytheselectionofareas,suchasthecontrolvalveisusedtocontrolvalvesorvalvebeforethepressureafterthepressuremediumisatroomtemperatureorhightemperature,withorwithoutresistance,themaximumworkingpressure,etc.,mustfirstfindout,wemainlydiscusstheaboutinstallationproblems.Irecentlycameacrossonecaseofself-pressureregulatingvalveusedinproblems,veryrepresentative.Valveisusedinthesteampipe,andputintouseuntilamonthortwo,theuserrepair.Tothesceneandsawalotofsteamcontrolvalvemembranefromtheventinthedischargehead,agreatnoise,momentumamazing.Causeoftheaccident,wasnotthroughthecondensationofsteamdirectlyintothemembranehead,burnthediaphragm.Self-pipingforsteampressurecontrolvalvemustbeinstalledbetweentheactuatorandpipeplusacondensationtank,cannotletthesteamintotheheadactuatormembrane,andthecontrolvalvemustbeinstalledupsidedown,condensatetankishigherthanfilmhead,initialuse,besuretoheadinthecondensatetankandfillthewaterfilm.Lookattheinstallationsite,askliveinstrumentationpersonnel,thesenoproblem,thenwhatiscausingit?Baffling.Later,askedindetailaboutanoperator,undertheintentionthat:thisvalveisinstalled,putintouse,condensatetanksandbrassfittingsbetweenthefirstfilmhasbeenleakingintermittently.Theoriginalisthecase,leadingtocondensationtankleakingslowlyleakedwater,steamentersthemembranefirst,burnthediaphragm.Thus,theself-pressureregulatingvalveusedinthesteampipe,installation,maintenancemustpaymoreattentiontoensurethenormaloperationofcontrolvalve,donotletjointleakage,condensationcannotallowwatertoregularinspection,timelyaddwater.Infact,notonlyistheself-pressureregulatingvalve,isthatotherself-regulatingvalve,wheninusealsoneedtopayattentiontomaintenanceandmaintenanceofthejob.Inaddition,ifahighervaporpressure,thebestselectionofpiston-typeactuator,ratherthantakethefilmactuator,becausethepressurediaphragmisgenerallynomorethan0.4Mpa,althoughthiscanbeusedtoo,havegreatlyreducedservicelife.
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