FT型投入式止回阀是钻柱内防喷器。当有井喷预兆，立即卸开方钻杆，将回压阀总成投入钻杆水眼内，开泵送下就位后就能达到防喷目的。该工具结构简单、操纵方便，只要卸开方钻杆的接头螺纹便可以投入钻杆的水眼内，就位后就能达到内防喷的目的。投入式止回阀由联顶接头和止回阀总成两部分构成。联顶接头与止动环用螺纹联接并上紧扣和钻柱连接下入井内，在未投入止回阀总成时，作为钻柱上的一个接头。Drop-inTypeCheckValve:Itisaninternalpreventer.Whenblowoutisgoingtohappen,thekellyrodshouldberemovedimmediatelyandthrowthebackpressurevalveassemblyintothewaterholeandthenpumpeddownwardtotherequiredplace.Thus,theblowoutcanbeprevented.Thevalvebodyconnectonthedrillingstem,Dropincheckvalveisaballandseaofhe***yduty,ifonlydropinthevalvecoreatthemouthofthewell,itturnintothevalvebody.投入式止回阀技术参数SpecificationofDrop－inTypeCheckValve型号Type止动环内径StopRingI.D.(mm)接头Joint止回阀总成CheckValveAssembly工作压力WorkingPressure(Mpa)连接螺纹Connection外径O.D(mm)内径I.D(mm)长度Length(mm)外径O.D(mm)内径I.D(mm)FT893089353353383570NC26FT105331053835036103570NC31FT121501215639554183570NC38FT159541596043558233570NC50FT168641687043568333570NC50FT1786417870515683335705-1/2FHFT2036420370620683335706-5/8REG)