美国费希尔Fisher-POSI-SEAL®A41高性能蝶阀调节阀也叫做控制阀，在工业自动化过程控制领域中，通过接受调节控制单元输出的控制信号，借助动力操作去改变介质流量、压力、温度、液位等工艺参数的***终控制元件。一般由执行机构和阀门组成。如果按行程特点，调节阀可分为直行程和角行程；按其所配执行机构使用的动力，按其功能和特性分为线性特性，等百分比特性及抛物线特性三种。调节阀适用于空气、水、蒸汽、各种腐蚀性介质、泥浆、油品等介质Fisher®POSI-SEAL®A41（A41高性能调节蝶阀产品简介）：POSI-SEAL®A41isahigh-performancebutterflyfeaturingadoubleDshaftforon-offservice.A41is***ailableinNPS2through12,CL150andCL300.TheNPS2valveismulti-ratedtoCL150/300/600.A41alongwith1035RackandPinionActuatorispartofthePOSI-SEALPackage.FeaturesandBenefits:ExceptionalShutoff—Patentedbidirectionalsoftsealringwithpressure-assistingactionresultsinexceptionalshutoffratesasshowninthespecificati***.ShaftRetention—Redundantshaftretentionprovidesaddedprotection.Thepackingfollowerandshaftstepinteracttoholdtheshaftsecurelyinthevalvebody.EasyInstallation—Thevalvebodyself-centersonthelineflangeboltsasafast,accuratemeansofcenteringthevalveinthepipeline.SourServiceCapability—Materialsare***ailableforapplicati***handlingsourfluidsandgases.ThesematerialscomplywiththerequirementsofNACEMR0175-2002.ImprovedEnvironmentalCapabilities—TheoptionalENVIRO-SEAL®packingsystemisdesignedwithimprovedsealing,guiding,andloadingforcetran***ission.TheENVIRO-SEALpackingsystemcancontrolemissi***tobelowtheEPA(EnvironmentalProtectionAgency)limitof100ppm(partspermillion)forvalves.LowCostMaintenance—Inpidualdisc/shaftcomponentscanbereplacedafterdisassemblyduetosleeveandtaperpinconnecti***.)