ThedesignconfonnstoAPISpec6AandAPISpec16C.Ithasadjustablechockvalveandfixedchockvalveaccordingtostructure;Itcanbeendividedintomanualchockvalveandhydraulicchockvalveaccordingtooperationprinciple,andhalsocanbeenclassifiedintoneedlechockvalveandbarrelchockvalveaccordingtofunction.Theyareusedtoadjusttherateofoilandgas.controlthecasingpressureofchockandkillmanifold.Seatandvalvecoreismanufacturedbyhardalloywitiierosion-resistanceandwear-resistance.  ItemJLK(Y)AdjustableChockValveFixedChockValveRatedWorkingPressure2000psi～15000psiNominalBore2　1/16in.～4　1/16inProductSpecificationLevelPSL1-3MaterialClassAA～FFPerformanceRequirementLevelPR1-2TempsratureClass-29～121℃SpecificationmodelNominalBoreRatedWorkingPressure2000psi (14Mpa)3000psi (21Mpa)5000psi (35Mpa)10000psi (70Mpa)15000psi (105Mpa)21/16(52)★★★★★29/16(65)★★★★★31/16(78)———★★31/8(80)★★★——41/16(103)★★★★★Note:★forthisspecification

DFF型单流阀的设计符合API　Spec　16C规范要求，主要用于压井管汇，控制压井液或其它流体不能回流，以达到压井和其它作业的目的。

该系列产品主要规格有Φ52mm（21/16“）和Φ65mm（29/16”）两种规格，额定压力有14MPa、21Mpa、35MPa、60MPa等，其产品的特点是结构紧凑，操作方便、省力，其密封元件采用铁基硬质合金堆焊，密封可靠使用寿命长。

As one of leading products, diese series of products are designed and controlled according to API 6A and NACE MP0175.