阻止某种功能的识别或执行.The prevention of a function from being recognized or acted upon.双D阀杆结构: 非常适用于连接操作手柄或执行机构.Double D Stem Configuration: Gives positive attachment for handles or actuators.手动或执行机构推动摇杆使扇形闸板沿轴心旋转开启,物料随即下落.Push r...