气动簿膜调节阀的特性误差较大 ,影响控制回路的调节效果 ,使调节品质变坏。产生特性误差的原因是 :阀杆存在摩擦力 ,影响阀芯的上、下压差 ,使阀门产生回程误差 ;另外 ,由于反馈机构连杆的弹性变形及存在间隙 ,及阀门定位器的转换与平衡机构的机械连接等原因 ,会存在回程误差。由于死区和回程误差的存在 ,使流量特性发生畸变 ,因而存在滞环特性。为了减小特性误差 ,应保持阀门动作的灵活性 ,减小阀门的自身阻力 ;另外 ,连杆机构应尽量短 ,以减小反馈杆的扭力矩 ;采用刚度大、不易挠曲的材料 ;采取加固反馈杆的方法来减小变形量 Pneumatic membrane valve characteristics of the larger error, the control loop affect the regulation effect, so that the quality of regulation worse. The reason for the characteristic error is that there is friction in the valve stem, which affects the upper and lower pressure difference of the valve core to make the valve produce return error. In addition, due to the elastic deformation of the connecting rod of the feedback mechanism and the gap and valve positioner conversion Balance mechanism mechanical connection and other reasons, there will be return error. Hysteresis characteristics exist because of the distorted flow characteristics due to the dead zone and return stroke error. In order to reduce the characteristic error, the flexibility of valve operation should be maintained to reduce the valve’s own resistance. In addition, the linkage mechanism should be as short as possible to reduce the torsional moment of the feedback rod. The material with high rigidity and not easily deflected should be adopted. Reinforcement of the lever method to reduce the amount of deformation