Valve Positioner , mounted on a pneumatic actuator, moves the actuator by receiving Dc4 20mA signals from a controller, Also, the function of detecting and returning the actuator displacement provides accurate positioning In response to DC 4-20mAsignaIs.It can be used with both spring return and double acting actuators Pass CE authentication Pass explosion proof ( Exia II BT6,Exdm II BT6,Exdm II CT6) Authentication Pass Ip66 authentication High anti-vibration (none effective In 5-200 Hz) The linking of air duct is perforated form, convenient for the linking in all direction Convenient for the transform of positive action and counteraction 1/2spllt range available by simple adjustments without changing parts Easy maintenance Simple structure for feed back connection Economic energy saving