A positioner is installed on a diaphragm type or cylinder type actuator to improve the operating characteristics of the control valve. The positioner drives the control valve, coping with the frictional resistance of gland packing and unbalanced force on the plug which prevent the movement of thy valve stem, till the valve travel corresponding to the input pneumatic signal (0,2 to 1,0 kgf/cm2) or input current signal (4 to 20 mA DC is attained. As for the features, the maximum supply air pressure is 7 kgf/cm2, and they can be used for both single action and double action actuators; they can be used for al1 pneumatic type actuators from general purpose diaphragm type to high output cylinder type.
| NS737 (pneu-pneu) | NS727 (elec-pneu) | |
| Input signal | 0.2 - 1.0 kgf/m2 | 4 - 20 mA DC (standard) |
| Supply air pressure | 1.4 - 7 kgf/m2 | |
| Actuator type | Suitable to both single action (spring return) and double action types | |
| Characteristics | Linear, or free choice with cam | |
| Split range | 30 - 100 % | 50 - 100 % |
| Direction of action | Direct action and reverse action. Direction of action can be reversed | |
| Input angle [lever type] | 5 - 30° | 10 - 30° |
| Input angle [cam type] | 60 - 120° | |
| Air consumption | 7 Nl/min (when supply pressure is 1.4 kgf/cm2 | |
| Outlet air flow rate | 70 Nl/min (when supply pressure is 1.4 kgf/cm2 | |
| Air input port | PT 1/4 NPT | |
| Explosionproof construction | - | Explosionproof construction d2G4 |
| Electric wire port | - | PT 1/2 female |
| Wiring system | - | Conduit tubing system, pressure tight packing |