(1)Used in important regulating systems with high requirements for regulating quality to improve the positioning accuracy and reliability of regulating valves.
(2)Used in the occasion where the pressure difference between the two ends of the valve is large ( △p>1MPa). Increase the output force of the actuator by raising the pressure of the air source to overcome the unbalanced force generated by the liquid on the spool and reduce the travel error.
(3) When the regulated medium is high temperature, high pressure, low temperature, flammable, in order to prevent external leakage, the packing is often pressed very tightly, so the friction between the stem and the packing is large, and the time lag can be overcome with the positioner at this time.
(4)When the regulated medium is viscous fluid or contains solids in suspension, the positioner can overcome the resistance of the medium to the movement of the valve stem.
(5) Used for large-diameter (Dg>100mm) regulating valves to increase the output thrust of the actuator.
(6)When the distance between the regulator and the actuator is above 60m, the positioner can be used to overcome the transmission lag of the control signal and improve the action response speed of the valve.
(7) It is used to improve the flow characteristics of the regulating valve.
(8)When a regulator controls two actuators to implement split-range control, two positioners can be used to accept low input signal and high input signal respectively, then one actuator low range action and the other high range action, which constitutes a split-range regulation.
