Azbil Yamatake smart valve positioner,pneumatic valve positioner for control valve AVP300-RSD3A

product description

The 300 Series receives a DC current signal from control devices and controls pneumatic valves. In addition to this basic function, the 300 Series has communication capabilities, automatic configuration program, and self diagnostics functions that will greatly increase productivity and the efficiency of plant operation. The model AVP301 has a valve travel transmitter function which transmits a 4-20 mA DC signal. The model AVP302 has a HART communication protocol.

specification

Yamatake valve positioner working principle:
Yamatake valve positioner is the main control valve accessories, it will stem the displacement feedback signal as the input signals, as set in the controller output signal, comparing, when there is deviation, change of its output signal to the actuator, the actuator movement, the valve stem is established between the displacement and the controller output signal to corresponding relation. Therefore, the valve positioner consists of a feedback control system with stem displacement as the measurement signal and controller output as the setting signal. The control variable of the control system is the output signal of the valve positioner to the actuator.

① It is used for the important regulating system with high quality requirements to improve the positioning accuracy and reliability of the regulating valve.
②  for both ends of the valve pressure difference (4p> 1MPa). The output force of the actuator is increased by increasing the pressure of the gas source to overcome the unbalanced force of the liquid on the spool and reduce the stroke error.
③  when the medium is adjusted for high temperature, high pressure, low temperature, toxic, flammable, explosive, in order to prevent external leakage, often the packing is pressed very tightly, so the friction between the stem and the packing is large, at this time the positioner can overcome the time delay.
④ the medium is adjusted for viscous fluid or containing solid suspended solids, the positioner can overcome the resistance of the medium to the stem movement.
⑤ for large diameter (Dg> 100mm) control valve to increase the output thrust of the actuator.
⑥  when the distance between the regulator and the actuator is more than 60m, the positioner can overcome the transmission lag of the control signal and improve the reaction speed of the valve.
⑦ to improve the meteor characteristics of the regulating valve.
⑧ when a regulator controls two actuators to implement range control, two positioners can be used to accept low input signals and high input signals respectively, then one actuator low range action, the other elevation action, which constitutes range regulation.