The electrical valve positioner is the main accessory of the regulating valve. It is usually used with the pneumatic regulatory valve. It accepts the output signal of the regulator, and then use its output signal to control the pneumatic regulating valve.The mechanical device is fed back to the valve positioner, and the valve position is passed to the upper system through the electrical signal.
Electric valve positioner function
1. The electrical valve positioner is a regulatory system that requires high quality requirements. It needs to improve the positioning accuracy of the regulating valve and increase reliability.2. Installation is where the pressure difference between the valves is greater than 1MPa.By increasing the output force of the latter, the error of the fluid reduced the power of the fluid to the valve core.3. To avoid leakage, when the liquid fluid contains high temperature, high pressure, low temperature, toxic, flammable, explosive and other states, the filling is usually squeezed very strictly.Increase, then use the positioner to overcome the stagnation.
Electric valve positioner failure
Fault A: The electrical valve positioner has an input signal, but the output is very small or there is no (1) The positioner is tuned for the torque motor coil due to excessive tuning screw adjustment.(2) The internal wiring of the torque motor coil may be broken or burn out due to overcurrent; the measuring coil resistance is used with a multimeter, which should be about 250Ω when normal.
Principles of electrical valve positioner
The electrical valve positioner is the main accessory of the control valve. It uses the valve stem displacement signal as the feedback measurement signal for input, and the controller output signal is used as a set signal to compare.The output signal enables the execution mechanism to move the corresponding relationship between the valve rod position and the controller output signal.Therefore, the valve positioner composition uses the valve stem displacement as the measurement signal, and the controller output as the feedback control system for setting the signal.The manipulation variable of the control system is the output signal of the valve positioner to execute the mechanism.

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