The working principle and structure of the pneumatic valve positioner

pneumatic valve positioner is one of the key accessories pneumatic regulating pneumatic valve, its effect is adjusting device of the output electric signal into actuating gas signal of pneumatic valve action. It has pneumatic valve positioning function, is to overcome the friction of pneumatic valve stem, and can be overcome by medium pressure changes caused by the unbalanced force, so that they can make the pneumatic valve quickly followed, and corresponds to the regulator output control signal, realizing fast positioning, adjust the pneumatic valve to improve the quality of its regulation. With the development of intelligent instrument technology, microelectronics technology is widely used in traditional instrument, greatly improve the function and performance of the instrument. http://www。 zgbfw。 com/info/
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pneumatic valve positioner ( FIG. http://www. zgbfw。 com/info/
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the principle of the pneumatic valve positioner: feedback pole pneumatic valve opening position change, when the input signal is produced by the electromagnetic torque and locator equals the torque feedback system, the locator force balance system in balance, the locator is in stable condition, the input signal and a corresponding proportion relationship with pneumatic valve position. When the input signal changes or changes, such as dielectric fluid forces force balance system balance is broken, magnetoelectric component force and feedback loop caused by pneumatic valve stem position changes of forces in a state of imbalance, because of the nozzle and the baffle, the positioner output air pressure changes, the change of the air chamber pressure actuator drive actuator movement, the pneumatic valve stem position to the new location, to correspond to the input signal, and reached a new equilibrium. In the use of changing the structure of the locator feedback pole ( Such as CAM curve, can change the adjustment of the pneumatic valve is, reaction, flow characteristic and so on, to adjust the pneumatic valve performance boost.
smart pneumatic valve positioner structure as shown in the figure below, the dotted line for the locator section, on the right side for pneumatic actuators. Control and drive circuit, as well as the position feedback sensor data acquisition circuit, the circuit board are located within the locator. Control circuit mainly complete control signal and the position feedback signal data acquisition and processing, at the same time to form stable output voltage. Drive circuit used in PWM current filter after the power amplifier. Nozzle baffle, the nozzle and the corresponding components make up the I/P converter, electric conversion. Adjust the nozzle baffle and nozzle spacing, through gas amplifier, complete the regulation of the output gas. Feedback and position feedback sensor, complete actuator displacement detection, and form a complete closed loop control system. http://www。 zgbfw。 com/info/
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smart pneumatic valve positioner structure ( FIG.
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