FLOWX Engineer 86-21-54150349
Pneumatic actuators (mostly regulator) occupy an extremely important position in the industrial automation production, whose main parts are electric actuators and converter. The performances of these parts directly determine the pneumatic actuators application in winter.
Locator and converter are the main accessories and are used with pneumatic control valve to guarantee the regulator to position properly according to the set requirements, which also affects the pneumatic actuators application in winter. Electricity/gas valve is a converter that converts electrical signals into pressure signals, and is directly connected with pneumatic actuators by pneumatic positioner. Electricity/gas converter compares the feedback of output pressure value with initial value regulator and then adjusts the air pressure output according to the comparison of deviation to ensure pneumatic actuators application in winter.
Converters can also be directly connected with pneumatic actuators. Since the converter feedback is the output pressure value rather than the actual displacement value of valve, so when it is used alone and the unbalanced forces like valve stem friction force change, it can affect pneumatic actuators application in winter. Electricity/gas valve positioner is the actual valve position signal feedback, the pneumatic actuators control more accurate. The electric/gas conversion devices of both electric/gas valve converter and electric/gas valve positioned are the same.
As for the pneumatic actuators application in winter, the current is input into a coil, the core being magnetized. Under the effect of permanent magnetic field, the core with 0 as the axis of rotation and lever 1 balance spring is used to justify the initial baffle and nozzle distance to ensure that there is no current in coil, damper and nozzle interval optimum distance. When the input current makes the lever 2 have a counterclockwise rotation of small angle, the baffle will be near the nozzle and the pressure chamber pressure increases, pushing down the stem.
When the baffles are far away from the nozzle, and the chamber pressure is reduced, the effect of the negative feedback will ensure that the valve opening and the input signal is proportional to the relationship. In the early 1970s to 1980s, the using range of the locator in China accounted for about 85% ~ 90%. The defects of mechanical force balance structure are: poor environment resistance, being easily influenced by temperature, external vibration, the pneumatic actuators application in winter being not possible, being easy to wear and needing the time-consuming manual adjustment interrupting control loop. Although pneumatic actuators application in winter was impossible then, it is still in use by some traditional enterprises because of its low price.
Electronic electricity/gas valve positioner began to appear in the market in the early 1980s. The technology has been constantly updated in recent years and the new technology makes the pneumatic actuators application in winter possible. The control principle is quite different from the past mechanical force balance principle. The comparison of feedback given by value and the actual value is completely the comparison of pneumatic actuators, which is no longer to keep force balance and reduce the intermediate links as well as to eliminate some problems in the process of power transmission and transformation. The anti-interference ability being improved, so the pneumatic actuators application in winter becomes possible. The point of the pneumatic actuators application in winter provides users with a lot of convenience.