Pneumatic control valve is a kind of control valve with simple structure, which can be matched with different accessories to achieve different functions. Valve positioner is one of the commonly used accessories. Next, we will briefly introduce how to adjust the positioner of the pneumatic control valve to achieve positive and negative effects and stroke adjustment.
The pneumatic control valve positioner has two functions: positive and negative. The input signal of the positive acting valve positioner will change from 20 to 100 KPa, and the change range of the output signal is the same as that of the input, while that of the reaction is just the opposite. When the valve positioner is used together with the pneumatic control valve, because the stroke of different pneumatic control valves is different, when the positioner outputs the same signal pressure to the control valve, the feedback amount given to the positioner by the action of different pneumatic control valves is also different. Therefore, it is necessary to install an adjustment device in the positioner, so that the feedback quantity fed back to the positioner can be consistent even if the travel is different and the displacement is different.
