Pneumatic valve is an important device in industrial pipeline system. It is based on the normal valve and equipped with pneumatic performer, which is run to work by pneumatic pressure. According to the working mode of valve, the pneumatic can be divided into straight route and angle route; According to performer, it can be divided into single effect and double effect. The pneumatic valve was cut down, connected and adjusted by outputting signal. Normally, the pneumatic valve all equip magnetic valve, pneumatic three connector, limit switch and locator etc.
Locator of pneumatic valve uses the theory of dynamic balance to work. When the pressure signal through corrugated pipe becomes bigger, the lever2 roll around the pivot. The back plate is close to the injector. The back pressure of injector was enlarged by enlarger and then be sent to film perform pneumatic room to make the valve lever move down and lead the feedback lever roll around the pivot. The feedback cam connected on the same axis also roll anticlockwise and lead the rolling of lever1 around pivot by gear. Then stretch the feedback spring, the pressure to lever2 from the spring and the signal pressure all effect on the corrugated pipe became moment balance and then the instrument became balance state. At this time, the certain signal pressure correspond to the certain valve position. The above action type is positive action. If we want to change the action type, just need to turn the cam to make the A direction to B direction. The positive locator means when the signal become larger, the output pressure is bigger. The negative locator means when the signal become larger, the output pressure is smaller.
