What is the filter pressure regulating valve used for? The reduced pressure. Pneumatic valve positioner is designed to work according to the principle of force balance, its working principle is designed and worked according to the principle of force balance. When going into the corrugated pipe pressure signal increases, the lever 2 turn around the fulcrum, dampers near the nozzle, the nozzle back pressure after the amplifier amplification, into thin film actuator air chamber, the stem moves down, and turns feedback pole (beam) around the fulcrum, feedback connection on the same shaft CAM (eccentric CAM) followed a counterclockwise rotation, through the roller to rotate the lever 1 around the pivot, and will feedback spring drawing, spring tension and pressure signal of lever 2 forces acting on the corrugated pipe reaches moment balance instrument to reach equilibrium. At this point, a certain signal pressure corresponds to a certain valve position. The above action mode is positive, if you want to change the action mode, as long as the CAM flip, A into B, etc., you can.
The so-called positive action locator, is the signal pressure increases, the output pressure also increases; Reaction locator, is the signal pressure increases, the output pressure decreases. As long as a positive action actuator is equipped with reaction positioner, the action of reaction actuator can be realized. On the contrary, as long as a reaction actuator is equipped with reaction positioner, it can realize the action of positive action actuator. Regulating valve is usually composed of electric actuator or pneumatic actuator and valve body. The direct stroke mainly has the straight single-seat type and the straight two-seat type, the latter has the circulation capacity is big, the unbalanced handle is small and the operation is stable characteristic, therefore usually is specially suitable for the occasion which the large flow rate, the high pressure drop and the leakage is little. Angle stroke is mainly: V-type electric regulating ball valve, electric butterfly valve, ventilation regulating valve, eccentric butterfly valve and so on.
