LDK constant flow control valve is a new type of control valve that integrates pressure reducing valve and throttle valve, suitable for places such as water mixing, oil mixing, high-pressure water injection, and polymer injection. This valve can limit the flow rate to a predetermined value, and its automatic adjustment feature can keep the flow rate unchanged even when the pressure difference between the inlet and outlet changes. Principle

Assuming the inlet and outlet pressure of the control valve is P1, the pressure of the medium is reduced to P2 after passing through the pressure reducing valve port, and then through the throttle port of the throttle valve, the pressure decreases from P2 to P3. The pressure P2 and P3 before and after the throttle port of the throttle valve are respectively led to the two ends of the pressure reducing valve core. The hydraulic pressure generated by P2 and P3 on the pressure reducing valve core should be balanced with the spring force Ft of the pressure reducing valve and the moving force Fw generated by the indirect control volume of the medium flowing through the inlet and outlet of the pressure reducing valve, so that the pressure reducing valve is in a certain equilibrium position. When the pressure difference between the inlet and outlet of the control valve (P1-P3) changes due to changes in external load, the equilibrium position of the pressure reducing valve core will correspondingly change to maintain the balance. The front to back difference (P1-P3) of the throttle valve remains almost constant, thus maintaining a constant flow rate through the throttle at a given opening amount.

LDK constant flow control valve