网络优化资料：

The principle of pressure control at the rear of the valve.

In the working medium, the pressure P1 before the valve becomes the pressure P2 after the valve after being throttled by the valve core and valve seat. Through the control pipeline, P2 is input into the lower diaphragm chamber of the actuator to act on the top plate, and the force generated is balanced with the reaction force of the spring to determine the relative position of the valve core and valve seat, and control the pressure after the valve. As the pressure behind the valve increases, the force P2 acts on the top plate also increases.

At this time, the force of the top plate is greater than the reaction force of the spring, so that the flameproof solenoid valve core is closed to the position of the valve seat until the force of the top plate is balanced with the reaction force of the spring. At this time, the flow area of the valve core and the valve seat is reduced, and the flow resistance is increased, so that P2 is reduced to the set value. Similarly, when the pressure P2 after the valve decreases, the direction of action is opposite to the above, that is, the working principle of a self-operated (after valve) pressure regulating valve.

How the front door pressure control works.

In the working medium, the pressure P1 before the valve becomes the pressure P2 after the valve after being throttled by the valve core and valve seat. At the same time, P1 enters the upper membrane cavity of the actuator through the control pipeline to act on the top plate to generate a balanced spring reaction force to determine the relative position of the valve core and valve seat, and the plastic solenoid valve controls the front pressure of the valve. As the pressure P1 after the valve increases, the force acting on the top plate by P1 also increases.

At this time, the force of the top plate is greater than the reaction force of the spring, so that the valve core moves in the direction away from the valve seat until the force of the top plate and the reaction force of the spring reach a balance. At this time, the flow area of the valve core and the valve seat increases, and the flow resistance decreases, so that P1 is reduced to the set value. Similarly, when the pressure P1 after the valve drops, the direction of action is opposite to that described above, that is, the working principle of a self-operated (pre-valve) pressure regulating valve.