Self-reliance type pressure before the valve pressure control principle of pneumatic control valve

Self-reliance type pressure pneumatic - valve working medium in front of the valve pressure P1 after throttling after the valve core, valve seat, a valve after pressure P2. At the same time P1 input through the control line to the actuator in particular of the membrane on the indoor function of force and reacting force of spring balance, determines the position of the valve core and valve seat, valve pressure before. When the valve after pressure P1 increases, the P1 role in particular of force also will increase. In particular reaction force is greater than the spring, the valve core to move off the seat until a particular reaction and the reaction force of spring balance. At this point, the valve core and valve seat of the circulation area of big, smaller flow resistance, thus make P1 to set value. Similarly, when the valve after pressure P1 reduce direction contrary to the above, this is self-reliance type ( Before the valve) The working principle of pneumatic pressure regulator.