Self-reliance type flow control structure and principle of pneumatic valve

self-reliance type flow control pneumatic valve in structure, is a combination of double pneumatic valve, pneumatic valve is controlled by a manual adjustment and automatic balance pneumatic valve groups. Manually adjust the action of the pneumatic valve group is set flow, automatic balance the role of the pneumatic valve group is to maintain constant flow.
for manually adjusting the pneumatic valve group, G = P - flow P type Kv for manual adjustment in the pneumatic valve pneumatic valve port flow coefficient, P - P for manual adjustment pneumatic valve pneumatic valve differential pressure on either side of the mouth. Kv depends on the size of the opening, the opening is fixed, the Kv is constant, so as long as the P - G P is kept constant, the flow is constant. The P - P constant is controlled by the automatic balance pneumatic valve group. Such as import and export of differential pressure P - P increases, by pressure sensitive film and the role of the spring balance of automatic pneumatic valve set down, P - P increases, thus keeping P - P is constant; On the other hand P - P decreases, and the automatic balance pneumatic valve set up, the P - P, P - maintained P is constant.
manually adjust the opening of pneumatic valve group of each corresponding to a flow, the relationship between the opening and flow by calibration test-bed experiment, with the opening of the show and locking device.