Manually adjustable flow control hydraulic valve NV08

Matters need attention

As the flow capacity decreases, the adjustable ratio of the valve will decrease. But at least it can be guaranteed to be between 10:l and 15:1. If the adjustable ratio is smaller, it will be difficult to adjust the flow.

When the valves are used in series, with the change of opening, the pressure difference between the front and back of the valves also changes, which makes the working characteristic curve of the valves deviate from the ideal characteristics. If the pipeline resistance is large, the linearity will become a quick opening characteristic, and the adjustment ability will be lost. Equal percentage characteristics will become straight line characteristics. Under the condition of small flow rate, because there is little pipeline resistance, the distortion of the above characteristics is not great, and the equivalent percentage characteristic is actually unnecessary. From the manufacturing point of view, when Cv =0.05 or less, it is impossible to produce equal percentage of side shapes. Therefore, the main problem for small flow valves is how to control the flow within the required range.

From the perspective of economic effect, users hope that a valve can be used for both interception and regulation, and it can be done. But for the regulating valve, it is mainly to control the flow, and closing is secondary. It is wrong to think that the flow of small flow valve itself is very small and it is easy to realize interception when it is closed. The leakage of small flow control valves is generally regulated abroad. When the Cv value is 10, the leakage of the valve is defined as 3.5 kg/cm. Under air pressure, the leakage is less than 1% of the maximum flow.