What is the effective adjustment range of a butterfly valve?
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I would like to ask the experts here: what is approximately the effective adjustment range for opening angle of double-eccentric butterfly valves and triple-eccentric butterfly valves?
There should be a trend line for the flow rate of the fluid as a function of the opening degree of each valve. For an effective opening degree, ? ? ? It also follows this curve. For users, it’s best not to worry about these and adjust as needed.
Butterfly valves do not have very good control performance
Generally, a range of 10~90% is considered adjustable, though the adjustment performance at small and large openings is not very good. . . .
Generally speaking, valves serve a regulating function, but they lack precision.
85% for butterfly valves is basically the maximum value; it’s not very meaningful, as the performance isn’t as good as that of valves with guide vanes
It is mainly used because of impurities in the material; this type of valve is not intended for precision.
I happen to have a set of simulation diagrams for butterfly valves, which can serve as a reference for understanding the flow characteristics of these valves. 1. The curve graph shows 6 P-Q curves corresponding to different angles of rotation; from this graph it can be seen that: 1.1. For Line A, at the same pressure drop, a larger angle of rotation results in a higher flow rate. 1.2. For Line B, at the same flow rate, a smaller angle of rotation leads to a greater pressure drop. 2. The flow pattern diagram indicates that when the angle of rotation decreases to a certain level, vortices begin to form on the back side of the valve disc and their intensity increases. 3. The pressure drop diagram shows that when the angle of rotation decreases to a certain level, the pressure difference before and behind the valve disc increases significantly