The flow characteristics of the electric control valve directly affect the control quality and stability of the system, so it needs to be selected correctly.
The flow characteristics of the electric control valve are divided into ideal flow characteristics and working flow characteristics. The flow characteristics provided by general manufacturers are ideal flow characteristics, while the actual application of electric control valves requires working flow characteristics. Since the pressure drop ratio S is less than 1, the operating flow characteristics are convex. Therefore, when selecting the flow characteristics of the electric control valve, the working flow characteristics should be considered first. Then, select the ideal flow characteristics according to the actual application. The ideal flow characteristics commonly used in production are linear, equal percentage and quick opening characteristics. The quick opening characteristic is mainly used for two-position control and program control. Therefore, the selection of the flow characteristic of the electric regulating valve usually refers to how to reasonably select the linear and equal percentage ideal flow characteristics.
When the electric control valve is actually used, the control valve is always installed in the process piping system, and the pressure difference between the electric control valve and the electric control valve changes with the resistance of the piping system. Therefore, when selecting the flow characteristics of the control valve, not only should it be based on the process characteristics, but also should be considered in conjunction with the piping conditions of the system.