How to understand the regulating the flow of pneumatic valve and characteristics

proper flow rate characteristics of pneumatic valves, pneumatic valve is directly related to the work of good or bad, should according to the characteristics of the process object, select the flow characteristic of pneumatic valve core. Adjust the flow rate characteristics of pneumatic valve is modulated medium flows through the relative flow of pneumatic valve and pneumatic valve of the relationship between the relative opening degree. According to the shape of the pneumatic valve core is different, mainly divided into straight line, such as percentage and quick opening three. In general, as a result of equal percentage flow characteristic of regulating pneumatic valve can adapt to load changes larger occasions, reason often preferred to choose. According to the characteristics of regulating object, consider regulating pneumatic valve flow characteristics and objects to cooperate, to improve the properties of the whole system is very important. Object, the change of the load, piping and control quality is to consider. Control, for example, or hot water heater pipe resistance significantly bigger or the system load changes, all persons to be percentage flow characteristic. If the control is a steam heater or pneumatic valve pressure difference before and after a certain or load change is small, then choose the linear flow characteristic.