Regulating valve flow characteristic selection is appropriate and is directly related to the performance of the control valve work, first control valve selection should be based on the characteristics and requirements of the process medium, select regulate the flow characteristics of the valve spool. The so-called flow control valve means characteristics regulated medium flow ratio between the relative flow through the valve spool relative opening of the valve between. Depending on the shape of the spool valve, control valve flow characteristics are divided into linear, equal percentage and quick opening three properties. Since the percentage of the general condition of the control valve and other flow characteristics can adapt to changes in the larger case load, it is often preferred to use. For example, when used for hot water heater control, system piping resistance is large or big variations in system load when the percentage flow characteristics should be selected; if control before and after the steam heater or a certain pressure valves or Smaller load change conditions, you should choose linear flow characteristics. 

keywords: Regulating valve, control valve selection,