1. Working condition analysis: First, clarify the use environment, including the properties of the medium (such as temperature, pressure, corrosiveness), flow range, regulation accuracy requirements and installation methods, which is the basis for selection.
2. Valve body material: Select the appropriate valve body material according to the characteristics of the medium, such as stainless steel for corrosive media, cast iron or plastic for water or other non-corrosive liquids.
3. Actuator type: Linear actuators are suitable for butterfly valves, ball valves, etc., while angular actuators are suitable for plug valves, gate valves, etc. It is also necessary to consider whether spring return (single acting) or continuous air supply (double acting) is required.
4. Control characteristics: Select linear, equal percentage or fast opening flow characteristics according to the needs of the control system to match different process control curves.
5. Accessory configuration: Consider whether accessories such as positioners, filter pressure reducing valves, solenoid valves, etc. are needed to improve regulation accuracy and system reliability.
6. Brand and service: Choosing a well-known brand of pneumatic control valves usually means better quality and after-sales service, which can save costs in the long run.