Classify according to main parameters (I) Classify vacuum valves according to pressure. Valves whose working pressure is lower than standard atmospheric pressure. Low pressure valves with nominal pressure PN less than 1.6MPa. Medium pressure valve is a valve with a nominal pressure of PN 2.5~6.4 MPa. High pressure valve with nominal pressure of PN10.0~80.0MPa. Ultra high pressure valves with nominal pressure PN greater than 100MPa. 　　　　

Third, when selecting the appropriate pneumatic butterfly valve accessories, there must be a focus, which means the selection of key accessories. Positioner and converter are important accessories. The main function room of the positioner improves the speed of operation and the output force. Therefore, selecting the appropriate positioner is to select the appropriate motor, which is an important power source of machinery. Therefore, selection is very important. Another important accessory is the converter. For some dangerous places and controlling the operating speed, the converter, Therefore, it has a good auxiliary function for the positioner. Therefore, selecting the appropriate pneumatic butterfly valve accessories and grasping these skills will make it easier.