Pneumatic valve is classified according to the connection method

（ ） Threaded connections: pneumatic valve pneumatic valve body with internal thread or external thread, connected to the pipe threads.
　　（ ） Flange connection of pneumatic valves, pneumatic valve with flange, and the pipe flange connection.
　　（ ） Welding connection: pneumatic valve pneumatic valve body with the welding groove, connected to the pipe welding.
　　（ ） Clamp connect pneumatic valve, pneumatic valve body with a clip, connected to the pipe clip.
　　（ ） Card card set of connection: pneumatic valve and pipeline in a set of connection.
　　（ ） Pneumatic valve connected to the clamp: bolts directly to the pneumatic valve and the connection forms of two pipe clamp wear together.