About ball valves: Ball is a sphere with a circular channel for disc, ball rotating with the stem of the valve action to achieve headstock. The headstock of ball valve is a perforated sphere, which rotates around axis that being perpendicular to the channel, so as to achieve the aim of opening and closing the channel. Ball valve is mainly used for opening and closing pipeline and equipment medium. 

Main advantages as follows: 
Suitable for frequent operation, with convenient headstock. 
1. Small fluid resistance. 
2. Simple structure, relatively small size, light weight, easy to maintenance. 
3. Excellent seal performance.
4. Not limited by the installation direction, the flow of medium can be arbitrary. 
5. No vibration, low noise. 

ball valves can be divided into: In terms of structure：floating ball valve, trunnion ball valve, elastic ball valve and oil sealing ball valve; In terms of channel: straight type, Angle type and three way type, etc., also, three way type can be classified into the t-shaped and l-shaped kinds. In terms of connection work: threaded, flanged and welded. 

Main shortcomings as follows: 
Ball valve installation and maintenance should be paid attention to following points: 
1. Make room for valve handle rotation. 
2. Cannot be used for throttling. 
3. Ball valves with belt transmission mechanism should be installed upright.