The advent in the 1950s, cast steel ball valve With the rapid development of science and technology,

continuous improvement of the production process and product structure, in just 40 years, it has 

rapidly developed into a main valve class.
 In the industrially developed countries of Western countries, the use of the ball valve is gradually on 

the increase in China, the ball is widely used in petroleum refining, long-distance pipeline, chemical, 

paper, pharmaceutical, water conservancy, electricity, municipal, and steel industries. occupies a 

pivotal position in the national economy. Ball valves only need to turn the operation of 90 degrees 

and a small torque can be closed tightly. Full equality body cavity of the media to provide a little 

resistance, through the flow channel. Usually considered the most suitable valve opening and 

closing done directly, but recent developments have sent the ball valve is designed so that it has 

a throttle and control the flow purposes. The main features of valve is its own compact, 

easy operation and maintenance, suitable for general working medium of water, solvents, acids, 

and natural gas, but also applies to the working conditions of media, such as oxygen, hydrogen 

peroxide, methane and ethylene. Ball valve can be a whole, it can be modular.Manually operated 

ball valves can be closed quickly and thus there is a danger of water hammer. Some ball valves are 

equipped with an actuator that may be pneumatically or motor operated. These valves can be

used either for on/off or flow control. A pneumatic flow control valve is also equipped with a 

positioner which transforms the control signal into actuator position and valve opening accordingly.