The Control valve consists of two main assemblies: the valve body assembly and the actuator assembly (or actuator system), which are divided into four series: single-seat series control valves, two-seat series control valves, sleeve series control valves and self-operated series control valves. The variants of the four types of valves can lead to a large number of different applicable structures, each with its own special applications, characteristics, advantages and disadvantages. Although some control valves have a wider range of application conditions than others, control valves are not suitable for all conditions to jointly build the best solution to enhance performance and reduce costs.