A typical control valve consists of a valve body, valve internal components, an actuator that provides drive for valve operation, and a variety of valve accessories. Valve accessories include positioners, transducers, supply pressure regulators, solenoid valves, dampers and limit switches.

1. Selection and application of control valves
The correct selection of control valves and whether to achieve the specified working conditions control requirements of the key, but also to ensure process safety. In order to meet the needs of the specified conditions, the selection of control valves need to take into account the type of valve body, the structure and material of the valve parts, the type of actuator and the safety factor and other elements, so that the selected control valve type is an optimal combination.

2. Control valve selection factors to be considered
To select the control valve suitable for the conditions, you need to comprehensively consider the impact of the control valve selection of a variety of operating conditions. The most important information including the control of the fluid type, fluid temperature, fluid viscosity, fluid specific gravity, maximum and minimum flow capacity, the maximum and minimum pressure of the valve inlet, the maximum and minimum pressure of the valve outlet, the pressure drop under normal flow conditions, the population and the outlet pipe calibre and wall thickness.

3. Control valve selection process
How to choose the right control valve to meet the application requirements of the conditions, control valve selection process at least need to consider the following process. Determine the conditions of work: including the valve population and outlet of the maximum differential pressure, maximum, minimum and normal operating conditions of the flow rate, fluid temperature and allowable noise. Calculate the required C-value, and determine the level of noise, cavitation and flashing by calculating the ℃-value). Selection of the type of valve internals: If the calculated noise value is greater than the limit allowed by the work environment, then the selection of noise-reducing valve internals should be considered. If the calculated cavitation or flash value of the valve in the specified work under the long-term use of a greater impact, it should be considered for the specified conditions of anti-cavitation and anti-flash valve components.