Control valves play a major role in the everyday effort to increase process plant profitability and conserve energy. Proper selection of these valves can have a significant financial impact on the overall cost of a project and how well the process can be controlled. To narrow down the choices, the engineer must understand how the general characteristics of each type of valve match up with the design requirements (Table 1). In addition to the types of valves shown in Table 1, many valve suppliers have their own proprietary valve designs, which are modifications of the five basic types in this table.
CEP Magazine (2002) Ease Control Valve Selection