A control valve is the final control element in a process loop, offering a variable resistance to fluid flow that is manipulated to keep a process variable at its set point despite load disturbances; its behavior is characterized by an inherent flow-vs-stem-travel relationship (linear, equal-percentage, or quick-opening, set by plug shape) and quantified by a sizing coefficient CV relating flow rate to the pressure drop across the valve. This belongs to industrial process-control instrumentation, linking valve construction and characteristic curves to standardized (ISA) sizing equations used to select a valve for a given fluid, flow rate, and pressure-drop condition.
A control valve is the final control element in a process loop, offering a variable resistance to fluid flow that is manipulated to keep a process variable at its set point despite load disturbances;…