Flow control (process engineering)

Flow control regulates a fluid’s flow rate or direction through a system, typically by adjusting valves, pumps, or other flow devices.

Control valve: A valve that varies its opening to regulate fluid flow in response to a control signal. It is the most common final element for changing flow in a process loop.
Fluid mechanics: The study of fluids at rest and in motion, including the forces and energy governing their behavior. Its principles explain how pressure differences and resistance produce flow.
Mass flow controller: An instrument that measures and actively regulates the mass flow rate of a fluid. It provides compact, precise gas or liquid flow regulation in process equipment.
On-off control: A control method that switches an output between fully on and fully off rather than varying it continuously. It regulates average delivery differently from continuous modulation of flow.
Flowmeter: An instrument that measures a fluid’s volumetric or mass flow rate. Its measurement supplies feedback for correcting deviations from a target flow.
Continuity equation: A conservation relation stating that mass flow remains constant through a system without accumulation or sources. It connects flow rate to fluid density and pipe area.
Pump control: Methods for regulating a pump’s output by changing speed, displacement, or operating configuration. Variable-speed control can adjust flow without throttling it through a valve.
Throttle valve: A valve that controls flow by creating a variable restriction in a fluid passage. It is the throttling approach, contrasted with changing pump output to regulate flow.
PID controller: A feedback controller that combines proportional, integral, and derivative responses to reduce control error. It converts flow-measurement error into adjustments to a valve or pump.
Bernoulli's principle: A relation connecting pressure, speed, and elevation along ideal fluid flow. It explains how changing velocity or elevation affects pressure available for control.

Linked from 1 page

Flow separationNarrower topic: Separation management is a major aim of passive and active flow control.