Equipment that adds no energy to the fluid — it manages it: directing, limiting, blocking, protecting and measuring the flow. In practice, control has an energy price — every throttling valve dissipates energy as head loss.
Families
- Valves — the blocking, regulating, protection and control element (ISO 14224 class VA). Includes self-actuated valves (pressure reducing/regulating) — "regulators" are not a separate family.
- Instrumentation — measures, transmits and commands: sensors/transmitters, control logic and fire & gas detection (their own control and safety classes in ISO 14224).
The typical control loop closes the cycle between the two families: the transmitter measures, the controller decides and the control valve — final element (IEC 60534) — acts on the process.