1、 Development and Evolution of Electric Control Valves
Early (early 20th century): relying on manual or simple electric devices, with low accuracy and slow response, only used for basic flow control.
Mid term (mid to late 20th century): Integrated electronic controller, added displacement feedback function, improved accuracy, adaptable to simple automation systems (such as industrial pipeline temperature control).
Modern (since the 21st century): intelligent upgrade, support for digital communication (such as 485, Internet of Things protocol), real-time monitoring of pressure/flow, adaptation to industrial Internet, and realization of remote control and fault self diagnosis.
2、 Core working principle
The core logic is "signal → drive → regulation":

Received signal: The controller (such as PLC, thermostat) sends an electrical signal (commonly 4-20mA or digital signal) to inform the target adjustment requirement (such as "open the valve by 10%").
Drive execution: After receiving signals, the electric actuator (motor+reduction mechanism) drives the valve stem to rotate/move in a straight line.
Valve regulation: The valve stem drives the valve core to move, changing the flow area between the valve core and the valve seat, thereby controlling the flow rate, pressure, or temperature of the medium (water, gas, oil, etc.) to achieve stable target parameters.
Feedback loop: Some models come with position sensors that provide feedback on the actual valve opening to the controller, correcting deviations and ensuring precise adjustment.