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How do Temperature Controllers work?
A temperature controller gets input from temperature sensor such as a thermocouple or RTD.
It compares the actual temperature to the desired control temperature, or set point,and provides an output in the form of transistor output or relay
Control Valve – Theory & Sizing
The control valve, commonly named the final control element of control contains a pneumatic device that converts the control signal from the controller in action, regulating the process fluid flow.
Valves make up approximately 15% of the total expenditure for the materials and equipments for the refinery or chemical processing industry.
Valves are used to handle variety of liquids , gases , steam, air etc.