Regulators play an important role in the automatic control of modern plants, and the production of these plants depends on the proper distribution and control of the flowing media. These controls, whether energy exchange, pressure reduction, or simple container feeding, require some final control components to complete.
The regulating valve acts as a variable resistance in the pipe. It changes the turbulence of the process fluid or provides a pressure drop in laminar flow conditions caused by changing valve resistance or "friction." This pressure reduction process is often referred to as "throttle." For a gas, it is close to an isothermal adiabatic state, and the deviation depends on the non-ideality of the gas (Joule-Thomson effect). In the case of liquids, the pressure is consumed by turbulence or viscous friction, both of which convert the pressure into heat, resulting in a slight increase in temperature.
A common control loop consists of three main parts. The first part is the sensitive component, which is usually a transmitter. It is a device that can be used to measure the parameters of a process being adjusted, such as pressure, level or temperature. The output of the transmitter is sent to the regulating instrument, the regulator, which determines and measures the deviation between the setpoint or desired value and the actual value of the process parameter, and sends the correction signal one after the other to the final control element - adjustment valve. The valve changes the flow of the fluid so that the process parameters reach the desired value.
The regulating valve belongs to the series of control valves. The main function is to adjust the pressure, flow, temperature and other parameters of the medium, which is the final control component in the process loop.