We consider pressure control a fundamental control technique. Pressure controls are used in all types of applications:
There are several types of pressure control.
In simple pressure control, you typically are simply detecting if there is pressure or no pressure. Although this type of control is very easy and simple to implement, it is not able to maintain a setpoint pressure in the line.
In proportional control typically the tank pressure is an analog signal that accurately indicates the current pressure in the pipe. The controller is typically a PID controller that controls an analog output based on the current pressure and the setpoint. For example, if you want a pipe to maintain a pressure of 120 psi, you would get an accurate pressure transducer, scale the pressure transducer output to your units and then feed that pressure to the PID controller. The PID controller would then control a valve or pump to maintain the pressure. You can often maintain very tight pressure control using proportional control.
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