I want to use a proportional valve for controlling the pressure in a tank/cylinder. In our design we need to have two profiles for PC valve. The profiles have to be time based . One profile is to build the pressure from 0 bar to 50 bar and another to drop the pressure from 50 bar to 0 bar (see figure below). Profile is shown in attachment. The PC valve I am using is Reducing/Relieving valve. Does my design require a PID? . Any help is appreciated....