Feedback control loop fundamentals, PID control and what each of the three terms actually corrects, cascade control for handling a slower primary variable through a faster inner loop, and control valve sizing basics.
A plant with hundreds of flows, levels, pressures, and temperatures to hold steady cannot be run by manual adjustment — automatic feedback control is what makes a modern chemical plant operable at all. This module builds the feedback loop from its four elements up through the PID algorithm nearly every controller in a plant runs, the cascade architecture used when one loop's output needs to be constrained by a faster inner measurement, and the valve-sizing judgment calls that determine whether the final control element can actually deliver what the controller asks for.
By the end of this module you should be able to explain why a proportional-only controller settles with permanent offset, why an oversized control valve is a control-quality problem and not just an inefficiency, and how a cascade loop lets a fast inner controller reject disturbances before they ever reach the slower, more important outer variable — the same measurement-to-action chain Module 11's instrumentation content feeds directly into.