In the nearly 40 years since electronic control systems first became common features of industrial machines, controls theory has necessarily evolved to keep pace with machine design. Early on, systems ...

PID loops are a central component of modulating boiler control systems with applications ranging from basic steam header pressure control to cascading 3-element drum level control. A modern ...

Plant engineers and technicians are frequently asked to tune the controller when a control loop’s process value has prolonged or significant excursions from the set point. But in many instances, no ...

Equipment designers find that proportional control technology is ideal where precise performance is required in variable pressure or flow applications. Often perceived as more complicated than other ...

In process flow control, there are many factors affecting variability, but the greatest contributor is the control valve’s performance. Issues associated with control valves, such as dead band, ...

Compressible fluid flow through control valves will inevitably cause some form of flow-induced vibration in the fluid system. Identifying the type and cause of the vibration requires detective work.

A worksheet that calculates control valve installed gain can be part of any control valve selection process. For many years, the author has used, and promoted the use of, control valve installed flow ...