In this installment of Ask The Experts, noted process control authority and CONTROL Columnist Béla Lipták and his cadre of automation experts answer a readers question regarding control valves for slurry services.
There are two main drivers for partial stroking of valves in safety systems: the desire to extend manual test intervals to as long as possible; and to reduce the amount of redundant hardware required for higher safety integrity levels. Like most things in life, it all boils down to one thing: trying to save money.
To make the most of diagnostic equipment used in chemical processing, technicians must stretch their knowledge of control valves and related diagnostic equipment that keeps tabs on valve health and safety.
Valves and actuators designed for handling radioactive waste must meet strict government requirements. This sometimes requires unconventional solutions. Such was the case at the Hanford Waste Treatment Project (WTP), Hanford, Wash.
When it comes to selecting and sizing control valves and positioners, this article not only helps you pick the right one for the right job, but also includes a valuable valve selection chart you can download!
The more energy prices rise, the more heat integration saves. However, heat integration steps can present complex control problems. Slip-ups in putting control systems in place can make operations nearly impossible. That certainly was the case at one unit using heat recovery.
Author: Andrew Sloley, contributing editor and Carolyn K. Hawley, VECO USA