For seasoned chemical processing professionals, it's sometimes hard to realize that newcomers to the industry aren't as well versed in the tools of the trade. That's why AIChE offers a series of tutorials, workshops and educational sessions at the Chem Show designed to help those in the CPI perform their jobs more effectively.
One such session focused on valves, actuators & controllers. The session, presented by Valve Manufacturers Association (VMA), was lead by Greg Johnson, chairman, VMA Education & Training Committee, and president of Houston-based United Valve; Leon Brooks, vice chairman, VMA Education & Training Committee, and director of international sales at Cameron Valves & Measurement, Houston; and Paul Souza, VMA Education & Training Committee, and senior quality manager, AUMA Actuators, Canonsburg, Pa.
More than a dozen attendees gathered in the classroom to learn about standards, ratings and testing as well as about materials and components. The course began with an overview of valves. Presenter Greg Johnson noted that the Romans made the first valve in 25 AD. They were primarily used in domestic plumbing systems. Chemical analysis of these ancient valves is very close to today's ASTM B61 and B62 bronzes.
From the basics of what a valve is for – isolating, controlling and checking flow – to defining WOG (Water, Oil and Gas) ratings, which refer to the rating of the valve at ambient temperature, to operational factors and environmental considerations of actuator selection, the introductory course covered a lot of ground in three hours.
In addition to operational and environmental considerations for actuators, course instructors urged attendees to also think about valve actions, force and torque, available power sources, control, valve/actuator interface, installation and space requirements, and cost.
Another useful talking point noted that pressure-containing parts are probably the most important in regard to a catastrophic failure standpoint. According to course notes, the shell components of the valve must be of the correct material to ensure they will handle the media and pressure. Correct body material selection can be made by answering the following questions:
1. What is the operating pressure?
2. What is the operating temperature?
3. Is the fluid corrosive?
4. Is the fluid erosive?
Questions 1 and 2 are answered by referencing American Society of Mechanical Engineers (ASME) document B16.34 and checking the material/pressure/temperature charts. Questions 3 and 4 need to be answered by a design engineer with information on the fluid to be contained.
Traci Purdum is Chemical Processing's senior digital editor. She reported this story from the 2011 Chem Show in New York. She also enjoyed a great meal at Gordon Ramsay's Maze restaurant the night before. You can e-mail her at email@example.com.