Author Q&A: Fluid Mechanics of Control Valves: How Valves Control Your Process

ISA recently published Fluid Mechanics of Control Valves: How Valves Control Your Process by Hans D. Baumann, Ph.D., PE — a world-renowned expert on control valve technology who is credited with more than 100 patents relating to control valves. In this Q&A feature, Baumann highlights the focus, importance, and differentiating qualities of the book.

Note: A brief author biography is included at the bottom of this page. 

How would you describe the book?

It’s an up-to-date work on control valves that presents theoretical and practical information in an easy, conversational style, making it an excellent reference for experienced instrument and process engineers as well as for students.

The book begins with a basic explanation of the function and purpose of control valves, explaining the various types of valves that are available along with their features and limitations. It also serves as a valuable best practice guide, providing: 

• Directions for selecting the best valve for a given service and flow characteristics
• Simplified equations for sizing control valves for liquids and gases under normal and special conditions, such as flashing and laminar flow
• Guidelines for minimizing environmental problems, such as noise produced by turbulent or cavitating fluids and aerodynamic noise
• Solutions to dynamic instability problems 
• Methods for improving control loop stability
• A discussion on related safety issues such as “fail-safe” action and cybersecurity

What makes this book different than other books on the subject? What differentiates it?

As of today, there are no significant, up-to-date publications on control valves. Technology has progressed since the last publication of my books, and new knowledge has been gained in the areas of fluid mechanics and acoustics relating to control valves.

Extensive coverage of undesirable phenomena, such as liquid cavitation or excessive noise, is given together with equations on how to predict and how to avoid such occurrences. All technical information and equations are given in metric units beside the common US units, recognizing the international audience of control valve users. Examples are given in either system for ease of understanding the subject matter.

What types of automation professionals would benefit most by reading the book…and why?

The book is primarily targeted to instrument engineers needing fundamental knowledge about control valves and their role in industrial process control systems. This book should help engineers developing new control valves avoid in their design adverse or destructive effects, such as cavitation or excessive sound levels. The book is also a valuable technical guide when used at colleges teaching automatic control theory and for refresher instruction.

What makes it such an excellent reference manual? What makes the reference tables so valuable?

Reference tables are included to inform the person trying to select the correct size and type of control valve for a given service. As an example, the valve might need to be composed of stainless steel if the tables indicate the fluid to be controlled is corrosive.

The book also includes equations for sizing valves for all common types of liquids or gaseous fluids, including those for laminar fluid flow. The tables also provide vital information on valve materials, temperature ratings, and valve dimensions. Sizing information is especially helpful for sales representatives as it enables them to make the correct offering for a given valve specification.

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Meet the Author

Hans D. Baumann, is a world-renowned expert on control valves. He is credited with more than 100 US patents relating to valve control technology and has written eight books (among them the Control Valve Primer) on the subject. He is: an Honorary Member of ISA, ASME, the Fluid Controls Institute, and the Spanish Chemical Engineering Society; a member of Sigma Xi; and an inductee of the Automation Control Hall of Fame. For many years, he represented the US at the IEC International Standards Committee on control valves.

In 1977, he founded H. D. Baumann Assoc., Ltd., a manufacturer of control valves. The company was initially acquired by Fisher Instruments, and is now part of Emerson Process Management. Over his career, Dr. Baumann has served in numerous positions, including Chief Engineer (at W. & T. Co., a German valve supplier); Manager of Research & Development (at Worthington S/A in France); Director of Engineering (at Cashco); Vice President (at Masoneilan International, Inc.); and Senior Vice President of Technology (at Fisher Controls).

Dr. Baumann holds degrees from Case institute of Technology (now part of Case Western Reserve University) and Northeastern University, and earned a doctorate degree in mechanical engineering from Columbia Pacific University.