Preface The preparation of an international reference book such as this could not possibly be achieved without the total cooperation of so many individual authors and the back- ing of their various employers, especially where company contributions have been made, bringing together a wealth of professional knowledge and expertise. An acknowledgement such as this can only scratch the surface and cannot really portray the grateful thanks I wish to express to all these people concerned that have devoted so much time and effort to place their ideas and contributions to this Plant Engineering Handbook. Plant engineering is such a broad subject incorporating a multitude of disciplines and a wide variety of solutions to virtually every problem or situation, unlike some sub- jects that have clear-cut methods. In compiling the initial suggested guidelines for each of the contributions, I posed the questions to myself what information and assistance had I found difficult to locate during over 30 years as a plant engineer responsible for plants throughout the world and how could it be best pre- sented to assist others in their profession. I would therefore like to take this opportunity to thank each of the contributing authors for their patience and assistance in helping me to structure this publication. R. Keith Mobley President and CEO The Plant Performance Group Knoxville, Tennessee, USA