Ray Sinnott's varied career, mainly in design and development, began with several major companies including Dupont and John Brown. The main areas covered within these appointments were: Gas Production and Distribution, Nuclear Energy, Elastomers and Textile fibres. After his career in industry he joined the Chemical Engineering Department, University of Wales Swansea in 1970, specialising in teaching process and plant design, and other engineering practice subjects. The first edition of Chemical Engineering Design (Coulson and Richardson's Vol 6) was published in 1983. Subsequent editions have been published at approximately 5 year intervals.Ray Sinnott retired from full time teaching in 1995 but has maintained close contact with the engineering profession.Gavin Towler Ph.D. is the Vice President and Chief Technology Officer of UOP LLC, a Honeywell company. UOP is a leading supplier of catalysts, process technology, proprietary equipment and services to the oil, gas and petrochemical industries. In this capacity he is responsible for delivering process, catalyst and equipment innovations for UOP's four businesses.Gavin has 20 years of broad experience of process and product design and has 65 US patents. He is co-author of "Chemical Engineering Design, a textbook on process design, and is an Adjunct Professor at Northwestern University, where he teaches the senior design classes. Gavin has a B.A. and M.Eng. in chemical engineering from Cambridge University and a Ph.D. from U.C. Berkeley. He is a Chartered Engineer and Fellow of the Institute of Chemical Engineers, and is a Fellow of the AIChE.