In petroleum refineries, although there are sets of standard operating procedures to operate the plants, unique problems often arise, which need to be tackled with engineering knowledge and experience without much loss of energy and time. This process is termed ‘troubleshooting’, and it saves production loss, leading to profitability and sustainability of the refinery operation. This book covers the ins and outs of troubleshooting in petroleum refineries, with an analysis of the problems faced, the fundamentals behind them and logical reasoning and illustrations to solve the problems, along with lessons learnt. This is the first such book on the market since the publication of one by Norman P. Lieberman about 30 years ago, and there has been a massive change in technology since then. This book will not only enlighten practicing engineers in refineries and postgraduate students but also facilitate the creation of a knowledge bank on troubleshooting case studies, helping share engineering knowledge and experiences.