The mechanical design of shell and tube heat exchanger(STHE) is critical in industrial applications. Basically the design is based on ASME codes and TEMA standards. A proper design of STHE helps in modifying the davit assembly for easy cleaning purposes. A good design is important for easier maintenance and improved efficiency. This book is intended to consolidate the basic concept of design and theoretical relationships useful in the design of heat exchangers. This book addresses several important issues such as design, installation, testing and maintenance. This book covers the topics such as components of STHE, classification, data needed for the design,tube side design, shell side design, tube layout, baffles, channel design, tie rod and spacers. This book is intended to help theoreticians for conceptual development of shell and tube heat exchanger.