In what follows, the main features and characteristics of
shell-and-tube heat exchangers will be explained. This is by far the most common heat exchanger type
employed in the process industry. The design and construction of these units, as with any other pressure
vessel, normally follow the prescriptions of the American Society of Mechanical Engineers (ASME) Boiler
and Pressure Vessel Code, Section VII, Division 1. In U.S.A this code is mandatory in many States, and
because it is a recognized code, it is adopted in many projects around the world.