In modern practice, the basic design of a Shell & Tube-type Heat Exchanger, namely the thermal design, is performed using computer programs. These programs provide the computational speed needed for iterative simulation calculations and the accuracy required to apply numerous complex physical properties and coefficients precisely. The detailed structural design, or mechanical design, is carried out in accordance with the applicable standards and codes. Among these, the TEMA Standards of the Tubular Exchanger Manufacturers Association are by far the most widely used standards for the design and fabrication of Shell & Tube-type Heat Exchangers. TEMA not only provides a clear and systematic classification of the nomenclature and component types of Shell & Tube-type Heat Exchangers, but also establishes detailed technical criteria and requirements for manufacturing efficient and safe heat exchangers.