A variety of unfired heat transfer equipment is used in industry, but the most common is the shell-and-tube exchanger. Although it is not especially compact, it has the advantage of being robust and versatile. Except for the special-purpose finned-tube air cooler, it is usually the only design that can be considered for large surface areas, pressures greater than 2 MNm², and temperatures greater than 250 °C.

As the name implies, a shell-and-tube heat exchanger consists of a shell (pressure vessel) containing a tube bundle, which is attached to stationary and rear heads. The tubes, which are attached to tubesheets, may be plain or finned, and run parallel to the longitudinal axis of the shell.

Section 413 deals with design and construction codes and describes a particular system for designating the various shell configurations, stationary heads, and rear heads. The design of the rear head establishes the type of shell-and-tube exchanger, and the different types, with variations, are described in Section 414. The purpose of the various stationary heads is described in Section 415. Section 416 and Section 417 deal with each component of a shell-and-tube heat exchanger and describe its thermal or mechanical function.

The nomenclature of the shell-and-tube heat exchanger components is given in Table 414.1.