This Practice provides requirements for use by a purchaser for determining the design criteria for double-pipe and multitube, and hairpin-type heat exchangers constructed in accordance with ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 or Division 2, henceforth referred to as the Code. Most standardized, predesigned (off-the-shelf) double-pipe and multitube hairpin-type heat exchangers meet the requirements of this Practice.