Owing to its fewer sections and less surface area, a hairpin heat exchanger is the most efficient design when a process requires a temperature cross (hot fluid outlet temperature is below the cold fluid outlet temperature).
Process produces a temperature cross. High pressure tube-side application. Cyclic service. High flowrate ratios between shell- and tube-side fluids. High temperature difference (>300F / 149°C). Exchanger is subject to thermal shock. Heating or cooling vapors. Complete vaporization is required. Solids are present in the process stream.
Separate tube sheets handle high temperature differences and cycling more effectively. Durable baffle cage construction is welded to tie rods eliminating the need for sleeves or internal nuts. Moveable support brackets allow shell expansion and contraction and eliminate the need for sliding plates.
Double pipe exchangers and multi-tube hairpin exchangers with longitudinal fin pipes and fin tubes provide augmented heat transfer area in a compact arrangement saving space in applications where the shell side heat transfer coefficient is limiting e.g. low pressure gases and highly viscous fluids.
Double pipe heat exchangers utilize a single pipe within a pipe design and are commonly used in high fouling service e.g. slurries, with abrasives and smaller duties. Standard shell diameters from 2" to 6". Multi-tube exchangers are used for larger duties with standard shell diameters up to 30" and surface areas in excess of 10,000 ft2 per section.