The workhorse of industrial heat exchange. A tube bundle housed inside a cylindrical shell: one fluid flows through the tubes, the other around them in the shell. Simple in concept, unlimited in variants — nearly every refinery and chemical plant service fits into it.
TEMA classification
Three-letter nomenclature: front | shell | rear (e.g. BEM = front type B, shell type E, rear type M). Dominant decisions are:
- Shell: E (one pass), F (two-pass), J (split flow), K (kettle — reboiler with liquid pool).
- Rear: fixed (S, M, U-tube) or removable (T, W — free thermal expansion).
Reliability: tube corrosion (the dominant mode — cooling water, chlorides, H₂S), flow-induced vibration fatigue (FIV, common in shells with many tubes), fouling reducing calculated U, tubesheet integrity. Maintenance dominated by periodic hydrojetting and tube-by-tube leak testing with eddy current.