TEMA (R, C, B)

Key requirements (9)

• Mechanical standards for shell-and-tube exchangers — Class R (refinery/severe), C (commercial), B (chemical).
• Class R: heaviest construction — petroleum/petrochemical; 19 mm tube, 38 mm pitch typical.
• Class C: lightest — moderate service; 16 mm tube, 32 mm pitch typical.
• Class B: chemical process; intermediate.
• Type designation 3-letter (e.g. AES = removable channel, single-pass shell, floating head split-ring).
• Front end: A (channel/bonnet), B (bonnet integral), C (channel integral with TS), D (high-pressure closure).
• Shell types: E (1-pass), F (2-pass with longitudinal baffle), G (split-flow), H (double split-flow), J (divided flow), K (kettle), X (cross flow).
• Rear end: L–M (fixed TS), N (fixed integral channel), P–S–T (floating heads), U (U-tube), W (externally sealed floating).
• Standard impingement plate above 750 mass-velocity index ρv² for liquid shellside.