U-Tube Heating Applications

Almost always the tubes. Steam is clean, so it suits the side that cannot be mechanically cleaned, and containing steam pressure in tubes is cheaper than in a shell. It also puts the process fluid on the shell side where the bundle can be withdrawn for cleaning.

Condensate that cannot leave, more often than fouling. A flooded exchanger loses effective surface progressively and looks identical to fouling from the control room. Check trap sizing and the drainage arrangement before you pull the bundle.

Tell us the turndown range at sizing. An exchanger sized only for peak load leaves the control valve operating near the bottom of its range, which produces unstable temperature and, on steam duty, can cause stall where condensate will not drain against back pressure.

Occasionally, on batch processes that alternate. It requires the design to be checked at both conditions and at the transition, and the thermal cycling that results is exactly what U-tube construction handles best.