1.2.8. Selection of fluids for tube and the shell side

The routing of the shell side and tube side fluids has considerable effects on the heat exchanger design. Some general guidelines for positioning the fluids are given in Table 1.4. It should be understood that these guidelines are not ironclad rules and the optimal fluid placement depends on many factors that are service specific.

Table 1.4 . Guidelines for placing the fluid in order of priority

Tube-side fluid	Shell-side fluid
Corrosive fluid	Condensing vapor (unless corrosive)
Cooling water	Fluid with large temperature difference (>40°C)
Fouling fluid
Less viscous fluid
High-pressure steam
Hotter fluid