The shell is closed at both ends by the tubesheets. These normally have a considerable thickness and
are penetrated by the tubes. The tube-to-tubesheet joints must be hermetically sealed to avoid fluid leakage
from one side of the tubesheet to the other. One possible joint method is the welded construction indicated
in the detail of Fig. 6-1.
The tubesheets are bolted to the heads, which act as collectors and distributors of the fluid circulating
inside the tubes. This fluid enters the exchanger through a head nozzle and goes into and through the tubes
up to the opposite head, where it exits. The other fluid goes into the shell through an inlet nozzle, fills all the