Shell en tube grafiet heat exchangers

The standard shell and tube graphite heat exchangers comprises a steel shell enclosing a graphite tube bundle fitted with end covers.

Because of the differences in their coefficients of thermal expansion, (steel expands 2-3 times as much as graphite) the differential expansion between the steel shell and the graphite parts is taken up by the externally packed floating tubesheet. This compensate expansion and contraction of the shell over the tube bundle.

The graphite tube bundle is held in the shell by the stud holding the fixed tubesheet to the fixed end shell flange. These bolts remain in place to ensure that the tube bundle is restrained whenever the exchanger is in service, or subjected to pressure testing, or whenever the exchanger is moved. The fixed end cover is fixed to the fixed tubesheet by the stud between the pressure plate and the fixed end shell flange.

The floating end cover is held against the floating tubesheet by the stud between the pressure plate and the floating tubesheet flange. This flange holds a split ring, which is located in the groove in the floating tubesheet.

Floating Head Sliding Gland seals the shell and floating tubesheet employing a stuffing box.