The domestic shell and tube graphite heat exchanger mostly uses phenolic graphite profiled tube, which is made of artificial graphite powder and phenolic resin according to a certain proportion, mixed and extruded. It is dense and hollow, and does not need resin impregnation or surface machining. However, the tank body itself must be cured completely, with smooth surface, no cracks and sand holes.

        When installing the heat exchanger, if the single tube pressure test and surface inspection are not strict, the graphite heat exchanger tubes which do not meet the above requirements may be misused. The heat exchange tube is fixed on the tubesheet in the form of bonding, which forms the binding effect of the tube bundle on the tubesheet.

        In production and application, the tubesheet is bound to deform under the action of medium pressure

        First, longitudinal tension or compression in different directions occurs between connecting devices;

        Secondly, with the uneven deformation of the parts of the heat exchanger, the tubesheet is flexed and the heat exchange tube is bent.

        However, if the defective graphite tubes are arranged in the area with large deformation, the graphite heat exchanger is easy to fracture and lead to leakage.