Abstract: The calculation formula and checking conditions of the axial membrane stress σ_c in the shell side cylinder of fixed tubesheet heat exchangers are given in our country's standards GB/T 151 and JB 4732 for tube sheet calculation. The absolute value of the stress is checked according to allowable stress of the material without distinguishing whether it is tensile stress or compressive stress. Although the components of resultant force and moment V_s and M_s at the end of the shell connected with the tubesheet are obtained by solving the equations of deformation compatibility in JB 4732, the local bending stress at the end of the shell is not required to be further calculated. Aiming at the simplification of shell axial stress checking conditions in our national standards, this paper verifies the feasibility and rationality ofthe simplification through engineering examples and finite element analysis.

Key words: heat exchanger, shell side cylinder, axial stress, tubesheet