In fixed tubesheet exchangers, the temperature differential between the shell and the tubes causes differential thermal expansion. Since the tubes are not free to move, severe stresses are induced in the tubes unless a provision is made to accommodate this expansion, especially in the case of high temperature units. The flanged and fluid expansion joint, installed on the shell side of a fixed tubesheet exchanger, accommodates this thermal expansion. This joint falls under the category of ring expansion joints and is commonly used. This paper describes the Fortran computer program which designs and analyzes flanged and flued exchanger expansion joints. The working of the program has been tested by analyzing the expansion joints and comparing theoretical results with those obtained from practice.