Thick-walled cylindrical steam headers are subject to varying amounts of circumferential stresses in their normal operating cycles... Analyzing the variations in the amount and the location of hoop stresses on different samples with varying material parameters would be an expensive option if done experimentally, but computational analysis results yield a more economical analysis of the problem presented, provided the boundary conditions prescribed immaculately replicate the operational conditions of the header computationally. This thesis deals with the computational finite element simulation of steam header sections with varying physical parameters and their effect on the circumferential stresses developed within the header when simulated with a nominal operating cycle using ABAQUS. The material chosen for the header is grade 91 steel and its physical properties were used for the simulation. Thirty steam header models of varying side tube penetration angles and varying cylinder wall thickness were used for the simulation to bring about a relationship between these variations and the circumferential stresses developed within the header. An additional three models were simulated to confirm the validity of the results.