This study compares two renowned methodologies, API 650 and API 579, focusing on the analysis of joint efficiency at a value of 0.7. Using Finite Element Analysis (FEA), the research suggests that a 35 % increase in filling height might be achievable for a large tank that adhere to the stability criteria outlined by API 650. To support these findings, 337 simulations rigorously examined various parameters. These encompass the design factor (β), bottom constraint, geometric configuration, mesh size, and a newly introduced Local ASME criterion. The latter is specifically introduced to evaluate protection against plastic collapse for Maximum Fill Height (MFH). Additionally, the study advocates elevating the joint efficiency from 0.7 to a range of 0.8–0.87 in API 653. This recommendation is pertinent to storage tanks that are not susceptible to buckling failure mode and possess limited documentation. The outcomes of this research provide significant insights into tank design and have the potential to refine industry standards and practices.