Supplementary steel provides essential connections between building steel or ground to pipe supports and component supports of power and processing plants. This type of structure is usually with steel members less than 10 feet in length and sustains temperature within the range of the ambient conditions and the pipe or component. Being a connection, the standards and Codes provide an array of stress and geometrical checks that share that of a building and of a pressure boundary. Therefore, the applied engineering mechanics utilized in the analysis of supplemental steel configurations, including but not limited to beams, columns, and frames along with their welded or bolted connections, stretches across multiple engineering disciplines. A study of load cases and load case combinations is performed across multiple configurations of assemblies with industry assumptions incorporated. With the mitigation of sag of pipe systems, study of analytical stress and geometrical checks are evaluated to find any correlations of governing criteria. Additionally, the utilization of two types of structural steel design fundamentals and provisions, Allowable Strength Design (ASD) and Load and Resistance Factor Design (LRFD), are investigated with supplemental steel structures which stem from design considerations of steel buildings. This case study in the analysis of supplemental steel structures provides segue to highlighting how Codes and Standards utilized within the field that overlap other fields.