Design of an Optimum I-Beam Reinforcement for an API 620 Tank

The objective of this paper is to analyze an existing American Petroleum Institute (API) 620 Tank [10]. The API Tank had failed in the field. The tank is analyzed without reinforcement and with an optimum I-Beam reinforcement. The API Tank is used to store chemicals used in today’s industry. The initial over-all dimensions of the API Tank are determined from the capacity of the stored chemicals. The design function is performed using the ASME Code See VIII Div 1. The API Tank design is broken up into (a) bottom plate, (b) shell section with 9 mm thickness, (c) shell section with 8 mm thickness, (d) shell section with 7 mm thickness, (e) shell section with 6 mm thickness, (f) shell section with 5 mm thickness, (g) top head with 5mm thickness, (h) bolts, and (i) reinforcement ring. The designed dimensions are used to recalculate the stresses for the complete API Tank. The dimensioned API Tank without reinforcement is modeled first using STAAD III finite element software. The stresses from the finite element software are obtained. Next the API Tank with I-Beam reinforcement was modeled using STAAD III finite element software. Ten different I-Beams were considered for the present analysis. The main objective of this paper was to find the optimum I-Beam that resulted in safe reinforced configuration. Optimum I-Beam was considered to be the one that resulted in similar stresses for the beam as well as the tank. This assures elastic matching between the beam and the tank. The design is found to be safe for the I-Beam reinforced configuration considered.