Structural evaluation on HSD oil storage tanks by hydrostatic method

High Speed Diesel (HSD) oil storage tank is a structure mainly composed of steel material. However, this structure is severe to have corrosion which occurs due to the chemical reaction between steel, moisture, and air. This paper investigated an HSD storage tank performance, located at PT. Arun Lhokseumawe. Such storage tank has not been operated for 16 years, in which the corrosions were exposed in several parts of tanks structure. In this present study, the tank performance was evaluated by the hydrostatic method as a testing procedure in American Petroleum Institute (API) code. That method was employed to reveal whether the time and corrosion may affect the serviceability of the tank structure. To perform the hydrostatic test, the tank was filled in with water with several water levels in the site and the behaviors were investigated. The observation showed that there were several leaks in the tank wall particularly in areas over 90% of tank height due to the corrosion and also indications of settlement and lateral deformation due to the watering process. The analytical study also confirmed the validity of actual deformation obtained from the site and showed that maximum stresses were located at the area close to the bottom plate due to the hydrostatic water pressure.