Abstract: Aiming at the visible quality defects of the inner steel tank of SF double skin oil tanks widely used in gas stations, the reasons for these defects are obtained through analysis based on the classifications including design defects, material defects, and manufacturing defects, as well as the evaluation of the impact of oil tank instability and oil tank leakage. The defects are caused by poor design ability of manufacturers and inadequate implementation of standards; weak skills of employees and outdated manufacturing processes; low-level of quality awareness and uncontrolled quality management. The lack of technical personnel or professional competence on the construction side, ambiguous technical standards in the contract, and formalistic inspection and acceptance are also partly responsible for the quality defects. Based on the provisions of relevant codes and standards and combined with the practice of project management, this paper presents the quality control measures for manufacturers and builders respectively. The research results can provide technical guidance and experience for the control of visible quality defects in the inner steel tanks of SF double skin oil tanks in gas stations.

Key words: SF double skin oil tank, inner steel tank, design, manufacture, quality defect, control measures