Abstract: Combining with the actual production, this paper analyzed the imperfections of the inner roof deck used in the atmospheric product oil tanks which belong to the company. It made comparison between different types of inner roof decks from technical and economic aspects. Then it proposed the upgrading scheme of replacing aluminum roof deck+gas capsule sealing with roof deck being in full contact with the liquid surface+elastic compensation seal. With the implementation of the new scheme, the previous defects in roof deck and sealing used in the product oil tanks were effectively eliminated. In addition, the oil and gas leakage was reduced and the problem of excessive VOCs emission from the tanks was solved. Tank shutdown and maintenance frequency decreased and the safety of oil tanks has been improved. As a result, economic loss was retrieved and the expected effects were achieved. Thus, the study has verified the effectiveness of the upgrading scheme of roof deck being in full contact with the liquid surface+elastic compensation seal for atmospheric internal floating roof tanks.

Key words: atmospheric storage tank, roof deck being in full contact with the liquid surface, elastic film seal, VOCs emission, safety, service life