The API Downstream Segment has prepared thisstandard to cover large, field-assembled storage tanksof the type described in 1.2 that contain petroleumintermediates (gases or vapors) and finished products,as well as other liquid products commonly handled andstored by the various branches of the industry.The rules presented in this standard cannot cover alldetails of design and construction because of thevariety of tank sizes and shapes that may beconstructed. Where complete rules for a specificdesign are not given, the intent is for theManufacturer--subject to the approval of thePurchaser's authorized representative--to providedesign and construction details that are as safe asthose which would otherwise be provided by thisstandard.