API 12D 2017 pdf download.Specification for Field-welded Tanks for Storage of Production Liquids.
1 Scope 1.1 General This specification covers material, design, fabrication, and testing requirements for vertical, cylindrical, aboveground, closed top, welded steel storage tanks in various standard sizes and capacities for internal pressures of approximately atmospheric, not to exceed those listed in Table 5.1, Column 2. This specification provides the oil production industry with tanks of adequate safety and reasonable economy for use in the storage of crude petroleum and other liquids commonly handled and stored by the production segment of the industry. This specification is for the convenience of purchasers and manufacturers in ordering and fabricating tanks. 1.2 Compliance The manufacturer is responsible for complying with all provisions of this specification. The purchaser may make any investigation necessary to be satisfied that the manufacturer is in compliance and may reject any material that does not comply with this specification. It is urged that the purchaser exercise this right by providing an inspection independent of any supervisory inspection furnished by the manufacturer, and that the purchaser’s inspector closely monitor all of the details of shop fabrication and/or field construction and testing herein specified that may affect the integrity and safety of the completed structure. 2 Normative References The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document applies including any amendments. API Specification 5L, Specification for Line Pipe API Standard 650, Welded Tanks for Oil Storage API Recommended Practice 652, Lining of Aboveground Petroleum Storage Tank Bottoms API Standard 2000, Venting Atmospheric and Low-pressure Storage Tanks ASME Boiler and Pressure Vessel Code, Section IX 1 , Welding, Brazing, and Fusing Qualifications
3.5 butt weld A weld placed in a groove between abutting members. Grooves may be square, V-shaped (single or double), or U-shaped (single or double). 3.6 fillet weld A weld of approximately triangular cross section joining two surfaces approximately at right angles to each other, as in a lap joint, tee joint, or corner joint. 3.7 full-fillet weld A fillet weld whose size is equal to the thickness of the thinner member joined. 3.8 groove weld Weld beads that are deposited in a groove between two members to be joined. 3.9 tack weld A weld made to hold parts of a weldment in proper alignment until the final welds are made. 4 Materials 4.1 General The materials listed in this section have been selected to provide adequate strength and reasonable service life. Other materials having mechanical properties equal to or greater than these listed may be used by agreement between the purchaser and the manufacturer. Where higher strength materials are used, the minimum thicknesses called for in this specification shall not be reduced. 4.2 Plates 4.2.1 Plates shall conform to ASTM A36/A36M or ASTM A516/A516M. 4.2.2 Shell plates for which minimum thicknesses have been fixed for practical reasons (greater than required by computation) and that will not underrun the required computed thickness by more than 0.01 in., as well as all roof and bottom plates, may be purchased on a weight basis. The plate thicknesses or weights, as stipulated herein are minimums; thicker or heavier material may be required in the order at the option of the purchaser. 4.2.3 Rimmed or capped steels are not permitted. 4.3 Sheets 4.3.1 Sheets shall conform to ASTM A1011/A1011M, open-hearth process and basic oxygen process. Sheets may be ordered on a weight or thickness basis at the option of the tank manufacturer. 4.3.2 Rimmed or capped steels are not permitted.