API 650 unanchored flat-bottom tank plates

Above the water level, all API 650 unanchored flat-bottom tank welded joints, all welds around openings, and all piping joints against which the pneumatic pressure is acting shall be checked with a solution film. A visual inspection may be substituted for the solution-film inspection if the welded joint has previously been checked with a vacuum box. The solution-film inspection shall still be made, above the water level, on all welds around openings, all piping joints, and the compression ring welds, including the attachment to the roof and shell.

Upon completion of construction, provide Purchaser with copies of Field Erected API 650 unanchored flat-bottom tank storage tank Datasheets in accordance with Appendix L of API 650, which reflects the as-built conditions, certifying that the tank conforms with the requirements of this specification.

Define the welding sequence of API 650 unanchored flat-bottom tank bottom plate: the welding sequence of metal vertical storage tank shall be carried out according to the procedure required by the welding scheme. Spot welding shall be consistent with the formal welding requirements, and no spot welding shall be carried out for the weld not welded. Back bar should be added to prevent deformation when welding the full length seam of middle plate, butt joint of edge plate and turtle shell joint.