Seismic design for API 650 storage tanks

Above the water level, all API 650 storage tanks 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.

Corrosion allowance, if specified, shall be added to calculated API 650 tanks shell and self-supporting roof thicknesses; to minimum nominal thicknesses of bottom and supported API 650 storage tanks roof plates; to nozzles and manholes; and to all exposed surfaces of internal structural members and non-removable internals.

Sand blasting and derusting of API 650 storage tanks uses compressed air as power and SiC, pomegranate sand and quartz sand as spraying materials to form high-speed jet beam, which is used to remove rust and dirt on the surface of metal storage tank and improve the binding force of workpiece with coating and plating material. Sand blasting is often used in API 650 storage tanks construction.