A516 Gr 450 plates API 650 SUG I tanks

There is no dome roof in the top of the vertical external floating roof oil storage tank, only the disc floating roof which can float up and down. The wall plates are connected by butt welding, and the construction is usually carried out by the forward installation method, and the storage capacity is usually more than 10000 cubic meters. Vertical internal floating roof API 650 SUG I tanks has both dome roof and internal floating roof. The internal floating roof floats on the liquid surface inside the dome roof oil tank and can float up and down. The storage capacity is usually between 1000 and 10000 cubic meters.

The hardness of the welds contacting these environments, including the heat-affected zones, shall be considered. The weld metal and adjacent heat-affected zone often contain a zone of hardness that is well in excess of a value of 22 on the Rockwell C scale and could be expected to be more susceptible to cracking than would unwelded metal. Any hardness criteria shall be a matter of agreement between the Purchaser and the API 650 SUG I tanks manufacturer and shall be based on an evaluation of the expected hydrogen sulfide concentration in the product, the possibility of moisture being present on the inside metal surface, and the strength and hardness characteristics of base metal and weld metal.

This standard establishes minimum requirements for API 650 tank material, API 650 SUG I tanks design, fabrication, erection, and inspection for ertical. aboveground，closed- and open-top.