ISO 630 Gr E275 plates API Std 650 self anchored flatbottom tanks

API 620 Crude Oil Tank Pneumatic Pressure
An air pressure equal to 1.25 times the pressure for which the vapor space is designed shall be applied to the enclosed space above the water level. In the case of a double-wall tank with an open-top inner tank, where the air pressure acts against the outer tank and the inner tank is thus not stressed by the air pressure, the inner API Std 650 self anchored flatbottom tanks may be emptied of water before the pneumatic pressure test begins. The test pressure shall be held for 1 hour.

The outer FRP of API 650 oil tank will not produce electrolytic corrosion with groundwater and brine. The outer FRP will not corrode with gasoline, diesel oil and leaded gasoline API Std 650 self anchored flatbottom tanks. The leakage detector can monitor the whole process 24 hours to eliminate the potential pollution. The leakage detection system is convenient for the inspection and maintenance of API 650 oil tank, and protects the original ecological environment of soil and groundwater.

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 Std 650 self anchored flatbottom 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.