single-deck pontoon-type floating roof API Std 650 floating-roof tanks

Strictly controlling the temperature in the API Std 650 floating-roof tanks can effectively reduce the volatile consumption of oil in large oil storage tanks. Because the higher the temperature in the oil storage tank, the stronger the activity of oil molecules and the greater the volatilization consumption of the oil. Therefore, the temperature in the API Std 650 floating-roof tanks must be reduced as much as possible. It is possible to reduce the direct sunlight temperature by painting white anticorrosive paint with good light reflectivity. It is also possible to use spray equipment to wash the top and wall of the API Std 650 floating-roof tanks with water flow to reduce the volatilization consumption of the oil in the storage tank.

Preheating should be performed by heating and maintaining this heat in appreciable lengths of the joint to be welded, preferably using a strip burner with a mild flame rather than a harsh flame such as that from a cutting torch. Electrical strip heaters are available and have been found to be satisfactory. The preheat of 300°F should be checked with a temperature-sensitive crayon, or similarly accurate means, so that the steel 4 in. (or four times the API Std 650 floating-roof tanks plate thickness, whichever is greater) on each side of the joint will be maintained at the minimum preheat temperature. Ring burners or heaters are recommended for nozzle and manway welds. At no time during the welding should the base metal fall below a temperature of 300°F.

API 650 internal floating roof oil tank is a volatile liquid storage tank with a combination of a dome tank and an internal floating roof structure, which is a floating roof assembled under the dome of the API Std 650 floating-roof tanks storage tank. The combination of the vault roof outside the API 650 storage tank and the floating roof inside the tank has been widely used in gasoline, aviation kerosene and more volatile chemical liquids.