A841 Gr A Cl 1 plates API 650 unanchored tanks

Density of API 650 unanchored tanks Liquid Stored
The density of the liquid stored shall be its maximum density within the range of design temperatures, but no less than 29.3 lbf/ft3 for methane, 34.21 lbf/ft3 for ethane, and 35.5 lbf/ft3 for ethylene.
Design Metal Temperature
The design metal temperature of each component exposed to the liquid or vapor being stored shall be the lower of the temperatures specified as follows: The design metal temperature of the components of the API 620 single-wall tank or the inner tank of a double-wall tank shall be the minimum temperature to which the tank contents shall be refrigerated, including the effect of subcolony at reduced pressure."

The characteristics of the API 650 unanchored tanks internal floating roof structure of API 650 petroleum storage tanks: the inner floating roof or inner floating plate refers to the floating roof that floats on the liquid surface of the oil tank with the oil and liquid up and down. The API 650 unanchored tanks inner floating roof is used to cover the liquid. The surface is currently recognized as the most ideal and most economical and practical way to reduce oil evaporation loss.

Welding inspection of bottom plate of API 650 unanchored tanks, vertical oil tank: During the fabrication and installation of API 650 unanchored tanks, the bottom edge plate is welded first. According to the requirements of the technical standard, penetrant inspection is required for the weld of edge plate at the bottom of API 650 unanchored tanks, that is, penetrant testing is required for each weld bead priming, filling and capping. In the process of testing, if any defect is found, it shall be repaired immediately. After the repair, the surface coloring penetrant test shall be conducted again until the test result is qualified.