API Std 650 self-anchored storage tanks seals

API Std 650 self-anchored storage tanks Liquid Relief ValvesA tank, which is likely to operate completely filled with liquid, shall be equipped with one or more liquid relief valves at the top of the roof, unless otherwise protected against overpressure. When such valves are, in effect, supplementary relief devices, they may be set at a pressure not greater than 1.25 times the design pressure. Because the relief valve at the pump, which provides the inflow of liquid to the tank, is set at a pressure greater than 1.25 times the design pressure of any tank that may be built under these rules, provision should be made for preventing overfilling of the tank by a self-closing float valve, by some practicable pilot-valve control, or by any other proven device.

API 650 "welded storage tanks" API Std 650 self-anchored storage tanks is a standard developed and issued by the American Petroleum Institute (API), which specifies the minimum requirements for the design, manufacture, installation and inspection of welded storage tanks.

When the day light gradually decreases, the temperature of oil in the API Std 650 self-anchored storage tanks will also decrease, the evaporation speed will gradually slow down, and the pressure in the API Std 650 self-anchored storage tanks will also decrease. When the pressure in the API Std 650 self-anchored storage tanks is lower than the negative pressure rating of the breathing valve, the outside air is sucked into the API Std 650 self-anchored storage tanks through the open vacuum valve, which is the "suction" process of the oil tank.